EXHIBIT 10.17

                              AMENDED AND RESTATED
                                 LOAN AGREEMENT

                                      AMONG

                          AMERICAN TOWER SYSTEMS, INC.;

                  THE FINANCIAL INSTITUTIONS WHOSE NAMES APPEAR
                     AS BANKS ON THE SIGNATURE PAGES HEREOF;

                                       AND

                         TORONTO DOMINION (TEXAS), INC.,
                             AS ADMINISTRATIVE AGENT
                                  FOR THE BANKS


                          Dated as of October 15, 1997




                       Powell, Goldstein, Frazer & Murphy
                                Atlanta, Georgia








<PAGE>



<TABLE>
<CAPTION>
                                                 TABLE OF CONTENTS
                                                                                                               Page


<S>                                                                                                             <C>
ARTICLE 1             DEFINITIONS.................................................................................2

ARTICLE 2             LOANS......................................................................................20
         Section 2.1          The Loans..........................................................................20
         Section 2.2          Manner of Borrower and Disbursement................................................21
         Section 2.3          Interest...........................................................................23
         Section 2.4          Commitment Fees....................................................................25
         Section 2.5          Mandatory Commitment Reductions....................................................26
         Section 2.6          Voluntary Commitment Reductions....................................................28
         Section 2.7          Prepayments and Repayments.........................................................29
         Section 2.8          Notes; Loan Accounts...............................................................30
         Section 2.9          Manner of Payment..................................................................30
         Section 2.10         Reimbursement......................................................................31
         Section 2.11         Pro Rata Treatment.................................................................32
         Section 2.12         Capital Adequacy...................................................................32
         Section 2.13         Bank Tax Forms.....................................................................33

ARTICLE 3             CONDITIONS PRECEDENT.......................................................................33
         Section 3.1          Conditions Precedent to Effectiveness of this Amendment and Restatement               
         Section 3.2          Conditions Precedent to Each Advance...............................................35

ARTICLE 4             REPRESENTATIONS AND WARRANTIES.............................................................36
         Section 4.1          Representations and Warranties.....................................................36
         Section 4.2          Survival of Representations and Warranties, Etc....................................43

ARTICLE 5             GENERAL COVENANTS..........................................................................43
         Section 5.1          Preservation of Existence and Similar Matters......................................43
         Section 5.2          Business; Compliance with Applicable Law...........................................43
         Section 5.3          Maintenance of Properties..........................................................44
         Section 5.4          Accounting Methods and Financial Records...........................................44
         Section 5.5          Insurance..........................................................................44
         Section 5.6          Payment of Taxes and Claims........................................................45
         Section 5.7          Compliance with ERISA..............................................................45
         Section 5.8          Visits and Inspections.............................................................47
         Section 5.9          Payment of Indebtedness; Loans.....................................................47
         Section 5.10         Use of Proceeds....................................................................47
         Section 5.11         Real Estate........................................................................48
         Section 5.12         Indemnity..........................................................................48
         Section 5.13         Interest Rate Hedging..............................................................49
         Section 5.14         Covenants Regarding Formation of Restricted Subsidiaries and 
                              Acquisitions; Partnership, Subsidiaries............................................49



<PAGE>

<CAPTION>
                                                 TABLE OF CONTENTS
                                                    (Continued)
                                                                                                               Page


<S>                                                                                                             <C>
         Section 5.15         Payment of Wages...................................................................50
         Section 5.16         Further Assurances.................................................................50

ARTICLE 6             INFORMATION COVENANTS......................................................................51
         Section 6.1          Quarterly Financial Statements and Information.....................................51
         Section 6.2          Annual Financial Statements and Information........................................51
         Section 6.3          Performance Certificates...........................................................52
         Section 6.4          Copies of Other Reports............................................................52
         Section 6.5          Notice of Litigation and Other Matters.............................................53
         Section 6.6          Real Estate........................................................................54

ARTICLE 7             NEGATIVE COVENANTS.........................................................................54
         Section 7.1          Indebtedness of the Borrower and its Subsidiaries..................................54
         Section 7.2          Limitation on Liens................................................................55
         Section 7.3          Amendment and Waiver...............................................................55
         Section 7.4          Liquidation, Merger or Disposition of Assets.......................................55
         Section 7.5          Limitation on Guaranties...........................................................56
         Section 7.6          Investments and Acquisitions.......................................................57
         Section 7.7          Restricted Payments................................................................58
         Section 7.8          Leverage Ratio.....................................................................58
         Section 7.9          Interest Coverage Ratio............................................................59
         Section 7.10         Annualized Operating Cash Flow to Pro Forma Debt Service...........................59
         Section 7.11         Limitation on Capital Expenditures.................................................60
         Section 7.12         Affiliate Transactions.............................................................60
         Section 7.13         Real Estate........................................................................60
         Section 7.14         ERISA Liabilities..................................................................61
         Section 7.15         Sales and Leasebacks...............................................................61
                        
ARTICLE 8              DEFAULT...................................................................................61
         Section 8.1          Events of Default..................................................................61
         Section 8.2          Remedies...........................................................................64
         Section 8.3          Payments Subsequent to Declaration of Event of Default.............................66

ARTICLE 9             THE ADMINISTRATIVE AGENT...................................................................67
         Section 9.1          Appointment and Authorization......................................................67
         Section 9.2          Interest Holders...................................................................67
         Section 9.3          Consultation with Counsel..........................................................67
         Section 9.4          Documents..........................................................................67
         Section 9.5          Administrative Agent and Affiliates................................................68
         Section 9.6          Responsibility of the Administrative Agent.........................................68
         Section 9.7          Action by the Administrative Agent.................................................68


                                     - ii -
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<CAPTION>
                                                 TABLE OF CONTENTS
                                                    (Continued)
                                                                                                               Page


<S>                                                                                                             <C>
         Section 9.8          Notice of Default or Event of Default..............................................69
         Section 9.9          Responsibility Disclaimed..........................................................69
         Section 9.10         Indemnification....................................................................70
         Section 9.11         Credit Decision....................................................................70
         Section 9.12         Successor Administrative Agent.....................................................71
         Section 9.13         Delegation of Duties...............................................................71
                         
ARTICLE 10            CHANGES IN CIRCUMSTANCES AFFECTING LIBOR ADVANCES..........................................72
         Section 10.1         LIBOR Basis Determination Inadequate or Unfair.....................................72
         Section 10.2         Illegality.........................................................................72
         Section 10.3         Increased Costs....................................................................73
         Section 10.4         Effect On Other Advances...........................................................74
                       
ARTICLE 11            MISCELLANEOUS..............................................................................74
         Section 11.1         Notices............................................................................74
         Section 11.2         Expenses...........................................................................76
         Section 11.3         Waivers............................................................................76
         Section 11.4         Set-Off............................................................................77
         Section 11.5         Assignment.........................................................................77
         Section 11.6         Accounting Principles..............................................................80
         Section 11.7         Counterparts.......................................................................80
         Section 11.8         Governing Law......................................................................80
         Section 11.9         Severability.......................................................................81
         Section 11.10        Interest        ...................................................................81
         Section 11.11        Table of Contents and Headings.....................................................81
         Section 11.12        Amendment and Waiver...............................................................81
         Section 11.13        Entire Agreement...................................................................82
         Section 11.14        Other Relationships................................................................82
         Section 11.15        Directly or Indirectly.............................................................82
         Section 11.16        Reliance on and Survival of Various Provisions.....................................82
         Section 11.17        Senior Debt........................................................................83
         Section 11.18        Obligations........................................................................83
         Section 11.19        Confidentiality....................................................................83

ARTICLE 12            WAIVER OF JURY TRIAL.......................................................................83
         Section 12.1         Waiver of Jury Trial...............................................................83

</TABLE>

                                     - iii -
<PAGE>





                                    EXHIBITS

         Exhibit A                  Form of Activation Notice
         Exhibit B                  Form of Borrower's Pledge Agreement
         Exhibit C                  Form of Borrower's Security Agreement
         Exhibit D                  Form of Certificate of Financial Condition
         Exhibit E                  Form of Promissory Note
         Exhibit F                  Form of Parent Pledge Agreement
         Exhibit G              -   Form of Request for Advance
         Exhibit H              -   Form of Subsidiary Guaranty
         Exhibit I              -   Form of Subsidiary Pledge Agreement
         Exhibit J              -   Form of Subsidiary Security Agreement
         Exhibit K              -   Form of Use of Proceeds Letter
         Exhibit L              -   Form of Borrower's Loan Certificate
         Exhibit M              -   Form of Subsidiary Loan Certificate
         Exhibit N              -   Form of Performance Certificate
         Exhibit 0              -   Form of Assignment and Assumption Agreement



                                    SCHEDULES

         Schedule 1             -   Licenses
         Schedule 2             -   List of Unrestricted Subsidiaries on the 
                                    Agreement Date
         Schedule 4. 1 (a)      -   Exceptions to Representations and Warranties
         Schedule 4. 1 (c)      -   Subsidiaries
         Schedule 4. 1 (i)      -   Litigation
         Schedule 4. 1 (s)      -   Affiliate Transactions
         Schedule 4. I (v)      -   Indebtedness




                                     - iv -




<PAGE>



                              AMENDED AND RESTATED
                                 LOAN AGREEMENT
                                      AMONG
                          AMERICAN TOWER SYSTEMS, INC.;
                  THE FINANCIAL INSTITUTIONS WHOSE NAMES APPEAR
                     AS BANKS ON THE SIGNATURE PAGES HEREOF;
                                       AND
                         TORONTO DOMINION (TEXAS), INC.,
                             AS ADMINISTRATIVE AGENT
                                  FOR THE BANKS


         WHEREAS,  the Borrower,  the Administrative Agent and the Banks are all
parties to that certain Loan Agreement dated as of November 22, 1996 (the "Prior
Loan Agreement"); and

         WHEREAS,  the Borrower has requested that the Administrative  Agent and
the Banks  consent to certain  amendments to the Prior Loan  Agreement,  as more
fully set forth in this Amended and Restated Loan Agreement; and

         WHEREAS,  the  Administrative  Agent and the Banks have agreed to amend
and restate the Prior Loan Agreement in its entirety as set forth herein; and

         WHEREAS,  the  Borrower  acknowledges  and  agrees  that  the  security
interest  granted to the  Administrative  Agent, for itself and on behalf of the
Banks pursuant to the Prior Loan Agreement and the Loan Documents (as defined in
the  Prior  Loan  Agreement)  executed  in  connection  therewith  shall  remain
outstanding  and in full  force and  effect in  accordance  with the Prior  Loan
Agreement and shall continue to secure the Obligations (as defined therein); and

         WHEREAS, the Borrower  acknowledges and agrees that (i) the Obligations
(as defined herein) represent,  among other things, the amendment,  restatement,
renewal,  extension,  consolidation  and  modification  of the  Obligations  (as
defined in the Prior Loan  Agreement)  arising in connection with the Prior Loan
Agreement and the other Loan Documents (as defined in the Prior Loan  Agreement)
executed in connection therewith;  (ii) the parties hereto intend that the Prior
Loan  Agreement  and the other  Loan  Documents  (as  defined  in the Prior Loan
Agreement)   executed  in  connection   therewith  and  the  collateral  pledged
thereunder  shall secure,  without  interruption  or impairment of any kind, all
existing  Indebtedness  under  the  Prior  Loan  Agreement  and the  other  Loan
Documents  (as  defined  in the Prior Loan  Agreement)  executed  in  connection
therewith as so amended, restated, restructured, renewed, extended, consolidated
and modified hereunder, together with all other Obligations hereunder; (iii) all
Liens  evidenced by the Prior Loan  Agreement  and the 


<PAGE>

other  Loan  Documents  (as  defined in the Prior Loan  Agreement)  executed  in
connection therewith are hereby ratified,  confirmed and continued; and (iv) the
Loan Documents (as defined herein) are intended to restructure,  restate, renew,
extend,  consolidate,  amend and modify the Prior Loan  Agreement  and the other
Loan Documents (as defined in the Prior Loan  Agreement)  executed in connection
therewith; and

         WHEREAS, the parties hereto intend that (i) the provisions of the Prior
Loan  Agreement  and the other  Loan  Documents  (as  defined  in the Prior Loan
Agreement)  executed  in  connection  therewith,  to  the  extent  restructured,
restated,  renewed,  extended,  consolidated,  amended and modified hereby,  are
hereby  superseded  and  replaced  by the  provisions  hereof  and  of the  Loan
Documents  (as  defined  herein);  and (ii) the Notes (as  hereinafter  defined)
amend,  renew,  extend,  modify,  replace,  are substituted for and supersede in
their  entirety,  but do not  extinguish  the  indebtedness  arising  under  the
promissory notes issued pursuant to the Prior Loan Agreement;

         NOW, THEREFORE,  for good and valuable  consideration,  the receipt and
sufficiency of which are hereby  acknowledged by each of the parties hereto, the
parties hereby amend and restate the Prior Loan Agreement as follows:


                             ARTICLE 1 Definitions
         For the purposes of this Agreement:

         "Acquisition"  shall  mean  (whether  by  purchase,   lease,  exchange,
issuance of stock or other equity or debt securities,  merger, reorganization or
any  other  method)  (i)  any  acquisition  by the  Borrower  or any  Restricted
Subsidiary of any other Person, which Person shall then become consolidated with
the Borrower or any such Restricted Subsidiary in accordance with GAAP; (ii) any
acquisition  by  the  Borrower  or  any  Restricted  Subsidiary  of  all  or any
substantial part of the assets of any other Person;  or (iii) any acquisition by
Borrower or any Restricted  Subsidiary of any  communications  tower facilities,
communications tower management businesses or related contracts,  other than any
such Acquisition which shall be made by, or of, any Person which shall have been
designated and approved as an Unrestricted Subsidiary.

         "Acquisition  Operating  Cash  Flow"  shall  mean  in  the  case  of an
Acquisition  permitted  hereunder,  Operating  Cash Flow of the Borrower and its
Restricted  Subsidiaries  for the period during which such  Acquisition  occurs,
adjusted  (A) to give effect to such  Acquisition,  as if such  Acquisition  had
occurred on the first day of such period,  by excluding the Operating  Cash Flow
of such Acquisition during such period prior to the date of such Acquisition and
adding to the Operating Cash Flow of the Borrower,  if positive,  or subtracting
from such  Operating  Cash  Flow,  if  negative,  the  product of (i) the actual
Operating Cash Flow of such Acquisition for that portion of such period from the
date of 

                                      -2-
<PAGE>

such  Acquisition to the last day of such period,  multiplied by (ii) a fraction
the  numerator  of which is the number of  calendar  days in such period and the
denominator of which is the number of days in such period from and including the
date of such Acquisition through the last day of such period.

         "Activation  Notice"  shall  be a  notice  from  the  Borrower  to  the
Administrative  Agent in  substantially  the form of Exhibit A  attached  hereto
pursuant to which the Borrower notifies the Administrative  Agent on or prior to
October 15, 1998, that it is activating the Commitment Increase.

         "Administrative  Agent" shall mean Toronto Dominion  (Texas),  Inc., in
its  capacity  as   Administrative   Agent  for  the  Banks  or  any   successor
Administrative Agent appointed pursuant to Section 9.12 hereof.

         "Administrative   Agent's   Office"   shall  mean  the  office  of  the
Administrative  Agent located at 909 Fannin  Street,  Suite 1700,  Houston Texas
77010,  or such other office as may be designated  pursuant to the provisions of
Section 11.1 hereof.

         "Advance"  shall mean  amounts  advanced  by the Banks to the  Borrower
pursuant  to Article 2 hereof on the  occasion of any  borrowing  and having the
same Interest Rate Basis and Interest  Period;  and  "Advances"  shall mean more
than one Advance.

         "Affiliate"  shall mean,  with  respect to a Person,  any other  Person
directly or indirectly controlling, controlled by, or under common control with,
such first Person.  For purposes of this  definition,  "control"  when used with
respect to any  Person  includes,  without  limitation,  the direct or  indirect
beneficial  ownership of more than ten percent (10%) of the voting securities or
voting  equity of such Person or the power to direct or cause the  direction  of
the management and policies of such Person whether by contract or otherwise. For
purposes of this Agreement,  American Radio Systems and its Affiliates  shall be
deemed to be Affiliates of the Borrower.

         "Agreement"  shall mean this Amended and Restated  Loan  Agreement,  as
amended, supplemented, restated or otherwise modified from time to time.

         "Agreement Date" shall mean October 15, 1997.

         "American Radio Systems" shall mean American Radio Systems Corporation,
a Delaware corporation.

         "Annualized  Operating  Cash Flow"  shall mean (a) for any  calculation
date up to and including  September 30, 1998,  the sum of (i) the product of (A)
Operating Cash Flow (Towers) for the calendar month-end being tested or the most
recently completed  calendar

 
                                      -3-
<PAGE>

month immediately preceding such calculation date, as the case may be, times (B)
twelve (12) and (ii) the product of (A) Operating Cash Flow (Other Business) for
the  fiscal  quarter  end being  tested or the most  recently  completed  fiscal
quarter immediately preceding such calculation date, times (B) four (4); and (b)
for any calculation  date after September 30, 1998, the product of (i) Operating
Cash Flow for the fiscal quarter-end being tested or the most recently completed
fiscal quarter immediately  preceding such calculation date, as the case may be,
times (ii) four (4).

         "Applicable  Law" shall mean, in respect of any Person,  all provisions
of constitutions, statutes, rules, regulations and orders of governmental bodies
or regulatory  agencies applicable to such Person,  including,  without limiting
the foregoing,  the Licenses,  the Communications Act, zoning ordinances and all
Environmental  Laws,  and all orders,  decisions,  judgments  and decrees of all
courts and arbitrators in proceedings or actions to which the Person in question
is a party or by which it is bound.

         "Applicable  Margin" shall mean the interest rate margin  applicable to
Base  Rate  Advances  and  LIBOR  Advances,  as the  case may be,  in each  case
determined in accordance with Section 2.3(f) hereof.

         "Applicable  Margin Ratio" shall mean, as of any date, the ratio of (a)
the Total Debt of the Borrower and its Restricted Subsidiaries on a consolidated
basis on such date to (b) the product of (i) Operating Cash Flow of the Borrower
and its Restricted Subsidiaries,  for the most recently completed fiscal quarter
times (ii) four (4).

         "Authorized  Signatory" shall mean such senior personnel of a Person as
may be duly  authorized  and  designated  in writing  by such  Person to execute
documents, agreements and instruments on behalf of such Person.

         "Available  Commitment"  shall  mean  the  lesser  of (i) the  Existing
Commitment  and (ii) the maximum  amount of the Loans that could be  outstanding
hereunder on such date  without  resulting in a breach of Section 7.8 or Section
7.10 hereof.

         "Banks"  shall mean the Persons  whose  names  appear as "Banks" on the
signature  pages hereof and any other Person  which  becomes a "Bank"  hereunder
after the Agreement Date; and "Bank" shall mean any one of the foregoing Banks.

         "Base Rate" shall mean,  at any time, a  fluctuating  interest rate per
annum equal to the higher of (a) the rate of  interest  quoted from time to time
by the  Administrative  Agent as its  "prime  rate"  or  "base  rate" or (b) the
Federal  Funds Rate plus  one-half of one percent  (1/2%).  The Base Rate is not
necessarily the lowest rate of interest charged by the  Administrative  Agent in
connection with extensions of credit.



 
                                      -4-
<PAGE>

         "Base Rate Advance"  shall mean an Advance which the Borrower  requests
to be made as a Base Rate Advance or is reborrowed  as a Base Rate  Advance,  in
accordance  with the  provisions of Section 2.2 hereof,  and which shall be in a
principal  amount  of at  least  $1,000,000,  and  in an  integral  multiple  of
$500,000.

         "Base Rate Basis" shall mean a simple interest rate equal to the sum of
(i) the Base  Rate  and  (ii) the  Applicable  Margin  applicable  to Base  Rate
Advances.  The Base Rate Basis shall be adjusted automatically as of the opening
of business on the effective date of each change in the Base Rate to account for
such  change,  and shall also be adjusted to reflect  changes of the  Applicable
Margin applicable to Base Rate Advances.

         "Borrower"  shall  mean  American  Tower  Systems,   Inc.,  a  Delaware
corporation.

         "Borrower's  Pledge  Agreement"  shall mean that  certain  Amended  and
Restated  Borrower's Pledge Agreement dated as of even date herewith between the
Borrower and the  Administrative  Agent,  substantially in the form of Exhibit B
attached   hereto,   pursuant  to  which  the   Borrower   has  pledged  to  the
Administrative  Agent for the ratable benefit of the Banks all of the Borrower's
stock ownership and/or any partnership interests in each of its Subsidiaries.

         "Borrower's  Security  Agreement"  shall mean that certain  Amended and
Restated Security Agreement dated as of even date herewith, made by the Borrower
in favor of the  Administrative  Agent for the  ratable  benefit  of the  Banks,
substantially in the form of Exhibit C attached hereto.

         "Business  Day" shall mean a day on which  banks and  foreign  exchange
markets are open for the transaction of business  required for this Agreement in
Houston,  Texas,  New York,  New York and  London,  England,  as relevant to the
determination to be made or the action to be taken.

         "Capital  Expenditures"  shall  mean,  for  any  period,   expenditures
(including the aggregate amount of Capitalized Lease Obligations  required to be
paid during such period)  incurred by any Person to acquire or  construct  fixed
assets, plant and equipment (including renewals,  improvements and replacements,
but  excluding  repairs  and  maintenance)  during such  period,  which would be
required to be  capitalized  on the balance  sheet of such Person in  accordance
with GAAP.

         "Capital Stock" shall mean, as applied to any Person, any capital stock
of such Person, regardless of class or designation,  and all warrants,  options,
purchase rights,  conversion or exchange rights,  voting rights, calls or claims
of any character with respect thereto.



 
                                      -5-
<PAGE>

         "Capitalized   Lease   Obligation"  shall  mean  that  portion  of  any
obligation  of a Person  as  lessee  under a lease  which  at the time  would be
required to be  capitalized  on the balance  sheet of such lessee in  accordance
with GAAP.

         "Certificate  of  Financial   Condition"   shall  mean  a  certificate,
substantially  in the form of  Exhibit D  attached  hereto,  signed by the chief
financial  officer of the  Borrower,  together with any  schedules,  exhibits or
annexes appended thereto.

         "Change of Control"  shall mean (a) any change in the  ownership of, or
lien upon, the stock of the Borrower that results in less than fifty-one percent
(51%) of all voting  rights with  respect to the Capital  Stock of the  Borrower
(including,  without limitation,  warrants,  options,  conversion rights, voting
rights and calls or claims of any character with respect thereto,  to the extent
exercisable prior to repayment in full of the Obligations) being owned, directly
or indirectly,  by the Parent,  the senior management of American Radio Systems,
or Affiliates of American Radio Systems, the Parent or the Borrower or (b) after
any acquisition of all or  substantially  all of the assets or voting control of
the Capital Stock of American Radio Systems (whether by merger or other business
combination),  any event that results in Steven B. Dodge  ceasing to have one of
the following: (i) ownership of a material amount of the voting Capital Stock of
the  Borrower,  (ii)  ownership of a material  amount of the economic  ownership
interests  of the  Borrower  or (iii) the  position  of Chairman of the Board of
Directors and Chief Executive Officer.

         "Code"  shall mean the Internal  Revenue Code of 1986,  as amended from
time to time.

         "Collateral"   shall  mean  any  property  of  any  kind   constituting
collateral for the Obligations under any of the Security Documents.

         "Commitment"  shall mean the several  obligations  of the Banks to fund
their  respective  portion of the Loans to the Borrower in accordance with their
respective  Commitment  Ratios  in  the  aggregate  sum  of up to  $400,000,000,
pursuant to the terms hereof,  as such  obligations  may be reduced from time to
time pursuant to the terms hereof.

         "Commitment  Increase"  shall mean the pro rata increase to each Bank's
portion of the Existing Commitment from $250,000,000 to $400,000,000.

         "Commitment  Ratios" shall mean the  percentages in which the Banks are
severally  bound to fund their  respective  portion of Advances to the  Borrower
under the  Commitment,  which are set forth below (together with dollar amounts)
(and which may change from time to time in accordance with Section 11.5 hereof):



 
                                      -6-
<PAGE>

<TABLE>
<CAPTION>
                                                                       Approximate                      Dollar
                            Bank                                        Percentage                    Commitment

<S>                                                                      <C>                  <C>                 
Toronto Dominion (Texas), Inc.                                           8.750000000%         $         35,000,000
Banque Paribas                                                           6.750000000%         $         27,000,000
Barclays Bank PLC                                                        6.750000000%         $         27,000,000
Bank of Montreal, Chicago Branch                                         6.750000000%         $         27,000,000
The Chase Manhattan Bank                                                 6.750000000%         $         27,000,000
Fleet National Bank                                                      6.750000000%         $         27,000,000
GE Capital Corporation                                                   6.750000000%         $         27,000,000
The Bank of New York                                                     6.750000000%         $         27,000,000
Credit Suisse First Boston                                               6.750000000%         $         27,000,000
SunTrust Bank, Central Florida, National                                 6.750000000%         $         27,000,000
    Association
Union Bank of California, N.A.                                           6.750000000%         $         27,000,000
Credit Lyonnais New York Branch                                          6.250000000%         $         25,000,000
Lehman Commercial Paper Inc.                                             6.250000000%         $         25,000,000
The Bank of Nova Scotia                                                  3.750000000%         $         15,000,000
The Sumitomo Bank, Limited                                               3.750000000%         $         15,000,000
Bank of Scotland                                                         3.750000000%         $         15,000,000
TOTAL                                                                    100.00%              $        400,000,000
</TABLE>


         "Communications Act" shall mean the Communications Act of 1934, and any
similar or successor  federal statute,  and the rules and regulations of the FCC
thereunder, all as the same may be in effect from time to time.

         "Default"  shall  mean any  Event  of  Default,  and any of the  events
specified in Section 8.1 hereof, regardless of whether there shall have occurred
any passage of time or giving of notice,  or both,  that would be  necessary  in
order to constitute such event an Event of Default.

         "Default Rate" shall mean a simple per annum interest rate equal to the
sum of (a) the Base Rate, plus (b) the Applicable  Margin for Base Rate Advances
plus (c) two percent (2%).

         "Diablo"   shall  mean  Diablo   Communications,   Inc.,  a  California
corporation,   and  Diablo  Communications  of  Southern  California,   Inc.,  a
California corporation.

         "Employee  Pension Plan" shall mean any Plan which is maintained by the
Borrower, any of its Subsidiaries or any ERISA Affiliate.

         "Environmental Laws" shall mean all applicable federal,  state or local
laws,  statutes,  rules,  regulations or ordinances,  codes, common law, consent
agreements,  orders,  decrees,

 
                                      -7-
<PAGE>

judgments or injunctions  issued,  promulgated,  approved or entered  thereunder
relating  to  public  health,  safety  or the  pollution  or  protection  of the
environment,   including,   without  limitation,  those  relating  to  releases,
discharges,  emissions,  spills,  leaching,  or disposals to air, water, land or
ground water, to the withdrawal or use of ground water, to the use,  handling or
disposal of polychlorinated  biphenyls,  asbestos or urea  formaldehyde,  to the
treatment,  storage,  disposal or management of hazardous substances (including,
without  limitation,  petroleum,  crude oil or any  fraction  thereof,  or other
hydrocarbons),  pollutants or contaminants,  to exposure to toxic,  hazardous or
other  controlled,  prohibited,  or  regulated  substances,  including,  without
limitation, any such provisions under the Comprehensive  Environmental Response,
Compensation and Liability Act of 1980, as amended (42 U.S.C. ss. 9601 et seq.),
or the Resource Conservation and Recovery Act of 1976, as amended (42 U.S.C. ss.
6901 et seq.).

         "ERISA" shall mean the Employee Retirement Income Security Act of 1974,
as in effect from time to time.

         "ERISA  Affiliate" shall mean any Person,  including a Subsidiary or an
Affiliate of the  Borrower,  that is a member of any group of  organizations  of
which the Borrower is a member and which is covered by a Plan.

         "Eurodollar  Reserve  Percentage" shall mean the percentage which is in
effect from time to time under  Regulation  D of the Board of  Governors  of the
Federal Reserve System,  as such regulation may be amended from time to time, as
the  maximum  reserve  requirement   applicable  with  respect  to  Eurocurrency
Liabilities  (as that term is defined in Regulation  D), whether or not any Bank
has any such  Eurocurrency  Liabilities  subject to such reserve  requirement at
that time.

         "Event of Default"  shall mean any of the events  specified  in Section
8.1 hereof,  provided that any requirement for notice or lapse of time, or both,
has been satisfied.

         "Existing   Commitment"   shall  mean  (a)  prior  to  receipt  by  the
Administrative  Agent of an  Activation  Notice and from and after  October  15,
1998,  if no such  Activation  Notice has been  received  by the  Administrative
Agent,  and after giving effect to reductions in the Existing  Commitment  under
Section 2.5 and Section 2.6 hereof and repayments of the Loans under Section 2.7
hereof,  $250,000,000,  and (b) thereafter, after giving effect to reductions in
the Existing  Commitment under Section 2.5 and Section 2.6 hereof and repayments
of the Loans under Section 2.7 hereof, the Commitment.

         "Excess Cash Flow" shall mean,  as of the end of any fiscal year of the
Borrower based on the audited  financial  statements  provided under Section 6.2
hereof for such fiscal year, the excess,  if any, of (a) Operating Cash Flow for
such fiscal year,  minus (b) the sum of the  following:  (i) payments  made with
respect to Capital  Expenditures  incurred by 


                                       -8-
<PAGE>

the  Borrower and its  Restricted  Subsidiaries  during such fiscal  year;  (ii)
repayments of the Loans resulting from reductions of the Commitment (which shall
include any  reductions set forth in Section  2.5(a)  hereof);  (iii) cash taxes
paid by the  Borrower and its  Restricted  Subsidiaries  (including  any paid to
American Radio Systems pursuant to the Tax Sharing Agreement) during such fiscal
year; (iv) Interest Expense during such fiscal year; and (v) principal  payments
made in respect of  Indebtedness  for Money Borrowed (other than with respect to
the Loans) paid by the  Borrower  and its  Restricted  Subsidiaries  during such
fiscal year.

         "FCC" shall mean the Federal  Communications  Commission,  or any other
similar  or  successor  agency  of  the  federal  government  administering  the
Communications Act.

         "Federal Funds Rate" shall mean, as of any date,  the weighted  average
of the rates on overnight  federal  funds  transactions  with the members of the
Federal Reserve System arranged by federal funds brokers,  as published for such
day (or, if such day is not a Business Day, for the next preceding Business Day)
by the Federal Reserve Bank of New York or, if such rate is not so published for
any day which is a Business Day, the average of the  quotations  for such day on
such transactions  received by the  Administrative  Agent from three (3) federal
funds brokers of recognized standing selected by the Administrative Agent.

         "GAAP" shall mean, as in effect from time to time,  generally  accepted
accounting principles in the United States, consistently applied.

         "Guaranty" or "Guaranteed," as applied to an obligation, shall mean and
include (a) a guaranty, direct or indirect, in any manner, of all or any part of
such  obligation,  and (b) any  agreement,  direct or  indirect,  contingent  or
otherwise,  the practical effect of which is to assure in any way the payment or
performance  (or payment of damages in the event of  non-performance)  of all or
any part of such  obligation,  including,  without  limiting the foregoing,  any
reimbursement   obligations  as  to  amounts  drawn  down  by  beneficiaries  of
outstanding letters of credit or capital call requirements.

         "Indebtedness"  shall mean,  with  respect to any  Person,  and without
duplication,  (a) all items,  except items of shareholders' and partners' equity
or capital  stock or surplus or general  contingency  or deferred tax  reserves,
which in accordance with GAAP would be included in determining total liabilities
as shown on the  liability  side of a balance  sheet of such Person,  including,
without limitation, with respect to any secured non-recourse obligations of such
Person,  the higher of the book value or fair  market  value of the  property or
asset securing such obligation (if less than the amount of such obligation), (b)
all direct or indirect  obligations  of any other Person  secured by any Lien to
which any  property or asset  owned by such  Person is subject,  but only to the
extent of the higher of the fair market  value or the book value of the property
or asset subject to such Lien (if less than the amount of such  obligation),  if
the obligation  secured  thereby shall not have been assumed,  (c) to the extent
not otherwise included, all Capitalized Lease Obligations of such Person and all
obligations


                                       -9-
<PAGE>

of such Person with respect to leases constituting part of a sale and lease-back
arrangement,  (d) all  reimbursement  obligations  with  respect to  outstanding
letters of credit, and (e) to the extent not otherwise included, all obligations
subject  to  Guaranties  of  such  Person  or  its  Subsidiaries,  and  (f)  all
obligations of such Person under Interest Hedge Agreements.

         "Indebtedness  for Money  Borrowed"  shall  mean,  with  respect to any
Person,  Indebtedness for money borrowed and  Indebtedness  represented by notes
payable and drafts accepted  representing  extensions of credit, all obligations
evidenced  by  bonds,  debentures,  notes  or  other  similar  instruments,  all
Indebtedness  upon which interest charges are customarily paid (other than trade
payables arising in the ordinary course of business,  but only if and so long as
such  accounts are payable on customary  trade  terms),  all  Capitalized  Lease
Obligations,  all reimbursement  obligations with respect to outstanding letters
of credit,  all  Indebtedness  issued or assumed as full or partial  payment for
property or services  (other than trade payables  arising in the ordinary course
of business,  but only if and so long as such  accounts are payable on customary
trade terms), whether or not any such notes, drafts, obligations or Indebtedness
represent Indebtedness for money borrowed, and, without duplication,  Guaranties
of any of the  foregoing.  For purposes of this  definition,  interest  which is
accrued but not paid on the scheduled due date for such interest shall be deemed
Indebtedness for Money Borrowed.

         "Indemnitee"  shall have the meaning  ascribed  thereto in Section 5.12
hereof.

         "Interest  Coverage Ratio" shall mean, for any period, the ratio of (a)
Annualized  Operating Cash Flow as of (i) the calendar quarter end being tested,
or (ii) the most recently completed calendar quarter, as the case may be, to (b)
Interest Expense for (i) the four (4) calendar quarter period then ended or (ii)
the most recently  completed four (4) calendar  quarter period,  as the case may
be, in each case calculated in accordance with GAAP.

         "Interest  Expense"  shall  mean,  for any  period,  all cash  interest
expense   (including   imputed  interest  with  respect  to  Capitalized   Lease
Obligations) with respect to any Indebtedness for Money Borrowed of the Borrower
and its  Restricted  Subsidiaries  on a  consolidated  basis  during such period
pursuant to the terms of such Indebtedness for Money Borrowed, together with all
fees payable in respect thereof, all as calculated in accordance with GAAP.

         "Interest  Hedge  Agreements"  shall mean the obligations of any Person
pursuant  to  any  arrangement  with  any  other  Person  whereby,  directly  or
indirectly,  such  Person is  entitled  to  receive  from time to time  periodic
payments calculated by applying either a floating or a fixed rate of interest on
a stated notional  amount in exchange for periodic  payments made by such Person
calculated  by  applying  a fixed or a  floating  rate of  interest  on the same
notional  amount and shall  include,  without  limitation,  interest rate swaps,
caps, floors, collars and similar agreements.




                                      -10-
<PAGE>

         "Interest  Period"  shall  mean (a) in  connection  with any Base  Rate
Advance, the period beginning on the date such Advance is made and ending on the
last day of the  calendar  quarter  in which  such  Advance  is made,  provided,
however,  that if a Base Rate  Advance  is made on the last day of any  calendar
quarter,  it shall have an Interest Period ending on, and its Payment Date shall
be, the last day of the following  calendar quarter,  and (b) in connection with
any  LIBOR  Advance,  the  term of such  Advance  selected  by the  Borrower  or
otherwise  determined in accordance  with this  Agreement.  Notwithstanding  the
foregoing, however, (i) any applicable Interest Period which would otherwise end
on a day which is not a Business  Day shall be extended  to the next  succeeding
Business Day unless,  with respect to LIBOR  Advances  only,  such  Business Day
falls in another calendar month, in which case such Interest Period shall end on
the next  preceding  Business Day, (ii) any  applicable  Interest  Period,  with
respect to LIBOR  Advances  only,  which  begins on a day for which  there is no
numerically  corresponding  day in the calendar month during which such Interest
Period is to end shall (subject to clause (i) above) end on the last day of such
calendar month, and (iii) the Borrower shall not select an Interest Period which
extends  beyond the Maturity Date or such earlier date as would  interfere  with
the Borrower's  repayment  obligations under Section 2.5, Section 2.6 or Section
2.7 hereof.  Interest  shall be due and payable  with  respect to any Advance as
provided in Section 2.3 hereof.

         "Interest  Rate  Basis"  shall  mean the Base  Rate  Basis or the LIBOR
Basis, as appropriate.

         "known to the  Borrower" or "to the  knowledge of the  Borrower"  shall
mean known by or reasonably should have been known by the executive  officers of
the Borrower  (which shall  include,  without  limitation,  the chief  executive
officer,  the chief operating  officer,  if any, the chief financial officer and
the general counsel, or any vice president of the Borrower).

         "Leverage Ratio" shall mean, as of any date, the ratio of (a) the Total
Debt of the Borrower and its Restricted  Subsidiaries on a consolidated basis on
such  date,  to (b)  Annualized  Operating  Cash  Flow of the  Borrower  and its
Restricted Subsidiaries on a consolidated basis.

         "LIBOR"  shall  mean,  for any  Interest  Period,  the  average  of the
interest  rates per annum at which  deposits in United  States  Dollars for such
Interest Period are offered to the Administrative Agent in the Eurodollar market
at approximately 11:00 a.m. (London time) two (2) Business Days before the first
day of such Interest Period, in an amount  approximately  equal to the principal
amount of, and for a length of time  approximately  equal to the Interest Period
for, the LIBOR Advance sought by the Borrower.




                                      -11-
<PAGE>

         "LIBOR Advance" shall mean an Advance which the Borrower requests to be
made as a LIBOR Advance or which is reborrowed as a LIBOR Advance, in accordance
with the  provisions  of Section 2.2  hereof,  and which shall be in a principal
amount of at least $5,000,000 and in an integral multiple of $1,000,000.

         "LIBOR  Basis"  shall mean a simple per annum  interest  rate  (rounded
upward,  if necessary,  to the nearest  one-hundredth  (1/100th) of one percent)
equal to the sum of (a) the quotient of (i) the LIBOR  divided by (ii) one minus
the Eurodollar  Reserve  Percentage,  if any, stated as a decimal,  plus (b) the
Applicable  Margin.  The LIBOR Basis shall apply to Interest Periods of one (1),
two (2),  three (3), or six (6)  months,  and,  once  determined,  shall  remain
unchanged during the applicable  Interest Period,  except for changes to reflect
adjustments in the Eurodollar  Reserve  Percentage and the Applicable  Margin as
adjusted  pursuant  to  Section  2.3(f)  hereof.  The LIBOR  Basis for any LIBOR
Advance  shall  be  adjusted  as of the  effective  date  of any  change  in the
Eurodollar Reserve Percentage.

         "Licenses" shall mean any telephone,  microwave,  radio  transmissions,
personal  communications  or  other  license,   authorization,   certificate  of
compliance,  franchise,  approval or permit,  whether for the construction,  the
ownership or the operation of any  communications  tower facilities,  granted or
issued  by  the  FCC  and  held  by  the  Borrower  or  any  of  its  Restricted
Subsidiaries,  all of which as of the  Agreement  Date are listed on  Schedule 1
attached hereto.

         "Lien" shall mean,  with respect to any property,  any mortgage,  lien,
pledge,  negative pledge or other agreement not to pledge,  assignment,  charge,
security  interest,  title  retention  agreement,   levy,  execution,   seizure,
attachment,  garnishment  or other  encumbrance  of any kind in  respect of such
property, whether created by statute, contract, the common law or otherwise, and
whether or not choate, vested or perfected.

         "Loan Documents"  shall mean this Agreement,  the Notes, the Borrower's
Pledge Agreement,  the Borrower's  Security  Agreement,  the Subsidiary Security
Agreement,  the Subsidiary Guaranty, the Subsidiary Pledge Agreement, the Parent
Pledge Agreement,  all fee letters, all Requests for Advance, all Interest Hedge
Agreements between the Borrower,  on the one hand, and the Administrative  Agent
and the Banks,  or any of them, on the other hand,  and all other  documents and
agreements executed or delivered by the Borrower or its Restricted  Subsidiaries
in connection with or contemplated by this Agreement.

         "Loans" shall mean, collectively,  the amounts advanced by the Banks to
the Borrower under the Commitment,  not to exceed the Commitment,  and evidenced
by the Notes.

         "Majority  Banks"  shall  mean  (i) at  any  time  that  no  Loans  are
outstanding  hereunder,  Banks the total of whose  Commitment  Ratios  equals or
exceeds sixty percent (60%) of the  Commitment  Ratios of all Banks  entitled to
vote hereunder,  or (ii) at any time that there are 


                                      -12-
<PAGE>

Loans outstanding  hereunder,  Banks the total of whose Loans outstanding equals
or exceeds sixty percent (60%) of the total  principal  amount of the Loans then
outstanding of all Banks entitled to vote hereunder.

         "Materially  Adverse Effect" shall mean (a) any material adverse effect
upon the business, assets, business prospects, liabilities, financial condition,
results  of  operations  or  properties  of  the  Borrower  and  its  Restricted
Subsidiaries  on a  consolidated  basis,  taken  as a whole,  or (b) a  material
adverse effect upon the binding  nature,  validity,  or  enforceability  of this
Agreement and the Notes,  or upon the ability of the Borrower and its Restricted
Subsidiaries  to perform the payment  obligations or other material  obligations
under  this  Agreement  or any  other  Loan  Document,  or upon the value of the
Collateral or upon the rights,  benefits or interests of the Banks in and to the
Loans or the rights of the Administrative Agent and the Banks in the Collateral;
in either case,  whether  resulting  from any single act,  omission,  situation,
status, event or undertaking, or taken together with other such acts, omissions,
situations, statuses, events or undertakings.

         "Maturity  Date" shall mean June 30, 2005, or, as the case may be, such
earlier  date  as  payment  of  the   Obligations   shall  be  due  (whether  by
acceleration, reduction of the Commitment to zero or otherwise).

         "MicroNet"  shall mean  Suburban  Cable TV Co.,  Inc.,  a  Pennsylvania
corporation.

         "Multiemployer Plan" shall mean a multiemployer pension plan as defined
in Section 3(37) of ERISA to which the Borrower,  any of its Subsidiaries or any
ERISA Affiliate is or has been required to contribute.

         "Necessary  Authorizations" shall mean all approvals and licenses from,
and all filings and  registrations  with, any  governmental or other  regulatory
authority,  including,  without  limiting  the  foregoing,  the Licenses and all
approvals,  licenses,  filings and registrations  under the Communications  Act,
necessary  in order to enable the Borrower and its  Restricted  Subsidiaries  to
own, construct,  maintain,  and operate  communications  tower facilities and to
invest  in other  Persons  who own,  construct,  maintain,  manage  and  operate
communications tower facilities.

         "Net  Income"  shall  mean,   for  the  Borrower  and  its   Restricted
Subsidiaries on a consolidated  basis, for any period,  net income determined in
accordance with GAAP.

         "Net Proceeds" shall mean, with respect to any sale, lease, transfer or
other   disposition  of  assets  by  the  Borrower  or  any  of  its  Restricted
Subsidiaries,  the aggregate amount of cash received for such assets (including,
without  limitation,   any  payments  received  for  noncompetition   covenants,
consulting or management  fees in connection  with such sale, and any portion of
the  amount  received  evidenced  by a  promissory  note or  other  


                                      -13-
<PAGE>

evidence of Indebtedness issued by the purchaser),  net of (i) amounts reserved,
if any,  for taxes  payable  with  respect to any such sale  (after  application
(assuming  application first to such reserves) of any available losses,  credits
or other  offsets),  (ii)  reasonable and customary  transaction  costs properly
attributable  to such  transaction  and  payable by the  Borrower  or any of its
Restricted  Subsidiaries  (other than to an Affiliate)  in connection  with such
sale,  lease,  transfer  or other  disposition  of  assets,  including,  without
limitation,  commissions,  and (iii) until actually  received by the Borrower or
any of its Restricted  Subsidiaries,  any portion of the amount received held in
escrow or  evidenced  by a  promissory  note or other  evidence of  Indebtedness
issued by a purchaser or  non-compete,  consulting  or  management  agreement or
covenant or otherwise for which  compensation is paid over time. Upon receipt by
the Borrower or any of its Restricted Subsidiaries of (A) amounts referred to in
item (iii) of the preceding sentence,  or (B) if there shall occur any reduction
in the tax reserves referred to in item (i) of the preceding  sentence resulting
in a payment  to the  Borrower,  such  amounts  shall  then be deemed to be "Net
Proceeds."

         "Notes" shall mean, collectively, those certain promissory notes in the
aggregate original  principal amount of $400,000,000,  and issued to each of the
Banks by the Borrower,  each one substantially in the form of Exhibit E attached
hereto,  any other  promissory note issued by the Borrower to evidence the Loans
pursuant to this Agreement,  and any extensions,  renewals, or amendments to, or
replacements of, the foregoing.

         "Obligations"  shall mean all payment and  performance  obligations  of
every kind, nature and description of the Borrower, its Restricted Subsidiaries,
and any other  obligors to the Banks,  or the  Administrative  Agent,  or any of
them, under this Agreement and the other Loan Documents (including any interest,
fees and other charges on the Loans or otherwise  under the Loan  Documents that
would  accrue  but for the filing of a  bankruptcy  action  with  respect to the
Borrower,  whether or not such claim is  allowed in such  bankruptcy  action and
including  Obligations to the Banks pursuant to Section 5.13 hereof) as they may
be amended from time to time,  or as a result of making the Loans,  whether such
obligations  are direct or  indirect,  absolute or  contingent,  due or not due,
contractual or tortious, liquidated or unliquidated, arising by operation of law
or otherwise, now existing or hereafter arising.

         "Operating  Cash Flow" shall mean, with respect to the Borrower and its
Restricted Subsidiaries on a consolidated basis as of the end of any period, (a)
the  sum  of  (i)  operating   revenues  of  the  Borrower  and  its  Restricted
Subsidiaries plus (ii) Unrestricted Subsidiary  Distributions during such period
less (b) the sum of (i) operating  expenses for such period plus (ii)  corporate
overhead  (exclusive of amortization and  depreciation)  for such period. In the
case of  determining  Operating  Cash Flow under Sections 2.3, 7.8, 7.9 and 7.10
hereof following an Acquisition permitted hereunder,  Operating Cash Flow of the
Borrower and its Restricted Subsidiaries shall include the Acquisition Operating
Cash Flow.  For purposes of calculating  Operating Cash Flow in connection  with
any Advance for an  Acquisition,  Operating  Cash Flow for the  Borrower and its
Restricted Subsidiaries as of the last day of the 


                                      -14-
<PAGE>

immediately  preceding  calendar  quarter and/or calendar month end, as the case
may be, shall include  "operating  cash flow" for the  Acquisition  for the same
period after giving effect to pro forma adjustments  reasonably  satisfactory to
the Administrative Agent.

         "Operating Cash Flow (Towers)" shall mean, with respect to the Borrower
and its Restricted  Subsidiaries  on a  consolidated  basis as of the end of any
period, (a) the sum of (i) operating revenues of the Borrower and its Restricted
Subsidiaries in connection with the Tower Operation Business of the Borrower and
its Restricted Subsidiaries plus (ii) Unrestricted Subsidiary Distributions with
respect to the Tower  Operation  Business during such period less (b) the sum of
(i) operating  expenses  attributable to such Tower Operation  Business for such
period plus (ii) corporate overhead (exclusive of amortization and depreciation)
attributable  to such Tower Operation  Business for such period.  In the case of
determining  Operating  Cash Flow under  Sections  2.3, 7.8, 7.9 and 7.10 hereof
following  an  Acquisition  permitted  hereunder,  Operating  Cash  Flow  of the
Borrower and its Restricted Subsidiaries shall include the Acquisition Operating
Cash Flow.  For purposes of calculating  Operating Cash Flow in connection  with
any Advance for an  Acquisition,  Operating  Cash Flow for the  Borrower and its
Restricted Subsidiaries as of the last day of the immediately preceding calendar
month end shall include  "operating  cash flow" for the Acquisition for the same
period  after  giving  effect  to  adjustments  reasonably  satisfactory  to the
Administrative Agent.

         "Operating Cash Flow (Other  Business)" shall mean, with respect to the
Borrower and its Restricted  Subsidiaries on a consolidated  basis as of the end
of any period,  (a) the sum of (i)  operating  revenues of the  Borrower and its
Restricted  Subsidiaries in connection with the Other Operations of the Borrower
and its Restricted Subsidiaries plus (ii) Unrestricted Subsidiary  Distributions
with respect to the Other Operations  during such period less (b) the sum of (i)
operating  expenses  attributable to such Other  Operations for such period plus
(ii)  corporate   overhead   (exclusive  of   amortization   and   depreciation)
attributable  to  such  Other  Operations  for  such  period.  In  the  case  of
determining  Operating  Cash Flow under  Sections  2.3, 7.8, 7.9 and 7.10 hereof
following  an  Acquisition  permitted  hereunder,  Operating  Cash  Flow  of the
Borrower and its Restricted Subsidiaries shall include the Acquisition Operating
Cash Flow.  For purposes of calculating  Operating Cash Flow in connection  with
any Advance for an  Acquisition,  Operating  Cash Flow for the  Borrower and its
Restricted Subsidiaries as of the last day of the immediately preceding calendar
month end shall include  "operating  cash flow" for the Acquisition for the same
period  after  giving  effect  to  adjustments  reasonably  satisfactory  to the
Administrative Agent.

         "Other  Operations"  shall mean all  businesses of the Borrower  (other
than the Tower Operations Business),  including,  without limitation,  the video
and data transmission and the site acquisition business.




                                      -15-
<PAGE>

         "Parent"  shall mean American  Tower  Systems  Holding  Corporation,  a
Delaware corporation.

         "Parent Pledge  Agreement" shall mean that certain Amended and Restated
Parent Pledge Agreement dated as of even date herewith,  made by Parent in favor
of the Administrative Agent for the ratable benefit of the Banks,  substantially
in the form of Exhibit F attached hereto.

         "Payment Date" shall mean the last day of any Interest Period.

         "PBGC"  shall mean the Pension  Benefit  Guaranty  Corporation,  or any
successor thereto.

         "Permitted Liens" shall mean, as applied to any Person:

                  (a) any  Lien in favor of the  Administrative  Agent  given to
secure the Obligations;

                  (b) (i) Liens on real  estate  or other  property  for  taxes,
assessments,  governmental  charges or levies not yet  delinquent and (ii) Liens
for taxes, assessments,  judgments, governmental charges or levies or claims the
non-payment of which is being diligently  contested in good faith by appropriate
proceedings and for which adequate reserves have been set aside on such Person's
books,  but  only  so  long  as  no  foreclosure,  distraint,  sale  or  similar
proceedings have been commenced with respect thereto;

                  (c)  Liens  of  carriers,  warehousemen,  mechanics,  vendors,
(solely to the extent  arising by  operation of law)  laborers  and  materialmen
incurred  in the  ordinary  course  of  business  for  sums not yet due or being
diligently contested in good faith, if reserves or appropriate  provisions shall
have been made therefor;

                  (d) Liens  incurred  in the  ordinary  course of  business  in
connection  with  worker's  compensation  and  unemployment  insurance,   social
security  obligations,  assessments or government  charges which are not overdue
for more than sixty (60) days;

                  (e)  restrictions on the transfer of the Licenses or assets of
the Borrower or its  Restricted  Subsidiaries  imposed by any of the Licenses as
presently in effect or by the Communications Act and any regulations thereunder;

                  (f) easements, rights-of-way,  zoning restrictions,  licenses,
reservations or restrictions on use and other similar encumbrances on the use of
real property which do not materially interfere with the ordinary conduct of the
business of such Person or the use of such property;




                                      -16-
<PAGE>

                  (g) liens  arising by operation of law in favor of  purchasers
in connection with any asset sale permitted  hereunder;  provided that such lien
only encumbers the property being sold.

                  (h) Liens  reflected  by  Uniform  Commercial  Code  financing
statements filed in respect of Capitalized Lease Obligations  permitted pursuant
to  Section  7.1  hereof  and  true  leases  of  the  Borrower  or  any  of  its
Subsidiaries;

                  (i)  Liens to secure  performance  of  statutory  obligations,
surety or appeal bonds,  performance  bonds, bids, tenders or escrow deposits in
connection with permitted Acquisitions;

                  (j) judgment  Liens which do not result in an Event of Default
under Section 8.1 (h) hereof;

                  (k)  Liens  in  connection   with  escrow   deposits  made  in
connection with Acquisitions permitted hereunder; and

                  (l) additional Liens securing  Indebtedness  which does not in
the aggregate outstanding at any time exceed $500,000.

         "Person"  shall  mean an  individual,  corporation,  limited  liability
company,   association,   partnership,   joint  venture,  trust  or  estate,  an
unincorporated organization, a government or any agency or political subdivision
thereof, or any other entity.

         "Plan"  shall mean an  employee  benefit  plan  within  the  meaning of
Section  3(3) of  ERISA  or any  other  employee  benefit  plan  maintained  for
employees of any Person or any affiliate of such Person.

         "Pro Forma Debt  Service"  shall mean with  respect to the Borrower and
its Restricted  Subsidiaries,  on a consolidated basis, with respect to the next
succeeding complete twelve (12) month period following the calculation date, and
after giving effect to any Interest Hedge Agreements and LIBOR Advances, the sum
of the amount of all (i)  scheduled  payments of principal on  Indebtedness  for
Money  Borrowed  (determined  with respect to the Loans only, as the  difference
between the outstanding  principal  amount of the Loans on the calculation  date
and the amount the Commitment will be after the reductions  thereof set forth in
Section 2.5 hereof for such four calendar  quarter period have taken effect) for
such period,  (ii)  Interest  Expense for such period,  (iii) fees payable under
this Agreement for such period,  and (iv) other payments payable by such Persons
during such period in respect of  Indebtedness  for Money  Borrowed  (other than
voluntary  repayments under Section 2.7 hereof. For purposes of this definition,
where interest payments for the twelve (12) month 


                                      -17-
<PAGE>

period  immediately  succeeding  the  calculation  date are not  fixed by way of
Interest Hedge Agreements,  LIBOR Advances,  or otherwise for the entire period,
interest shall be calculated on such Indebtedness for Money Borrowed for periods
for  which  interest  payments  are not so fixed at the  lesser of (a) the LIBOR
Basis (based on the then current  adjustment  under Section 2.3(f) hereof) for a
LIBOR Advance  having an Interest  Period of six (6) months as determined on the
date of  calculation  and (b) the Base  Rate  Basis as in  effect on the date of
calculation; provided, however, that if such LIBOR Basis cannot be determined in
the  reasonable  opinion of the  Administrative  Agent,  such interest  shall be
calculated using the Base Rate Basis as then in effect.

         "Reportable  Event" shall mean,  with  respect to any Employee  Pension
Plan, an event described in Section 4043(b) of ERISA.

         "Request for Advance" shall mean a certificate designated as a "Request
for Advance,"  signed by an Authorized  Signatory of the Borrower  requesting an
Advance  hereunder,  which  shall  be in  substantially  the form of  Exhibit  G
attached  hereto,  and shall,  among other  things,  (i) specify the date of the
Advance,  which shall be a Business Day, the amount of the Advance,  the type of
Advance  (Eurodollar  or Base Rate),  and, with respect to LIBOR  Advances,  the
Interest Period selected by the Borrower, (ii) state that there shall not exist,
on the date of the requested Advance and after giving effect thereto, a Default,
as of the date of such Advance and after giving  effect  thereto,  and (iii) the
Applicable Margin then in effect.

         "Restricted  Payment"  shall mean any direct or indirect  distribution,
dividend  or other  payment to any Person  (other  than to the  Borrower  or any
Restricted  Subsidiary  of the  Borrower)  on account of any  general or limited
partnership  interest in, or shares of Capital Stock or other securities of, the
Borrower or any of its Restricted  Subsidiaries  (other than  dividends  payable
solely in stock of such Person and stock splits), including, without limitation,
any direct or indirect  distribution,  dividend  or other  payment to any Person
(other than to the Borrower or any  Restricted  Subsidiary  of the  Borrower) on
account of any warrants or other rights or options to acquire  shares of Capital
Stock of the Borrower or any of its Restricted Subsidiaries.

         "Restricted Subsidiary" shall mean any Subsidiary of the Borrower other
than an Unrestricted Subsidiary.

         "Security  Documents" shall mean the Borrower's Pledge  Agreement,  the
Subsidiary  Guaranty,  the Subsidiary Pledge Agreement,  the Borrower's Security
Agreement,  the Subsidiary Security Agreement,  the Parent Pledge Agreement, any
other agreement or instrument  providing  collateral for the Obligations whether
now or hereafter in existence,  and any filings,  instruments,  agreements,  and
documents related thereto or to this Agreement, 


                                      -18-
<PAGE>

and  providing  the  Administrative  Agent,  for the benefit of the Banks,  with
Collateral for the Obligations.

         "Security Interest" shall mean all Liens in favor of the Administrative
Agent,  for the  benefit of the  Banks,  created  hereunder  or under any of the
Security Documents to secure the Obligations.

         "Subsidiary"  shall mean, as applied to any Person, (a) any corporation
of which more than fifty  percent  (50%) of the  outstanding  stock  (other than
directors'  qualifying  shares) having ordinary voting power to elect a majority
of its board of directors, regardless of the existence at the time of a right of
the  holders  of any class or  classes  of  securities  of such  corporation  to
exercise such voting power by reason of the happening of any contingency, or any
partnership  of  which  more  than  fifty  percent  (50%)  of  the   outstanding
partnership  interests,  is at the time owned  directly  or  indirectly  by such
Person, or by one or more Subsidiaries of such Person, or by such Person and one
or more  Subsidiaries of such Person,  or (b) any other entity which is directly
or indirectly  controlled or capable of being  controlled by such Person,  or by
one or more  Subsidiaries  of such  Person,  or by such  Person  and one or more
Subsidiaries of such Person.

         "Subsidiary Guaranty" shall mean that certain Subsidiary Guaranty dated
as of even date herewith,  in favor of the  Administrative  Agent and the Banks,
given by each Restricted  Subsidiary of the Borrower,  substantially in the form
of Exhibit H hereof, and shall include any similar agreements  executed pursuant
to Section 5.14 hereof.

         "Subsidiary Pledge Agreement" shall mean that certain Subsidiary Pledge
Agreement dated as of even date herewith made by each  Restricted  Subsidiary of
the Borrower  having one or more of its own  Subsidiaries,  on the one hand,  in
favor of the Administrative Agent, on the other hand,  substantially in the form
of Exhibit I hereof, and shall include any similar agreements  executed pursuant
to Section 5.14 hereof.

         "Subsidiary  Security  Agreement"  shall mean that  certain  Subsidiary
Security Agreement dated as of even date herewith between each of the Borrower's
Restricted  Subsidiaries,  on the one hand, and the  Administrative  Agent,  (on
behalf of itself and the Banks), on the other hand, substantially in the form of
Exhibit J hereof, and shall include any similar agreements  executed pursuant to
Section 5.14 hereof.

         "Tax Sharing  Agreement" shall mean that certain Tax Sharing Agreement,
dated as of October 15, 1996, among Borrower, American Radio Systems and certain
other Subsidiaries of American Radio Systems.

         "Total  Debt"  shall  mean,   for  the  Borrower  and  its   Restricted
Subsidiaries  on  a  consolidated  basis  as  of  any  date,  the  sum  (without
duplication)  of (i) the  outstanding  


                                      -19-
<PAGE>

principal amount of the Loans,  (ii) the aggregate  amount of Capitalized  Lease
Obligations and Indebtedness for Money Borrowed,  and (iii) the aggregate amount
of all Guarantees.

         "Tower Operation Business" shall mean the ownership,  leasing and tower
management businesses of the Borrower and its Restricted Subsidiaries.

         "Unavailable Commitment" shall mean $150,000,000 of the Commitment.

         "Unrestricted  Subsidiary" shall mean any Subsidiary of the Borrower or
any joint venture (which may represent a minority interest) between the Borrower
and/or any Subsidiary of the Borrower and any other Person,  in each case, which
the  Borrower  has   heretofore   designated  or  hereafter   designates  as  an
Unrestricted  Subsidiary by written notice to the  Administrative  Agent and the
Banks prior to the formation or acquisition of such Subsidiary or joint venture.
Notwithstanding the foregoing,  no Restricted Subsidiary may be re-designated as
an Unrestricted  Subsidiary without the prior consent of the Majority Banks. The
Unrestricted  Subsidiaries as of the Agreement Date are as set forth on Schedule
2 attached hereto.

         "Unrestricted  Subsidiary  Distributions" shall mean the amount of cash
distributions  received  during such period by the Borrower  and its  Restricted
Subsidiaries from any Unrestricted Subsidiary (other than in connection with the
repayment of intercompany Indebtedness).

         "Use of  Proceeds  Letter"  shall  mean that  certain  Use of  Proceeds
Letter,  substantially in the form of Exhibit K attached hereto, to be delivered
to the Administrative Agent and the Banks on the date of any Advance hereunder.

         Each  definition  of an agreement in this Article 1 shall  include such
agreement as modified,  amended or supplemented  from time to time in accordance
herewith.


                                ARTICLE 2 Loans

         Section 2.1 The Loans. The Banks agree,  severally,  in accordance with
their respective  Commitment Ratios and not jointly,  upon the terms and subject
to the  conditions  of this  Agreement  and provided  there exists no Default or
Event of Default hereunder, to lend to the Borrower, prior to the Maturity Date,
an amount not at any one time  outstanding  to  exceed,  in the  aggregate,  the
Available  Commitment.  Subject to the terms and conditions  hereof and provided
there exists no Default or Event of Default hereunder, Advances hereunder may be
repaid and reborrowed from time to time on a revolving basis.




                                      -20-
<PAGE>

         Section 2.2 Manner of Borrowing and Disbursement.

                  (a) Choice of Interest Rate, Etc. Any Advance hereunder shall,
at the  option  of the  Borrower,  be made  as a Base  Rate  Advance  or a LIBOR
Advance;  provided,  however, that at such time as there shall have occurred and
be  continuing a Default  hereunder,  the  Borrower  shall not have the right to
receive  a LIBOR  Advance.  Any  notice  given  to the  Administrative  Agent in
connection   with  a  requested   Advance   hereunder  shall  be  given  to  the
Administrative  Agent  prior to 11:00  a.m.  (New  York  time) in order for such
Business Day to count toward the minimum number of Business Days required.

                   (b) Base Rate Advances.

                           (i)   Advances.   The   Borrower   shall   give   the
         Administrative Agent in the case of Base Rate Advances at least one (1)
         Business Day's irrevocable prior telephonic notice followed immediately
         by a  Request  for  Advance;  provided,  however,  that the  Borrower's
         failure to confirm  any  telephonic  notice  with a Request for Advance
         shall  not  invalidate  any  notice  so  given  if  acted  upon  by the
         Administrative  Agent.  Upon receipt of such notice from the  Borrower,
         the  Administrative  Agent shall promptly notify each Bank by telephone
         or telecopy of the contents thereof.

                           (ii)  Repayments and  Reborrowings.  The Borrower may
         repay or prepay a Base Rate Advance  without regard to its Payment Date
         and (A)  upon  at  least  one  (1)  Business  Day's  irrevocable  prior
         telephonic notice followed by written notice, reborrow all or a portion
         of the principal  amount  thereof as a Base Rate  Advance,  (B) upon at
         least three (3) Business  Days'  irrevocable  prior  telephonic  notice
         followed by written notice,  reborrow all or a portion of the principal
         thereof as one or more LIBOR  Advances,  or (C) not reborrow all or any
         portion  of such  Base  Rate  Advance.  On the  date  indicated  by the
         Borrower, such Base Rate Advance shall be so repaid and, as applicable,
         reborrowed. The failure to give timely notice hereunder with respect to
         the Payment Date of any Base Rate Advance shall be considered a request
         for a Base Rate Advance.

                   (c) LIBOR Advances.

                           (i) Advances. Upon request, the Administrative Agent,
         whose  determination  in absence of manifest error shall be conclusive,
         shall determine the available LIBOR Bases and shall notify the Borrower
         of such LIBOR  Bases to apply for the  applicable  LIBOR  advance.  The
         Borrower  shall  give  the  Administrative  Agent  in the case of LIBOR
         Advances at least three (3) Business Days' irrevocable prior telephonic
         notice  followed  immediately  by  a  Request  for  Advance;  provided,
         however,  that the Borrower's  failure to confirm any telephonic notice
         with a Request 


                                      -21-
<PAGE>

         for Advance shall not  invalidate  any notice so given if acted upon by
         the  Administrative  Agent.  Upon  receipt  of  such  notice  from  the
         Borrower,  the Administrative  Agent shall promptly notify each Bank by
         telephone or telecopy of the contents thereof.

                           (ii) Repayments and Reborrowings.  At least three (3)
         Business  Days prior to the Payment  Date for each LIBOR  Advance,  the
         Borrower shall give the Administrative Agent telephonic notice followed
         by written  notice  specifying  whether  all or a portion of such LIBOR
         Advance (A) is to be repaid and then  reborrowed in whole or in part as
         one or more LIBOR Advances,  (B) is to be repaid and then reborrowed in
         whole or in part as a Base Rate Advance, or (C) is to be repaid and not
         reborrowed. The failure to give such notice shall preclude the Borrower
         from  reborrowing  such Advance as a LIBOR  Advance on its Payment Date
         and shall be  considered a request for a Base Rate  Advance.  Upon such
         Payment Date such LIBOR Advance will, subject to the provisions hereof,
         be so repaid and, as applicable, reborrowed.

                  (d)  Notification  of Banks.  Upon  receipt  of a Request  for
Advance,  or a notice from the Borrower with respect to any outstanding  Advance
prior to the  Payment  Date for such  Advance,  the  Administrative  Agent shall
promptly  but no later  than the  close of  business  on the day of such  notice
notify each Bank by telephone or telecopy of the contents thereof and the amount
of such Bank's  portion of the  Advance.  Each Bank shall,  not later than 12:00
noon (New York time) on the date of borrowing  specified  in such  notice,  make
available to the Administrative  Agent at the Administrative  Agent's Office, or
at such account as the Administrative  Agent shall designate,  the amount of its
portion of any Advance which  represents an  additional  borrowing  hereunder in
immediately available funds.

                   (e) Disbursement.

                           (i) Prior to 2:00 p.m. (New York time) on the date of
         an Advance hereunder,  the Administrative  Agent shall,  subject to the
         satisfaction of the conditions set forth in Article 3 hereof,  disburse
         the amounts made available to the Administrative  Agent by the Banks in
         like funds by (A)  transferring  the amounts so made  available by wire
         transfer pursuant to the Borrower's instructions, or (B) in the absence
         of such  instructions,  crediting the amounts so made  available to the
         account of the Borrower maintained with the Administrative Agent.

                           (ii)  Unless  the  Administrative  Agent  shall  have
         received  notice from a Bank prior to 12:00 noon (New York time) on the
         date of any  Advance  that  such Bank  will not make  available  to the
         Administrative  Agent such Bank's ratable portion of such Advance,  the
         Administrative  Agent may  assume  that such Bank has 


                                      -22-
<PAGE>

         made or will make such portion available to the Administrative Agent on
         the date of such Advance and the  Administrative  Agent may in its sole
         discretion and in reliance upon such assumption,  make available to the
         Borrower on such date a corresponding  amount. If and to the extent the
         Bank does not make such ratable portion available to the Administrative
         Agent, such Bank agrees to repay to the Administrative  Agent on demand
         such corresponding  amount together with interest thereon, for each day
         from the date such amount is made  available to the Borrower  until the
         date such amount is repaid to the Administrative  Agent, at the Federal
         Funds Rate.

                           (iii) If such Bank shall repay to the  Administrative
         Agent such corresponding amount, such amount so repaid shall constitute
         such Bank's  portion of the  applicable  Advance  for  purposes of this
         Agreement.  If such  Bank  does not  repay  such  corresponding  amount
         immediately  upon  the  Administrative  Agent's  demand  therefor,  the
         Administrative  Agent shall notify the Borrower and the Borrower  shall
         immediately pay such corresponding amount to the Administrative  Agent,
         with  interest  at the Federal  Funds Rate.  The failure of any Bank to
         fund its portion of any Advance shall not relieve any other Bank of its
         obligation,  if any,  hereunder to fund its  respective  portion of the
         Advance on the date of such borrowing, but no Bank shall be responsible
         for any such failure of any other Bank.

                           (iv) In the event that, at any time when the Borrower
         is not in Default and has otherwise satisfied each of the conditions in
         Section 3.2 hereof,  a Bank for any reason fails or refuses to fund its
         portion of an Advance and such failure  shall  continue for a period in
         excess of thirty  (30)  days,  then,  until  such time as such Bank has
         funded its  portion  of such  Advance  (which  late  funding  shall not
         absolve such Bank from any liability it may have to the  Borrower),  or
         all  other  Banks  have  received  payment  in full  from the  Borrower
         (whether by repayment or  prepayment) or otherwise of the principal and
         interest due in respect of such Advance,  such  non-funding  Bank shall
         not have the right (A) to vote  regarding  any issue on which voting is
         required or advisable  under this Agreement or any other Loan Document,
         and  such  Bank's  portion  of  the  Loans  shall  not  be  counted  as
         outstanding for purposes of determining "Majority Banks" hereunder, and
         (B) to  receive  payments  of  principal,  interest  or fees  from  the
         Borrower, the Administrative Agent or the other Banks in respect of its
         portion of the Loans.

         Section 2.3 Interest.

                  (a) On Base Rate Advances.  Interest on each Base Rate Advance
shall be computed on the basis of a year of 365/366  days for the actual  number
of days elapsed and shall be payable at the Base Rate Basis for such Advance, in
arrears on the  applicable  Payment  Date.  Interest on Base Rate  Advances then
outstanding shall also be due and payable on the Maturity Date.




                                      -23-
<PAGE>

                  (b) On LIBOR Advances. Interest on each LIBOR Advance shall be
computed on the basis of a 360-day  year for the actual  number of days  elapsed
and shall be  payable  at the LIBOR  Basis for such  Advance,  in arrears on the
applicable  Payment Date,  and, in addition,  if the Interest Period for a LIBOR
Advance  exceeds three (3) months,  interest on such LIBOR Advance shall also be
due and payable in arrears on every three-month  anniversary of the beginning of
such Interest Period.  Interest on LIBOR Advances then outstanding shall also be
due and payable on the Maturity Date.

                  (c) Interest if no Notice of Selection of Interest Rate Basis.
If the Borrower  fails to give the  Administrative  Agent  timely  notice of its
selection  of a LIBOR  Basis,  or if for any reason a  determination  of a LIBOR
Basis for any Advance is not timely  concluded,  the Base Rate Basis shall apply
to such Advance.

                  (d) Interest Upon Default.  Immediately upon the occurrence of
an Event of Default  hereunder,  the outstanding  principal balance of the Loans
shall bear  interest  at the Default  Rate.  Such  interest  shall be payable on
demand by the Majority Banks and shall accrue until the earlier of (i) waiver or
cure of the  applicable  Event of Default,  (ii) agreement by the Majority Banks
(or, if applicable to the underlying Event of Default, the Banks) to rescind the
charging  of  interest  at the  Default  Rate,  or (iii)  payment in full of the
Obligations.

                  (e) LIBOR Contracts.  At no time may the number of outstanding
LIBOR Advances exceed six (6).

                  (f)  Applicable  Margin.  With  respect  to any  Advance,  the
Applicable  Margin shall be as set forth in a certificate of the chief financial
officer of the  Borrower  delivered to the  Administrative  Agent based upon the
Applicable  Margin  Ratio  for the most  recent  fiscal  quarter  end for  which
financial  statements are furnished by the Borrower to the Administrative  Agent
and each Bank for the fiscal quarter most recently ended as follows:




                                      -24-
<PAGE>
<TABLE>
<CAPTION>

                Applicable Margin Ratio                                   Base Rate               LIBOR Advance
                                                                     Advance Applicable            Applicable
                                                                           Margin                    Margin

<S>                                                                         <C>                     <C>   
A.   Greater than or equal to 5.50:1                                          1.000%                  2.250%

B.   Greater than or equal to 5.00:1, but less than 5.50: 1                   0.875%                  2.125%

C.   Greater than or equal to 4.50:1, but less than 5.00:1                    0.625%                  1.875%

D.   Greater than or equal to 4.00:1, but less than 4.50:1                    0.375%                  1.625%

E.   Greater than 3.50: 1, but less than 4.00:1                               0.000%                  1.250%

F.   Less than 3.50:1                                                         0.000%                  1.000%
</TABLE>

Changes to the  Applicable  Margin  shall be  effective  (i) with  respect to an
increase in the Applicable Margin, as of the second (2nd) Business Day after the
day on which the  financial  statements  are  required  to be  delivered  to the
Administrative  Agent and the Banks  pursuant  to  Section  6.1 or  Section  6.2
hereof, as the case may be; provided,  however, if such financial statements are
not  delivered to the  Administrative  Agent and the Banks on or before the date
specified  in such  Section,  such  increase  shall be  effective as of the date
specified  in such Section for delivery of the  financial  statements,  and (ii)
with respect to a decrease in the Applicable  Margin, as of the later of (A) the
second (2nd) Business Day after the day on which such  financial  statements are
required to be delivered  pursuant to Section 6.1 or Section 6.2 hereof,  as the
case may be, and (B) the date on which such  financial  statements  are actually
delivered to the  Administrative  Agent and the Banks. The Applicable  Margin on
the Agreement Date shall be based on the Borrower's  financial  statements  with
respect to June 30, 1997 and the Total Debt as of the Agreement Date.

         Upon the occurrence and during the  continuance of an Event of Default,
the  Applicable  Margins shall not be subject to downward  adjustment  and shall
automatically  revert to the Applicable Margins set forth in part A of the above
table until such time as such Event of Default is cured or waived.

         Section 2.4 Commitment Fees.

                  (a) Unavailable Commitment.  Commencing on the Agreement Date,
and continuing  until the earlier to occur of (i) the date of the effective date
of the  Commitment  Increase  (if any) and (ii)  the  first  anniversary  of the
Agreement Date, the Borrower agrees to pay to the  Administrative  Agent for the
account  of each  of the  Banks,  in  accordance  with  such  Bank's  respective
Commitment  Ratio, a commitment fee on the amount of the 


                                      -25-
<PAGE>

Unavailable  Commitment  at a rate of  one-eighth  of one percent  (0.125%)  per
annum,  which fee shall be computed  on the basis of a year of 365/366  days for
the actual number of days elapsed,  shall be payable quarterly in arrears on the
last Business Day of each  calendar  quarter and on the earliest to occur of the
above dates, and shall be fully earned when due and non-refundable when paid.

                  (b) Available Commitment. Commencing on the Agreement Date and
of all times thereafter,  the Borrower agrees to pay to the Administrative Agent
for the account of each of the Banks in accordance  with such Bank's  respective
Commitment  Ratio, a commitment fee on the aggregate  unborrowed  balance of the
Commitment (less, if applicable,  the Unavailable  Commitment) for each day from
the  date of the  Agreement  Date  until  the  Maturity  Date,  at a rate of (i)
one-half of one percent  (0.500%) per annum when the Applicable  Margin Ratio is
greater than or equal to 4.00: 1; and (ii) three-eighths of one percent (0.375%)
per annum when the Applicable Margin Ratio is less than 4.00: 1. Such commitment
fee shall be  computed  on the basis of a year of  365/366  days for the  actual
number of days  elapsed,  shall be  payable  quarterly  in  arrears  on the last
Business Day of each  calendar  quarter,  and shall be fully earned when due and
non-refundable  when paid. A final  payment of any  commitment  fee then payable
shall also be due and payable on the Maturity Date.

         Section 2.5 Mandatory Commitment Reductions

                  (a) Scheduled Reductions. Commencing on September 30, 2000 and
at the end of each calendar quarter  thereafter,  the Existing  Commitment as of
September 29, 2000 shall be automatically  and permanently  reduced as set forth
below (which  reductions are in addition to those set forth in Sections  2.5(b),
2.5(c), 2.5(d) and 2.6 hereof):




                                      -26-
<PAGE>

<TABLE>
<CAPTION>
                                                                            Quarterly Percentage of Reduction
                                                                                  of Existing Commitment
      Dates of Existing Commitment Reduction                                       As Of September 29, 2000
      --------------------------------------                              ---------------------------------

<S>                                                                                        <C>   
September 30, 2000 and December 31, 2000                                                   3.750%

March 3 1, 2001, June 30, 2001,
September 30, 2001 and December 31, 2001                                                   3.125%

March 31, 2002, June 30, 2002,
September 30, 2002 and December 31, 2002                                                   3.750%

March 31, 2003, June 30, 2003,
September 30, 2003 and December 31, 2003                                                   5.000%

March 31, 2004, June 30, 2004,
September 30, 2004 and December 31, 2004                                                   5.625%

March 31, 2005                                                                             7.500%
</TABLE>

The Borrower  shall make a repayment  of the Loans  outstanding,  together  with
accrued interest  thereon,  on or before the effective date of each reduction in
the Existing  Commitment  under this  Section  2.5(a),  such that the  aggregate
principal  amount of the  Loans  outstanding  at no time  exceeds  the  Existing
Commitment as so reduced.  Any remaining unpaid principal and interest under the
Existing  Commitment  shall be due and payable in full on the Maturity Date, and
the Existing Commitment shall thereupon terminate.

                  (b) Reduction From Excess Cash Flow. On April 15, 2001, and on
each  April 15  thereafter  during  the  term of this  Agreement,  the  Existing
Commitment  shall be  permanently  reduced by an amount  equal to fifty  percent
(50%) of  Excess  Cash  Flow  for the  fiscal  year  immediately  preceding  the
calculation date. Reductions to the Existing Commitment under this Section shall
be applied to the reductions set forth in Section 2.5(a) hereof in inverse order
of the reductions set forth therein.

                  (c) Reduction From Permitted  Asset Sales. On the Business Day
following  the  date  of  receipt  by the  Borrower  or  any  of its  Restricted
Subsidiaries of the Net Proceeds of any asset sale permitted pursuant to Section
7.4 hereof,  the Existing  Commitment  shall be  automatically  and  permanently
reduced by an amount equal to such Net  Proceeds;  provided,  however,  that the
Existing  Commitment  shall not be required  to be reduced by such Net  Proceeds
until the  amount of such  unapplied  Net  Proceeds  exceeds  $1,000,000  in the
aggregate during the term hereof; provided,  further, however, that the Borrower
may notify the Administrative Agent in writing that it intends to use any or all
of 


                                      -27-
<PAGE>

such Net Proceeds to acquire  fixed or capital  assets  permitted by Section 7.6
hereof  within six (6) months of the date of  receipt of such Net  Proceeds,  in
which case, the reduction in the Existing Commitment up to the amount of the Net
Proceeds intended to be used which is otherwise  required by this Section 2.5(c)
need  not be  made,  but if all or part of such  Net  Proceeds  are not  used or
irrevocably  committed to be used within such six (6)-month period, the Existing
Commitment shall be permanently  reduced by an amount equal to such Net Proceeds
on the  earlier  of (i) the first day  following  the end of such six  (6)-month
period and (ii) the date on which the Borrower has  reasonably  determined  that
such Net Proceeds  shall not be so used.  Reductions to the Existing  Commitment
under  this  Section  shall be applied  to the  reductions  set forth in Section
2.5(a) hereof in inverse order of the reductions set forth therein.

                  (d) Reduction From Sale of Capital Stock and Debt Instruments.
On the  Business  Day  following  the date of receipt by the Borrower of the net
proceeds of any sale its Capital Stock or debt  instruments or other  securities
(other than an amount not to exceed $2,000,000 in the aggregate from the sale of
securities in connection  with any employee  stock option plan of the Borrower),
the Existing  Commitment  shall  automatically  and permanently be reduced by an
amount equal (i) 100% of such net  proceeds to the extent the Leverage  Ratio is
greater  than or equal to 4.0: 1; or (ii) 50% of such net proceeds to the extent
the Leverage  Ratio is less than 4.0: 1;  provided,  however,  the provisions of
this  Section  2.5(d) shall not apply to equity  contributions  by the Parent or
American  Radio  Systems  which are made with the proceeds to  Indebtedness  for
Money Borrowed  issued in accordance with Section 8.1(p) hereof and which do not
exceed $50,000,000 in the aggregate. Reductions to the Existing Commitment under
this  Section  shall be applied to the  reductions  set forth in Section  2.5(a)
hereof in inverse order of the reductions set forth therein.

         Section 2.6 Voluntary  Commitment  Reductions.  The Borrower shall have
the right,  at any time and from time to time after the Agreement Date and prior
to the  Maturity  Date,  upon at least three (3)  Business  Days' prior  written
notice to the  Administrative  Agent,  without premium or penalty,  to cancel or
reduce  permanently all or a portion of the Existing  Commitment,  on a pro rata
basis among the Banks, provided,  however, that any such partial reduction shall
be made in an amount not less than  $5,000,000 and in integral  multiples of not
less than  $1,000,000.  As of the date of cancellation or reduction set forth in
such notice, the Existing  Commitment shall be permanently reduced to the amount
stated in the Borrower's notice for all purposes herein,  and the Borrower shall
pay to the Administrative Agent for the Banks the amount necessary to reduce the
principal amount of the Loans then outstanding under the Existing  Commitment to
not more than the amount of the Existing Commitment as so reduced, together with
accrued  interest on the amount so prepaid and commitment  fees accrued  through
the date of the reduction with respect to the amount reduced.  Reductions in the
Existing  Commitment  pursuant to this Section  shall be applied pro rata to the
then remaining reductions set forth in Section 2.5(a) hereof.

                                       -28-
<PAGE>


         Section 2.7 Prepayments and Repayments.

                  (a) Prepayment.  The principal amount of any Base Rate Advance
may be  prepaid  in full or ratably  in part at any time,  without  penalty  and
without  regard to the Payment  Date for such  Advance.  LIBOR  Advances  may be
prepaid  prior to the  applicable  Payment Date,  upon three (3) Business  Days'
prior written  notice to the  Administrative  Agent,  provided that the Borrower
shall  reimburse  the  Banks  and the  Administrative  Agent,  on  demand by the
applicable  Bank  or the  Administrative  Agent,  for  any  loss  or  reasonable
out-of-pocket  expense  incurred  by any  Bank or the  Administrative  Agent  in
connection  with such  prepayment,  as set forth in  Section  2.10  hereof.  Any
prepayment  hereunder  shall be in  amounts  of not less  than  $500,000  and in
integral multiples of $100,000.

                   (b) Repayments.

                           (i) Loans in Excess of  Commitment.  If, at any time,
                  the  amount of the Loans  then  outstanding  shall  exceed the
                  Available  Commitment,  the Borrower  shall,  on such date and
                  subject to Sections 2.10 and 2.11 hereof,  make a repayment of
                  the  principal  amount of the Loans in an amount equal to such
                  excess,  together  with any  accrued  interest  and fees  with
                  respect thereto.
                                    
                           (ii) From Excess Cash Flow. On April 15, 2000, and on
                  each April 15  thereafter  during the term of this  Agreement,
                  the  Borrower  shall  make  a  repayment  of  the  Loans  then
                  outstanding  in an amount equal to fifty  percent (50%) of the
                  Excess Cash Flow for the fiscal year immediately preceding the
                  calculation date.
                                   
                           (iii) From Permitted Asset Sales. On the Business Day
                  following  the date of receipt by the  Borrower  or any of its
                  Restricted  Subsidiaries of the Net Proceeds of any asset sale
                  permitted  pursuant to Section  7.4 hereof,  and to the extent
                  that  the   Borrower  is  required  to  reduce  the   Existing
                  Commitment  pursuant to Section  2.5(c)  hereof,  the Borrower
                  shall make a repayment  of the Loans by an amount equal to the
                  amount of such reduction.                              

                           (iv) From Capital Stock and Debt Instruments.  On the
                  Business Day  following the receipt by the Borrower of the Net
                  Proceeds of any sale of its Capital Stock or debt  instruments
                  or other  securities,  and to the extent that the  Borrower is
                  required to reduce the Existing Commitment pursuant to Section
                  2.5(d)  hereof,  the  Borrower  shall make a repayment  of the
                  Loans by an amount equal to the amount of such reduction.
                                    
                           (v) Maturity  Date. In addition to the  foregoing,  a
                  final payment of all Obligations then outstanding shall be due
                  and payable on the Maturity Date.

                                       -29-
<PAGE>

                                  

         Section 2.8 Notes; Loan Accounts.

                   (a) The Loans shall be repayable in accordance with the terms
and  provisions  set forth herein and shall be evidenced by the Notes.  One Note
shall be payable  to the order of each  Bank,  in  accordance  with such  Bank's
respective  Commitment  Ratio.  The Notes shall be issued by the Borrower to the
Banks  and  shall  be duly  executed  and  delivered  by one or more  Authorized
Signatories.

                   (b) Each Bank may open and  maintain on its books in the name
of the  Borrower a loan  account  with  respect to its  portion of the Loans and
interest  thereon.  Each Bank which opens such a loan  account  shall debit such
loan account for the principal  amount of its portion of each Advance made by it
and  accrued  interest  thereon,  and shall  credit  such loan  account for each
payment on account of  principal  of or interest on its Loans.  The records of a
Bank with  respect to the loan  account  maintained  by it shall be prima  facie
evidence  of its  portion  of the  Loans and  accrued  interest  thereon  absent
manifest  error,  but the failure of any Bank to make any such  notations or any
error or mistake in such  notations  shall not affect the  Borrower's  repayment
obligations with respect to such Loans.

         Section 2.9 Manner of Payment.

                  (a) Each payment (including any prepayment) by the Borrower on
account of the  principal of or interest on the Loans,  commitment  fees and any
other amount owed to the Banks or the Administrative  Agent or any of them under
this  Agreement  or the Notes  shall be made not later than 1:00 p.m.  (New York
time)  on  the  date   specified  for  payment  under  this   Agreement  to  the
Administrative  Agent at the  Administrative  Agent's Office, for the account of
the Banks or the  Administrative  Agent,  as the case may be, in lawful money of
the  United  States of America  in  immediately  available  funds.  Any  payment
received by the  Administrative  Agent after 1:00 p.m.  (New York time) shall be
deemed received on the next Business Day. Receipt by the Administrative Agent of
any payment  intended for any Bank or Banks  hereunder  prior to 1:00 p.m.  (New
York time) on any  Business  Day shall be deemed to  constitute  receipt by such
Bank or Banks on such  Business Day. In the case of a payment for the account of
a Bank, the Administrative  Agent will promptly,  but no later than the close of
business on the date such payment is deemed received,  thereafter distribute the
amount so received in like funds to such Bank. If the Administrative Agent shall
not  have  received  any  payment  from  the  Borrower  as  and  when  due,  the
Administrative  Agent will promptly notify the Banks  accordingly.  In the event
that the  Administrative  Agent shall fail to make  distribution  to any Bank as
required  under this Section 2.9,  the  Administrative  Agent agrees to pay such
Bank interest from the date such payment was due until paid at the Federal Funds
Rate.

                                       -30-
<PAGE>


                   (b) The Borrower agrees to pay principal,  interest, fees and
all  other  amounts  due  hereunder  or  under  the  Notes  without  set-off  or
counterclaim or any deduction whatsoever.

                  (c)  Prior to the  declaration  of an Event of  Default  under
Section 8.2 hereof,  if some but less than all amounts due from the Borrower are
received  by the  Administrative  Agent  with  respect to the  Obligations,  the
Administrative  Agent shall  distribute  such amounts in the following  order of
priority, all on a pro rata basis to the Banks: (i) to the payment on a pro rata
basis of any fees or expenses then due and payable to the  Administrative  Agent
or the  Banks,  or any of them;  (ii) to the  payment of  interest  then due and
payable on the Loans;  (iii) to the payment of all other  amounts not  otherwise
referred to in this  Section  2.9(c) then due and payable to the  Administrative
Agent or the Banks,  or any of them,  hereunder  or under the Notes or any other
Loan Document;  and (iv) to the payment of principal then due and payable on the
Loans.

                   (d) Subject to any contrary  provisions in the  definition of
Interest  Period,  if any payment under this  Agreement or any of the other Loan
Documents is specified to be made on a day which is not a Business Day, it shall
be made on the next Business Day, and such  extension of time shall in such case
be included in computing  interest  and fees,  if any, in  connection  with such
payment.

         Section 2.10 Reimbursement.

                  (a)  Whenever  any Bank  shall  sustain or incur any losses or
reasonable out-of-pocket expenses in connection with (i) failure by the Borrower
to borrow any LIBOR Advance after having given notice of its intention to borrow
in  accordance  with  Section 2.2 hereof  (whether  by reason of the  Borrower's
election  not to proceed or the  non-fulfillment  of any of the  conditions  set
forth in Article  3), or (ii)  prepayment  (or  failure to prepay  after  giving
notice  thereof) of any LIBOR  Advance in whole or in part for any  reason,  the
Borrower  agrees  to pay to such  Bank,  upon  such  Bank's  demand,  an  amount
sufficient  to  compensate  such  Bank for all  such  losses  and  out-of-pocket
expenses.  Such Bank's good faith  determination of the amount of such losses or
out-of-pocket  expenses, as set forth in writing and accompanied by calculations
in  reasonable  detail   demonstrating  the  basis  for  its  demand,  shall  be
presumptively correct absent manifest error.

                  (b) Losses subject to  reimbursement  hereunder shall include,
without  limiting  the  generality  of the  foregoing,  lost  margins,  expenses
incurred by any Bank or any  participant  of such Bank  permitted  hereunder  in
connection with the re-employment of funds prepaid,  paid, repaid, not borrowed,
or not paid,  as the case may be, and will be payable  whether the Maturity Date
is changed by virtue of an amendment  hereto  (unless such  amendment  expressly
waives such payment) or as a result of acceleration of the Obligations.

                                       -31-
<PAGE>


         Section 2.11 Pro Rata Treatment.

                  (a) Advances. Each Advance from the Banks hereunder,  shall be
made pro rata on the basis of the respective Commitment Ratios of the Banks.

                  (b) Payments.  Each payment and prepayment of principal of the
Loans,  and,  except as provided in Section  2.2(e) and Article 10 hereof,  each
payment of  interest  on the  Loans,  shall be made to the Banks pro rata on the
basis of their respective unpaid principal  amounts  outstanding under the Notes
immediately  prior to such payment or  prepayment.  If any Bank shall obtain any
payment (whether  involuntary,  through the exercise of any right of set-off, or
otherwise)  on account of the Loans in excess of its ratable  share of the Loans
under its Commitment  Ratio,  such Bank shall forthwith  purchase from the other
Banks such  participations  in the portion of the Loans made by them as shall be
necessary to cause such purchasing Bank to share the excess payment ratably with
each of them;  provided,  however,  that if all or any  portion  of such  excess
payment is thereafter  recovered from such  purchasing  Bank, such purchase from
each Bank shall be rescinded  and such Bank shall repay to the  purchasing  Bank
the purchase price to the extent of such recovery.  The Borrower agrees that any
Bank so  purchasing a  participation  from another Bank pursuant to this Section
2.11(b) may, to the fullest extent permitted by law,  exercise all its rights of
payment  (including the right of set-off) with respect to such  participation as
fully as if such Bank were the direct  creditor of the Borrower in the amount of
such participation.

         Section 2.12 Capital Adequacy.  If after the date hereof,  the adoption
of any  Applicable  Law regarding the capital  adequacy of banks or bank holding
companies,  or any change in Applicable Law (whether adopted before or after the
Agreement Date) or any change in the interpretation or administration thereof by
any governmental  authority,  central bank or comparable agency charged with the
interpretation  or  administration  thereof,  or compliance by such Bank (or the
bank holding company of such Bank) with any directive regarding capital adequacy
(whether  or not  having the force of law) of any such  governmental  authority,
central bank or comparable  agency, has or would have the effect of reducing the
rate of  return  on any  Bank's  capital  as a  consequence  of its  obligations
hereunder  with  respect to the Loans and the  Commitment  to a level below that
which it could have achieved but for such adoption, change or compliance (taking
into  consideration  such  Bank's  policies  with  respect to  capital  adequacy
immediately  before such  adoption,  change or compliance and assuming that such
Bank's (or the bank  holding  company of such Bank)  capital was fully  utilized
prior to such adoption,  change or compliance) by an amount reasonably deemed by
such Bank to be material,  then,  upon demand by such Bank,  the Borrower  shall
promptly  pay to such Bank such  additional  amounts as shall be  sufficient  to
compensate  such Bank for such reduced  return,  together  with interest on such
amount  from the  fourth  (4th)  Business  Day  after  the date of demand or the
Maturity Date, as applicable, until payment in full thereof at the Default Rate.
A  certificate  of such Bank setting forth the amount to be paid to such Bank by
the  Borrower  as a  result  of any  event  referred  to in this  

                                       -32-
<PAGE>

paragraph  and   supporting   calculations   in   reasonable   detail  shall  be
presumptively correct absent manifest error.

         Section 2.13 Bank Tax Forms.  On or prior to the Agreement  Date and on
or prior to the first Business Day of each calendar year  thereafter,  each Bank
which is organized in a jurisdiction  other than the United States shall provide
each of the  Administrative  Agent and the  Borrower  with a  properly  executed
originals  of  Forms  4224 or 1001 (or any  successor  form)  prescribed  by the
Internal Revenue Service or other documents satisfactory to the Borrower and the
Administrative  Agent, and properly  executed Internal Revenue Service Forms W-8
or W-9, as the case may be, certifying (i) as to such Bank's status for purposes
of determining  exemption from United States  withholding  taxes with respect to
all payments to be made to such Bank  hereunder and under the Notes or (ii) that
all payments to be made to such Bank  hereunder  and under the Notes are subject
to such taxes at a rate reduced to zero by an applicable  tax treaty.  Each such
Bank agrees to provide the Administrative  Agent and the Borrower with new forms
prescribed by the Internal  Revenue  Service upon the expiration or obsolescence
of any previously delivered form, or after the occurrence of any event requiring
a change in the most recent forms  delivered by it to the  Administrative  Agent
and the Borrower.


                         ARTICLE 3 Conditions Precedent

         Section 3.1 Conditions Precedent to Effectiveness of this Amendment and
Restatement.  The  effectiveness  of this amendment and restatement to the Prior
Loan Agreement is subject to the prior or contemporaneous fulfillment of each of
the following conditions:
                                  
                  (a) The Administrative Agent and the Banks shall have received
each of the following:

                           (i) this Agreement duly executed;

                           (ii) the loan certificate of the Borrower dated as of
                  the Agreement Date, in substantially  the form attached hereto
                  as Exhibit L,  including  a  certificate  of  incumbency  with
                  respect to each Authorized Signatory of such Person,  together
                  with the  following  items:  (A) a true,  complete and correct
                  copy of the  Certificate of  Incorporation  and By-laws of the
                  Borrower as in effect on the Agreement Date, (B)  certificates
                  of good  standing for the Borrower  issued by the Secretary of
                  State or similar state official for the state of incorporation
                  of the  Borrower  and for each state in which the  Borrower is
                  required to qualify to do business,  (C) a true,  complete and
                  correct  copy of the  corporate  resolutions  of the  Borrower
                  authorizing the Borrower to execute,  deliver and perform this
                  Agreement and the other Loan Documents, and (D)

                                       -33-
<PAGE>

                  a  true,  complete  and  correct  copy  of  any  shareholders'
                  agreements  or voting trust  agreements in effect with respect
                  to the stock of the Borrower;

                           (iii) duly executed Notes;

                           (iv) duly executed Security Documents;

                           (v)  copies  of  insurance  binders  or  certificates
                  covering  the  assets  of  the  Borrower  and  its  Restricted
                  Subsidiaries,   and  otherwise  meeting  the  requirements  of
                  Section 5.5  hereof,  together  with copies of the  underlying
                  insurance policies;

                           (vi) legal  opinion  of  Sullivan  &  Worcester  LLP,
                  counsel  to the  Borrower;  addressed  to  each  Bank  and the
                  Administrative Agent and dated as of the Agreement Date;

                           (vii)  duly   executed   Certificates   of  Financial
                  Condition for the Borrower and its Restricted  Subsidiaries on
                  a consolidated  and  consolidating  basis,  given by the chief
                  financial officer of the Borrower;

                           (viii) copies of the most recent quarterly  financial
                  statements  of the  Borrower and its  Restricted  Subsidiaries
                  provided to each Bank and each Administrative Agent, certified
                  by the chief financial officer of the Borrower;

                           (ix) duly executed  Master  Assignment and Assumption
                  Agreement dated as of the Agreement Date,  among the Banks and
                  Signet Bank,  N.A. in form and substance  satisfactory  to the
                  Banks; and

                           (x)all  such other  documents  as the  Administrative
                  Agent may  reasonably  request,  certified  by an  appropriate
                  governmental   official  or  an  Authorized  Signatory  if  so
                  requested.

                   (b)  The  Administrative  Agent  and  the  Banks  shall  have
received  evidence  satisfactory  to them  that  all  Necessary  Authorizations,
including all  necessary  consents to the closing of this  Agreement,  have been
obtained  or made,  are in full  force and  effect  and are not  subject  to any
pending  or,  to  the  knowledge  of  the  Borrower,   threatened   reversal  or
cancellation,  and the Administrative  Agent and the Banks shall have received a
certificate of an Authorized Signatory so stating.

                   (c) The Borrower  shall certify to the  Administrative  Agent
and the Banks  that each of the  representations  and  warranties  in  Article 4
hereof are true and correct in all material  respects as of the  Agreement  Date
and that no Default or Event of Default then exists or is continuing.


                                       -34-
<PAGE>

                   (d) The Borrower shall have paid to the Administrative  Agent
for the  account  of each  Bank  the  facility  fees set  forth in those  letter
agreements dated the Agreement Date in favor of each Bank.

                   (e) The  Administrative  Agent shall have received  copies of
executed  asset  purchase  agreements  for certain  acquistions  from Diablo and
Micronet for an aggregate purchase price of not greater than $120,000,000 and in
form and substance satisfactory to the Banks.

                   (f) The  Administrative  Agent shall have  received  evidence
reasonably  satisfactory  to it that no real  property  owned by the Borrower is
located in a Federal or state  designated  flood zone or, to the extent that any
such real  property  is  located in a Federal or state  designated  flood  zone,
evidence  satisfactory  to it that such real  property is  sufficiently  insured
against flood related losses.

         Section 3.2 Conditions Precedent to Each Advance. The obligation of the
Banks to make each  Advance  on or after the  Agreement  Date is  subject to the
fulfillment  of  each  of  the  following  conditions  immediately  prior  to or
contemporaneously with such Advance:
                                   
                  (a) All of the  representations and warranties of the Borrower
under  this  Agreement  and  the  other  Loan  Documents   (including,   without
limitation,  all  representations  and warranties with respect to the Borrower's
Restricted Subsidiaries), which, pursuant to Section 4.2 hereof, are made at and
as of the time of such  Advance,  shall be true and  correct at such time in all
material respects, both before and after giving effect to the application of the
proceeds of such Advance,  and after giving effect to any updates to information
provided to the Banks in accordance with the terms of such  representations  and
warranties, and no Default hereunder shall then exist or be caused thereby;

                   (b) With respect to Advances which, if funded, would increase
the   aggregate   principal   amount  of  Loans   outstanding   hereunder,   the
Administrative Agent shall have received a duly executed Request for Advance;

                   (c)  The  Administrative  Agent  and  the  Banks  shall  have
received all such other certificates,  reports, statements,  opinions of counsel
(if such Advance is in connection with an Acquisition) or other documents as the
Administrative Agent or any Bank may reasonably request;

                   (d) With respect to any Advance  relating to any  Acquisition
or  the  formation  of  any  Subsidiary  which  is  permitted   hereunder,   the
Administrative  Agent and the Banks  shall  have  received  such  documents  and
instruments  relating  to such  Acquisition  or 

                                       -35-
<PAGE>


formation of a new Restricted Subsidiary as are described in Section 5.14 hereof
or otherwise required herein.

                    ARTICLE 4 Representations and Warranties

         Section 4.1 Representations and Warranties. The Borrower hereby agrees,
represents and warrants, upon the Agreement Date, in favor of the Administrative
Agent and each Bank that:                                   

                  (a)  Organization;   Ownership;  Power;   Qualification.   The
Borrower is a corporation duly organized,  validly existing and in good standing
under the laws of the State of Delaware.  The Borrower has the  corporate  power
and  authority to own its  properties  and to carry on its business as now being
and as  proposed  hereafter  to be  conducted.  Except as set forth on  Schedule
4.l(a)  attached  hereto,  each  Restricted  Subsidiary  of  the  Borrower  is a
corporation duly organized, validly existing and in good standing under the laws
of the state of its  incorporation  and has the corporate power and authority to
own its  properties  and to carry on its  business  as now being and as proposed
hereafter to be conducted.  The Borrower and each of its Restricted Subsidiaries
are duly  qualified,  in good  standing  and  authorized  to do business in each
jurisdiction in which the character of their respective properties or the nature
of their respective  businesses  requires such  qualification or  authorization,
except where failure to be so qualified, in the aggregate,  could not reasonably
be expected to have a Material Adverse Effect.

                  (b)  Authorization;   Enforceability.  The  Borrower  has  the
corporate power and has taken all necessary  corporate action to authorize it to
borrow hereunder, to execute, deliver and perform this Agreement and each of the
other Loan Documents to which it is a party in accordance with their  respective
terms, and to consummate the transactions  contemplated hereby and thereby. This
Agreement  has been duly executed and delivered by the Borrower and is, and each
of the other Loan  Documents to which the  Borrower is party is, a legal,  valid
and binding  obligation  of the  Borrower  enforceable  against the  Borrower in
accordance with its terms, subject, as to enforcement of remedies, to applicable
bankruptcy,  insolvency, fraudulent conveyance,  reorganization,  moratorium and
similar laws affecting creditors' rights and remedies generally, and subject, as
to enforceability, to general principles of equity.

                  (c)   Subsidiaries:    Authorization;    Enforceability.   The
Borrower's  Restricted  Subsidiaries  and the  Borrower's  direct  and  indirect
ownership  thereof as of the Agreement Date are as set forth on Schedule  4.1(c)
attached   hereto,   and  to  the  extent  such  Restricted   Subsidiaries   are
corporations,  the  Borrower has the  unrestricted  right to vote the issued and
outstanding shares of the Restricted  Subsidiaries shown thereon and such shares
of such  Restricted  Subsidiaries  have been duly  authorized and issued and are
fully paid and 

                                       -36-
<PAGE>

nonassessable.  Each  Restricted  Subsidiary  of the Borrower has the  corporate
power and has taken all necessary  corporate  action to authorize it to execute,
deliver  and  perform  each of the  Loan  Documents  to  which  it is a party in
accordance  with  their  respective  terms and to  consummate  the  transactions
contemplated  by this  Agreement  and by such Loan  Documents.  Each of the Loan
Documents  to which any  Restricted  Subsidiary  of the  Borrower  is party is a
legal,  valid and binding obligation of such Restricted  Subsidiary  enforceable
against such Restricted  Subsidiary in accordance with its terms, subject, as to
enforcement  of  remedies,  to  applicable  bankruptcy,  insolvency,  fraudulent
conveyance,  reorganization,  moratorium and similar laws  affecting  creditors'
rights and remedies  generally,  and subject,  as to enforceability,  to general
principles  of  equity.  The  Borrower's  ownership  interest  in  each  of  its
Restricted  Subsidiaries represents a direct or indirect controlling interest of
such Restricted Subsidiary for purposes of directing or causing the direction of
the management and policies of each Restricted Subsidiary.

                  (d)  Compliance  with Other Loan  Documents  and  Contemplated
Transactions.  The execution, delivery and performance, in accordance with their
respective  terms,  by the Borrower of this Agreement and the Notes,  and by the
Borrower and its Restricted  Subsidiaries of each of the other Loan Documents to
which they are  respectively  party,  and the  consummation of the  transactions
contemplated  hereby and thereby, do not and will not (i) require any consent or
approval,  governmental  or otherwise,  not already  obtained,  (ii) violate any
Applicable  Law  respecting  the Borrower or any  Restricted  Subsidiary  of the
Borrower,  (iii) conflict  with,  result in a breach of, or constitute a default
under the  certificate  or articles of  incorporation  or by-laws or partnership
agreements, as the case may be, as amended, of the Borrower or of any Restricted
Subsidiary of the Borrower, or under any material indenture, agreement, or other
instrument,  including without limitation the Licenses, to which the Borrower or
any of its Restricted  Subsidiaries  is a party or by which any of them or their
respective properties may be bound, or (iv) result in or require the creation or
imposition  of any  Lien  upon or with  respect  to any  property  now  owned or
hereafter acquired by the Borrower or any of its Restricted Subsidiaries, except
for Permitted Liens.

                  (e) Business. The Borrower, together with its Subsidiaries, is
engaged  in the  business  of owning,  constructing,  managing,  operating,  and
investing in communications tower facilities.

                   (f) Licenses, etc. The Licenses have been duly issued and are
in full force and effect.  The Borrower and its Restricted  Subsidiaries  are in
compliance in all material  respects  with all of the  provisions  thereof.  The
Borrower  and  its   Restricted   Subsidiaries   have   secured  all   Necessary
Authorizations  and all such  Necessary  Authorizations  are in full  force  and
effect.  Neither any License nor any Necessary  Authorization  is the subject of
any pending or, to the best of the Borrower's knowledge, threatened revocation.

                                       -37-
<PAGE>


                   (g)  Compliance  with Law. The  Borrower  and its  Restricted
Subsidiaries are in compliance with all Applicable Law, except where the failure
to be in compliance  would not  individually or in the aggregate have a Material
Adverse Effect.                          

                  (h) Title to Assets.  As of the Agreement  Date,  the Borrower
and its Restricted  Subsidiaries  have good, legal and marketable title to, or a
valid leasehold interest in, all of its assets. None of the properties or assets
of the Borrower or any of its Restricted  Subsidiaries  is subject to any Liens,
except for Permitted Liens. Except for financing statements evidencing Permitted
Liens, no financing  statement under the Uniform Commercial Code as in effect in
any  jurisdiction  and no other  filing  which names the  Borrower or any of its
Restricted  Subsidiaries  as debtor or which  covers or purports to cover any of
the assets of the Borrower or any of its  Restricted  Subsidiaries  is currently
effective  and on file in any  state  or other  jurisdiction,  and  neither  the
Borrower nor any of its  Restricted  Subsidiaries  has signed any such financing
statement  or filing or any security  agreement  authorizing  any secured  party
thereunder to file any such financing statement or filing.

                  (i)  Litigation.  As of the date  hereof,  there is no action,
suit,  proceeding or investigation  pending against, or, to the knowledge of the
Borrower,  threatened  against or in any other manner relating adversely to, the
Borrower  or any of  its  Restricted  Subsidiaries  or any of  their  respective
properties,  including without  limitation the Licenses,  in any court or before
any  arbitrator  of any kind or before or by any  governmental  body  (including
without  limitation  the FCC)  except as set forth on Schedule  4.1(i)  attached
hereto (as such  schedule  may be updated  from time to time).  No such  action,
suit,  proceeding or investigation  (i) calls into question the validity of this
Agreement  or any other Loan  Document,  or (ii)  individually  or  collectively
involves  the  possibility  of any judgment or  liability  not fully  covered by
insurance  which,  if  determined  adversely  to  the  Borrower  or  any  of its
Restricted Subsidiaries, would have a Materially Adverse Effect.

                  (j) Taxes.  All  federal,  state and other tax  returns of the
Borrower  and each of its  Restricted  Subsidiaries  required by law to be filed
have been duly filed and all federal, state and other taxes, including,  without
limitation,  withholding taxes,  assessments and other  governmental  charges or
levies required to be paid by the Borrower or any of its Restricted Subsidiaries
or imposed upon the  Borrower or any of its  Restricted  Subsidiaries  or any of
their  respective  properties,  income,  profits  or  assets,  which are due and
payable,  have been paid, except any such taxes (i) (x) the payment of which the
Borrower or any of its Restricted  Subsidiaries is diligently contesting in good
faith by  appropriate  proceedings,  (y) for which  adequate  reserves have been
provided  on the  books of the  Borrower  or the  Restricted  Subsidiary  of the
Borrower  involved,  and (z) as to which no Lien other than a Permitted Lien has
attached and no foreclosure,  distraint,  sale or similar  proceedings have been
commenced, or (ii) which may result from audits not yet conducted.  The charges,
accruals and  reserves 

                                       -38-
<PAGE>


on the books of the Borrower and each of its Restricted  Subsidiaries in respect
of taxes are, in the judgment of the Borrower, adequate.

                  (k) Financial Statements. The Borrower has furnished or caused
to be furnished to the  Administrative  Agent and the Banks as of the  Agreement
Date,  the audited  financial  statements  for  American  Radio  Systems and its
Subsidiaries  on a  consolidated  basis for the fiscal year ended  December  31,
1996,  and unaudited  financial  statements  for the Borrower and its Restricted
Subsidiaries  for the fiscal quarter ended June 30, 1997, all of which have been
prepared in accordance with GAAP and present fairly in all material respects the
financial  position  of  the  Borrower  and  its  Restricted  Subsidiaries  on a
consolidated  basis,  on and as at such dates and the results of operations  for
the periods then ended (subject,  in the case of unaudited financial statements,
to normal year-end and audit  adjustments).  Neither the Borrower nor any of its
Restricted  Subsidiaries has any material liabilities,  contingent or otherwise,
other than as disclosed in the financial statements referred to in the preceding
sentence or as set forth or referred to in this Agreement.

                   (l) No Material  Adverse Change.  There has occurred no event
since December 31, 1996 which has or which could  reasonably be expected to have
a Materially Adverse Effect.                          

                  (m) ERISA.  The Borrower and each  Subsidiary  of the Borrower
and each of their respective Plans are in compliance with ERISA and the Code and
neither  the  Borrower  nor  any  of  its  ERISA   Affiliates,   including   its
Subsidiaries,  has incurred any accumulated  funding  deficiency with respect to
any such Plan within the meaning of ERISA or the Code. The Borrower, each of its
Subsidiaries,  and each other ERISA  Affiliate  have  complied  in all  material
respects  with all  requirements  of ERISA.  Neither the Borrower nor any of its
Subsidiaries has made any promises of retirement or other benefits to employees,
except as set forth in the Plans, in written agreements with such employees,  or
in the  Borrower's  employee  handbook and memoranda to  employees.  Neither the
Borrower  nor any of its  ERISA  Affiliates,  including  its  Subsidiaries,  has
incurred any material  liability to PBGC in connection  with any such Plan.  The
assets of each such Plan which is subject to Title IV of ERISA are sufficient to
provide the benefits under such Plan, the payment of which PBGC would  guarantee
if such Plan were terminated, and such assets are also sufficient to provide all
other  "benefit  liabilities"  (within the meaning of Section 4041 of ERISA) due
under  the Plan upon  termination.  No  Reportable  Event  has  occurred  and is
continuing  with  respect  to any  such  Plan.  No such  Plan or  trust  created
thereunder,  or party in interest (as defined in Section 3(14) of ERISA), or any
fiduciary (as defined in Section  3(21) of ERISA),  has engaged in a "prohibited
transaction" (as such term is defined in Section 406 of ERISA or Section 4975 of
the Code) which would subject such Plan or any other Plan of the Borrower or any
of its Subsidiaries, any trust created thereunder, or any such party in interest
or fiduciary,  or any party dealing with any such Plan or any such trust, to the
tax or penalty on "prohibited  transactions"  imposed by Section 502 of ERISA or

                                       -39-
<PAGE>


Section 4975 of the Code.  Neither the Borrower nor any of its ERISA Affiliates,
including its  Subsidiaries,  is or has been  obligated to make any payment to a
Multiemployer Plan.

                  (n)  Compliance  with  Regulations  G, T, U and X. Neither the
Borrower  nor  any  of  the  Borrower's   Restricted   Subsidiaries  is  engaged
principally  or as one of its important  activities in the business of extending
credit for the purpose of purchasing  or carrying,  and neither the Borrower nor
any of the  Borrower's  Restricted  Subsidiaries  owns or  presently  intends to
acquire, any "margin security" or "margin stock" as defined in Regulations G, T,
U, and X (12 C.F.R.  Parts 207,  220,  221 and 224) of the Board of Governors of
the Federal Reserve System (herein called "margin stock").  None of the proceeds
of the Loans will be used, directly or indirectly, for the purpose of purchasing
or carrying  any margin  stock or for the  purpose of  reducing or retiring  any
Indebtedness which was originally  incurred to purchase or carry margin stock or
for any other purpose which might constitute this transaction a "purpose credit"
within the  meaning of said  Regulations  G, T, U, and X. The  Borrower  has not
taken,  caused or  authorized  to be taken,  and will not take any action  which
might cause this  Agreement or the Notes to violate  Regulation G, T, U, or X or
any other  regulation of the Board of Governors of the Federal Reserve System or
to violate the Securities Exchange Act of 1934, in each case as now in effect or
as the same may  hereafter be in effect.  If so requested by the  Administrative
Agent, the Borrower will furnish the  Administrative  Agent with (i) a statement
or statements in conformity  with the  requirements of Federal Reserve Forms G-3
and/or U-I referred to in  Regulations  G and U of said Board of  Governors  and
(ii) other  documents  evidencing  its compliance  with the margin  regulations,
reasonably  requested  by the  Administrative  Agent.  Neither the making of the
Loans nor the use of proceeds thereof will violate, or be inconsistent with, the
provisions of Regulation G, T, U, or X of said Board of Governors.

                  (o)  Investment  Company Act.  Neither the Borrower nor any of
its Restricted  Subsidiaries is required to register under the provisions of the
Investment  Company Act of 1940,  as amended,  and neither the entering  into or
performance  by the Borrower and its Restricted  Subsidiaries  of this Agreement
and the Loan  Documents nor the issuance of the Notes  violates any provision of
such Act or requires any consent,  approval or authorization of, or registration
with, the Securities and Exchange Commission or any other governmental or public
body or authority pursuant to any provisions of such Act.

                  (p) Governmental  Regulation.  Neither the Borrower nor any of
its  Restricted  Subsidiaries  is  required  to obtain  any  consent,  approval,
authorization,  permit or license which has not already been  obtained  from, or
effect any filing or registration  which has not already been effected with, any
federal,  state or local  regulatory  authority in connection with the execution
and delivery of this Agreement or any other Loan Document.  Neither the Borrower
nor any of its  Restricted  Subsidiaries  is  required  to obtain  any  consent,
approval,  authorization,  permit or license which has not already been obtained
from, or effect any filing or  registration  which has not already been effected
with, any federal,  state or local  

                                       -40-
<PAGE>


regulatory  authority in connection  with the  performance,  in accordance  with
their respective terms, of this Agreement or any other Loan Document, other than
filing of appropriate UCC financing statements and mortgages.

                  (q) Absence of Default,  Etc. The Borrower and its  Restricted
Subsidiaries  are in compliance  in all respects  with all of the  provisions of
their   respective   partnership   agreements,   Certificates   or  Articles  of
Incorporation  and  By-Laws,  as the case may be, and no event has  occurred  or
failed to occur (including,  without limitation, any matter which could create a
Default hereunder by cross-default)  which has not been remedied or waived,  the
occurrence  or  non-occurrence  of which  constitutes,  (i) a Default  or (ii) a
material default by the Borrower or any of its Restricted Subsidiaries under any
indenture,  agreement  or  other  instrument  relating  to  Indebtedness  of the
Borrower or any of its  Restricted  Subsidiaries  in the amount of $1,000,000 or
more in the aggregate, any material License, or any judgment, decree or order to
which the Borrower or any of its Restricted  Subsidiaries is a party or by which
the Borrower or any of its Restricted  Subsidiaries  or any of their  respective
properties may be bound or affected.

                  (r) Accuracy and Completeness of Information. All information,
reports,  prospectuses and other papers and data relating to the Borrower or any
of its Restricted  Subsidiaries and furnished by or on behalf of the Borrower or
any of its Restricted  Subsidiaries  to the  Administrative  Agent or the Banks,
taken as a whole, were, at the time furnished, true, complete and correct in all
material respects to the extent necessary to give the  Administrative  Agent and
the  Banks  true  and  accurate   knowledge  of  the  subject  matter,  and  all
projections,  consisting of a  consolidated  projected cash flow  statement,  an
income  statement,   and  a  balance  sheet  for  Borrower  and  its  Restricted
Subsidiaries (the  "Projections") (i) disclose all assumptions made with respect
to costs,  general  economic  conditions,  and financial  and market  conditions
formulating  the  Projections;  (ii)  are  based  on  reasonable  estimates  and
assumptions;  and  (iii)  reflect,  as of the date  prepared,  and  continue  to
reflect,  as of the date  hereof,  the  reasonable  estimate  of Borrower of the
results of operations and other  information  projected  therein for the periods
covered thereby.

                  (s)  Agreements  with  Affiliates.  Except for  agreements  or
arrangements  with  Affiliates  wherein  the  Borrower  or  one or  more  of its
Restricted   Subsidiaries   provides   services  to  such  Affiliates  for  fair
consideration or which are set forth on Schedule 4.l(s) attached hereto, neither
the  Borrower  nor  any of its  Restricted  Subsidiaries  has  (i)  any  written
agreements  or binding  arrangements  of any kind with any Affiliate or (ii) any
management or consulting  agreements of any kind with any Affiliate,  other than
those between the Borrower and its Restricted Subsidiaries.

                   (t) Payment of Wages. The Borrower and each of its Restricted
Subsidiaries are in compliance with the Fair Labor Standards Act, as amended, in
all  material  respects,  and to the  knowledge  of the Borrower and each of its
Subsidiaries,  such Persons 

                                       -41-
<PAGE>


have paid all minimum  and  overtime  wages  required by law to be paid to their
respective employees.

                  (u)  Priority.  The  Security  Interest  is a valid and,  upon
filing of  appropriate  UCC financing  statements  and/or  mortgages,  will be a
perfected  first  priority  security  interest in the Collateral in favor of the
Administrative  Agent,  for the  benefit of itself and the Banks,  securing,  in
accordance with the terms of the Security  Documents,  the Obligations,  and the
Collateral is subject to no Liens other than Permitted  Liens. The Liens created
by the Security  Documents are  enforceable  as security for the  Obligations in
accordance  with their  terms  with  respect to the  Collateral  subject,  as to
enforcement  of  remedies,  to the  following  qualifications:  (i) an  order of
specific  performance  and an  injunction  are  discretionary  remedies  and, in
particular, may not be available where damages are considered an adequate remedy
at  law,  and  (ii)  enforcement  may  be  limited  by  bankruptcy,  insolvency,
liquidation,  reorganization,  reconstruction  and other similar laws  affecting
enforcement of creditors'  rights generally  (insofar as any such law relates to
the  bankruptcy,  insolvency  or  similar  event of the  Borrower  or any of its
Subsidiaries, as the case may be).

                   (v) Indebtedness. Except as shown on the financial statements
of Borrower  for the fiscal  quarter  ended June 30,  1997,  or as  described on
Schedule  4.l(v)  attached hereto neither the Borrower nor any of its Restricted
Subsidiaries has outstanding,  as of the Agreement Date, and after giving effect
to the initial  Advances  hereunder on the Agreement Date, any  Indebtedness for
Money Borrowed.
                          

                  (w) Solvency. As of the Agreement Date and after giving effect
to the  transactions  contemplated by the Loan Documents (i) the property of the
Borrower,  at a fair  valuation,  will exceed its debt;  (ii) the capital of the
Borrower  will not be  unreasonably  small to conduct  its  business;  (iii) the
Borrower will not have incurred debts,  or have intended to incur debts,  beyond
its ability to pay such debts as they mature;  and (iv) the present fair salable
value of the assets of the Borrower will be greater than the amount that will be
required  to pay its  probable  liabilities  (including  debts)  as they  become
absolute and matured.  For purposes of this Section,  "debt" means any liability
on a claim,  and  "claim"  means (i) the right to  payment,  whether or not such
right is reduced  to  judgment,  liquidated,  unliquidated,  fixed,  contingent,
matured, unmatured,  undisputed, legal, equitable, secured or unsecured, or (ii)
the right to an equitable  remedy for breach of performance if such breach gives
rise to a right to payment,  whether or not such right to an equitable remedy is
reduced to judgment, fixed, contingent, matured, unmatured,  undisputed, secured
or unsecured.

         Section 4.2  Survival  of  Representations  and  Warranties,  Etc.  All
representations  and  warranties  made under this  Agreement  and any other Loan
Document  shall be  deemed  to be made,  and  shall be true and  correct  in all
material  respects,  at and as of the  Agreement  Date  and on the  date of each
Advance except to the extent  relating  specifically  to the Agreement Date. All
representations  and  warranties  made under this  Agreement  and the 

                                       -42-
<PAGE>

other Loan Documents shall survive,  and not be waived by, the execution  hereof
by the Banks and the  Administrative  Agent, any investigation or inquiry by any
Bank or the  Administrative  Agent,  or the  making of any  Advance  under  this
Agreement.

                          ARTICLE 5 General Covenants

         So long as any of the  Obligations  is  outstanding  and  unpaid or the
Banks  have  an  obligation  to  fund  Advances  hereunder  (whether  or not the
conditions to borrowing have been or can be fulfilled),  and unless the Majority
Banks,  or such  greater  number of Banks as may be expressly  provided  herein,
shall otherwise consent in writing:

         Section 5.1  Preservation of Existence and Similar  Matters.  Except as
permitted  under Section 7.4 hereof,  the Borrower  will, and will cause each of
its Restricted Subsidiaries to:                                    

                   (a) preserve and  maintain  its  existence,  and its material
rights,  franchises,  licenses and privileges in the state of its incorporation,
including,  without limiting the foregoing, the Licenses and all other Necessary
Authorizations; and

                   (b)  qualify  and  remain  qualified  and  authorized  to  do
business in each  jurisdiction  in which the character of its  properties or the
nature of its business requires such qualification or authorization,  except for
such  failure to so qualify  and be so  authorized  as could not  reasonably  be
expected to have a Material Adverse Effect.

         Section 5.2  Business;  Compliance  with  Applicable  Law. The Borrower
will, and will cause each of its Restricted  Subsidiaries  to, (a) engage in the
business  of  owning,   constructing,   managing,  operating  and  investing  in
communications   tower  facilities  and  related  businesses  and  no  unrelated
activities, and (b) comply in all material respects with the requirements of all
Applicable Law.
                                    
         Section 5.3  Maintenance  of  Properties.  The Borrower  will, and will
cause each of its Restricted Subsidiaries to, maintain or cause to be maintained
in the ordinary  course of business in good repair,  working order and condition
(reasonable  wear and tear  excepted) all  properties  used in their  respective
businesses (whether owned or held under lease), other than obsolete equipment or
unused  assets  and from  time to time make or cause to be made all  needed  and
appropriate  repairs,  renewals,   replacements,   additions,   betterments  and
improvements thereto.

         Section 5.4  Accounting  Methods and  Financial  Records.  The Borrower
will, and will cause each of its Restricted  Subsidiaries on a consolidated  and
consolidating  basis  to,  maintain  a  system  of  accounting  established  and
administered in accordance with GAAP,

                                       -43-
<PAGE>

keep  adequate  records and books of account in which  complete  entries will be
made in accordance  with GAAP and  reflecting  all  transactions  required to be
reflected by GAAP and keep  accurate and  complete  records of their  respective
properties  and  assets.  The  Borrower  and its  Restricted  Subsidiaries  will
maintain a fiscal year ending on December 31.

         Section 5.5  Insurance.  The Borrower  will, and will cause each of its
Restricted Subsidiaries to:        

                   (a)  Maintain  insurance  including,   but  not  limited  to,
business  interruption  coverage and public  liability  coverage  insurance from
responsible companies in such amounts and against such risks to the Borrower and
each  of its  Restricted  Subsidiaries  as is  prudent  for  similarly  situated
companies engaged in the communications tower industry.

                   (b) Keep their respective assets insured by insurers on terms
and in a manner reasonably  acceptable to the Administrative  Agent against loss
or damage by fire,  theft,  burglary,  loss in transit,  explosions  and hazards
insured  against by  extended  coverage,  in amounts  which are  prudent for the
communications   tower   management   and  operation   industry  and  reasonably
satisfactory to the Administrative Agent, all premiums thereon to be paid by the
Borrower and its Restricted Subsidiaries.

                   (c) Require that each  insurance  policy provide for at least
thirty  (30)  days'  prior  written  notice to the  Administrative  Agent of any
termination of or proposed  cancellation or nonrenewal of such policy,  and name
the  Administrative  Agent  as  additional  named  lender  loss  payee  and,  as
appropriate, additional insured, to the extent of the Obligations.

         Section 5.6 Payment of Taxes and Claims.  The Borrower  will,  and will
cause  each of its  Restricted  Subsidiaries  to, pay and  discharge  all taxes,
including,  without limitation,  withholding taxes, assessments and governmental
charges  or levies  required  to be paid by them or  imposed  upon them or their
income or profits or upon any properties belonging to them, prior to the date on
which penalties attach thereto,  and all lawful claims for labor,  materials and
supplies  which,  if  unpaid,  might  become a Lien or charge  upon any of their
properties;  except that no such tax, assessment,  charge, levy or claim need be
paid  which  is  being  diligently   contested  in  good  faith  by  appropriate
proceedings  and for which  adequate  reserves  shall have been set aside on the
appropriate  books, but only so long as such tax,  assessment,  charge,  levy or
claim  does not  become a Lien or  charge  other  than a  Permitted  Lien and no
foreclosure,  distraint,  sale or similar proceedings shall have been commenced.
The Borrower will, and will cause each of its Restricted Subsidiaries to, timely
file  all  information   returns  required  by  federal,   state  or  local  tax
authorities.

                                       -44-
<PAGE>


         Section 5.7 Compliance with ERISA.

                   (a) The Borrower shall,  and shall cause its Subsidiaries to,
make all contributions to any Employee Pension Plan when such  contributions are
due and not incur any  "accumulated  funding  deficiency"  within the meaning of
Section 412(a) of the Code,  whether or not waived,  and will  otherwise  comply
with the requirements of the Code and ERISA with respect to the operation of all
Plans,  except to the  extent  that the  failure  to so comply  could not have a
Materially Adverse Effect.

                   (b) The Borrower shall,  and shall cause its Subsidiaries to,
comply in all respects with the  requirements of ERISA with respect to any Plans
subject to the requirements thereof, except to the extent that the failure to so
comply could not have a Materially Adverse Effect.

                  (c) The Borrower  shall  furnish to  Administrative  Agent (i)
within 30 days  after any  officer  of the  Borrower  obtains  knowledge  that a
"prohibited  transaction" (within the meaning of Section 406 of ERISA or Section
4975 of the Code) has  occurred  with respect to any Plan of the Borrower or its
ERISA  Affiliates,  including its  Subsidiaries,  that any Reportable  Event has
occurred with respect to any Employee  Pension Plan or that PBGC has  instituted
or will institute  proceedings under Title IV of ERISA to terminate any Employee
Pension Plan or to appoint a trustee to administer any Employee  Pension Plan, a
statement  setting  forth  the  details  as  to  such  prohibited   transaction,
Reportable Event or termination or appointment  proceedings and the action which
it (or any other  Employee  Pension  Plan  sponsor if other  than the  Borrower)
proposes to take with  respect  thereto,  together  with a copy of the notice of
such Reportable Event given to PBGC if a copy of such notice is available to the
Borrower, any of its Subsidiaries or any of its ERISA Affiliates,  (ii) promptly
after  receipt  thereof,  a  copy  of  any  notice  the  Borrower,  any  of  its
Subsidiaries or any of its ERISA  Affiliates or the sponsor of any Plan receives
from PBGC, or the Internal Revenue Service or the Department of Labor which sets
forth or proposes any action or  determination  with respect to such Plan, (iii)
promptly  after the filing  thereof,  any  annual  report  required  to be filed
pursuant to ERISA in connection with each Plan maintained by the Borrower or any
of its ERISA Affiliates,  including the Subsidiaries, and (iv) promptly upon the
Administrative Agent's request therefor,  such additional information concerning
any such Plan as may be reasonably requested by the Administrative Agent.

                   (d) The  Borrower  will  promptly  notify the  Administrative
Agent of any excise taxes which have been assessed or which the Borrower, any of
its  Subsidiaries  or any of its ERISA  Affiliates  has reason to believe may be
assessed  against  the  Borrower,  any of its  Subsidiaries  or any of its ERISA
Affiliates  by the  Internal  Revenue  Service or the  Department  of Labor with
respect  to any Plan of the  Borrower  or its ERISA  Affiliates,  including  its
Subsidiaries.

                                       -45-
<PAGE>


                   (e)  Within  the time  required  for notice to the PBGC under
Section 302(f)(4)(A) of ERISA, the Borrower will notify the Administrative Agent
of any lien arising  under  Section  302(f) of ERISA in favor of any Plan of the
Borrower or its ERISA Affiliates, including its Subsidiaries.

                   (f) The  Borrower  will not,  and will not  permit any of its
Subsidiaries  or any of its  ERISA  Affiliates,  to  take  any of the  following
actions or permit any of the  following  events to occur if such action or event
together with all other such actions or events would  subject the Borrower,  any
of its  Subsidiaries,  or any of its ERISA  Affiliates to any tax,  penalty,  or
other liabilities which could have a Materially Adverse Effect:

                           (i)  engage in any  transaction  in  connection  with
                  which  the  Borrower,  any of its  Subsidiaries  or any  ERISA
                  Affiliate could be subject to either a civil penalty  assessed
                  pursuant  to  Section  502(i)  of  ERISA or a tax  imposed  by
                  Section 4975 of the Code;

                           (ii) terminate any Employee Pension Plan in a manner,
                  or take any other action,  which could result in any liability
                  of  the  Borrower,  any  of  its  Subsidiaries  or  any  ERISA
                  Affiliate to the PBGC;

                           (iii)  fail  to make  full  payment  when  due of all
                  amounts which, under the provisions of any Plan, the Borrower,
                  any of its  Subsidiaries or any ERISA Affiliate is required to
                  pay  as  contributions   thereto,   or  permit  to  exist  any
                  accumulated  funding  deficiency within the meaning of Section
                  412(a) of the Code, whether or not waived, with respect to any
                  Employee Pension Plan; or

                           (iv)  permit  the   present   value  of  all  benefit
                  liabilities under all Employee Pension Plans which are subject
                  to Title IV of ERISA to exceed the present value of the assets
                  of such Plans  allocable to such benefit  liabilities  (within
                  the  meaning  of  Section  4041 of  ERISA),  except  as may be
                  permitted  under  actuarial   funding   standards  adopted  in
                  accordance with Section 412 of the Code.

         Section 5.8 Visits and  Inspections.  The Borrower will, and will cause
each  of  its  Restricted   Subsidiaries  to,  permit   representatives  of  the
Administrative  Agent and any of the Banks, upon reasonable notice, to (a) visit
and inspect the properties of the Borrower or any of its Restricted Subsidiaries
during  business  hours,  (b) inspect and make extracts from and copies of their
respective books and records,  and (c) discuss with their  respective  principal
officers their respective businesses, assets, liabilities,  financial positions,
results of  operations  and  business  prospects.  The  Borrower and each of its
Restricted  Subsidiaries will also permit  representatives of the Administrative
Agent and any of the Banks to discuss  with  their  respective  accountants  the
Borrower's  and the  Borrower's  Restricted  Subsidiaries'  businesses,  assets,
liabilities, financial positions, results of operations and business prospects.

                                       -46-
<PAGE>


         Section 5.9 Payment of Indebtedness;  Loans.  Subject to any provisions
herein or in any other Loan Document,  the Borrower will, and will cause each of
its Restricted Subsidiaries to, pay any and all of their respective Indebtedness
when and as it becomes due, other than amounts diligently disputed in good faith
and for which adequate reserves have been set aside in accordance with GAAP.  

         Section  5.10 Use of  Proceeds.  The  Borrower  will use the  aggregate
proceeds of all Advances under the Loans directly or indirectly:          

                   (a) to fund Acquisitions permitted by Section 7.6 hereof;

                  (b) to fund Capital Expenditures to the extent permitted under
Section 7.11 hereof; and

                   (c) for working capital needs and other corporate purposes of
the Borrower and its Restricted Subsidiaries (including, without limitation, the
fees and expenses incurred in connection with the execution and delivery of this
Agreement) which do not otherwise conflict with this Section 5.10.

No proceeds of Advances  hereunder shall be used for the purchase or carrying or
the extension of credit for the purpose of  purchasing  or carrying,  any margin
stock within the meaning of Regulations G, T, U, and X of the Board of Governors
of the Federal Reserve System.

         Section  5.11 Real  Estate.  The  Borrower  shall,  and shall cause its
Restricted  Subsidiaries  to, within  ninety (90) days from the Agreement  Date,
and,  thereafter,  within thirty (30) days of the acquisition of any real estate
permitted  under  Section  7.13  hereof  and within  thirty  (30) days after the
reports  produced  pursuant  to Section  6.6  hereof,  grant a  mortgage  to the
Administrative  Agent  securing the  Obligations  (or such amount  thereof as is
equal to the fair  market  value of such real  estate if the  Majority  Banks so
permit),  in form and substance  reasonably  satisfactory to the  Administrative
Agent,  covering  the parcels of real estate owned by the Borrower or any of its
Restricted  Subsidiaries  which  in the  aggregate  account  for not  less  than
seventy-five percent (75%) of the revenues generated by all such parcels of real
estate  based upon the reports  required  pursuant  to Section  6.6 hereof.  The
Borrower shall,  and shall cause its Restricted  Subsidiaries to, deliver to the
Administrative  Agent all  documentation,  including  opinions  of  counsel  and
policies  of  title   insurance,   which  in  the  reasonable   opinion  of  the
Administrative Agent are appropriate with each such grant, including any phase I
environmental audit requested by the Majority Banks.

         Section  5.12  Indemnity.  The Borrower  agrees to  indemnify  and hold
harmless  each Bank,  the  Administrative  Agent,  and each of their  respective
affiliates,  employees,

                                       -47-
<PAGE>

representatives,  shareholders,  officers and  directors  (any of the  foregoing
shall be an  "Indemnitee")  from and against  any and all  claims,  liabilities,
losses, damages, actions,  reasonable attorneys' fees and expenses (as such fees
and  expenses are  incurred)  and demands by any party,  including  the costs of
investigating  and  defending  such  claims,  whether or not the  Borrower,  any
Restricted  Subsidiary or the Person seeking  indemnification  is the prevailing
party (a)  resulting  from any breach or alleged  breach by the  Borrower or any
Restricted  Subsidiary  of the Borrower of any  representation  or warranty made
hereunder or under any Loan  Document;  or (b) otherwise  arising out of (i) the
Commitment  or  otherwise  under  this  Agreement,  any  Loan  Document  or  any
transaction contemplated hereby or thereby,  including,  without limitation, the
use of the  proceeds of Loans  hereunder  in any fashion by the  Borrower or the
performance  of their  respective  obligations  under the Loan  Documents by the
Borrower  or  any  of  its  Restricted  Subsidiaries,  (ii)  allegations  of any
participation  by the Banks,  the  Administrative  Agent, or any of them, in the
affairs of the Borrower or any of its  Subsidiaries,  or allegations that any of
them  has  any  joint  liability  with  the  Borrower  or any of its  Restricted
Subsidiaries   for  any  reason,   (iii)  any  claims  against  the  Banks,  the
Administrative Agent, or any of them, by any shareholder or other investor in or
lender to the Borrower or any Restricted  Subsidiary,  by any brokers or finders
or investment  advisers or investment bankers retained by the Borrower or by any
other  third  party,  arising  out of the  Commitment  or  otherwise  under this
Agreement;  or (c) in  connection  with  taxes (not  including  federal or state
income or  franchise  taxes or other  taxes based  solely  upon the  revenues or
income of such Persons),  fees, and other charges payable in connection with the
Loans,  or the  execution,  delivery,  and  enforcement of this  Agreement,  the
Security  Documents,  the other Loan  Documents,  and any amendments  thereto or
waivers  of  any  of  the   provisions   thereof,   unless  the  Person  seeking
indemnification  hereunder is  determined  in such case to have acted with gross
negligence  or  willful  misconduct,  in any  case,  by a final,  non-appealable
judicial  order.  The obligations of the Borrower under this Section 5.12 are in
addition to, and shall not otherwise limit,  any liabilities  which the Borrower
might otherwise have in connection with any warranties or similar obligations of
the Borrower in any other Loan Document.

         Section  5.13  Interest  Rate  Hedging.  Within  sixty (60) days of the
Agreement Date and forty-five  (45) days after each Advance,  the Borrower shall
enter into (and shall at all times thereafter  maintain for a period of not less
than two (2) years) one or more Interest  Hedge  Agreements  with respect to the
Borrower's  interest  obligations  on not less than fifty  percent  (50%) of the
principal amount of the Loans outstanding from time to time. Such Interest Hedge
Agreements   shall  provide   interest  rate   protection  in  conformity   with
International Swap Dealers Association standards and for an average period of at
least two (2)  years  from the date of such  Interest  Hedge  Agreements  or, if
earlier,  until  the  Maturity  Date  on  terms  reasonably  acceptable  to  the
Administrative   Agent,   such   terms   to   include   consideration   of   the
creditworthiness  of the other party to the proposed  Interest Hedge  Agreement.
All  Obligations  of the Borrower to either  Administrative  Agent or any of the
Banks pursuant to any Interest  Hedge  Agreement and all Liens granted to secure
such  

                                       -48-
<PAGE>


Obligations  shall rank pari passu with all other Obligations and Liens securing
such other  Obligations;  and any Interest Hedge Agreement  between the Borrower
and any other Person shall be unsecured.

         Section 5.14 Covenants Regarding  Formation of Restricted  Subsidiaries
and Acquisitions;  Partnership, Subsidiaries. At the time of (i) any Acquisition
permitted hereunder,  (ii) the purchase by the Borrower or any of its Restricted
Subsidiaries  of any interests in any Restricted or  Unrestricted  Subsidiary of
the  Borrower,  or (iii) the  formation of any new  Restricted  or  Unrestricted
Subsidiary  of the  Borrower  or any of its  Restricted  Subsidiaries  which  is
permitted under this Agreement, the Borrower will, and will cause its Restricted
Subsidiaries,  as  appropriate,  to (a) provide to the  Administrative  Agent an
executed  Subsidiary  Security Agreement for any new Restricted  Subsidiary,  in
substantially  the form of Exhibit J attached hereto,  together with appropriate
UCC-1 financing statements,  as well as an executed Subsidiary Guaranty for such
new  Restricted  Subsidiary,  in  substantially  the form of  Exhibit H attached
hereto,  which shall  constitute both Security  Documents and Loan Documents for
purposes  of  this  Agreement,  as  well  as a loan  certificate  for  such  new
Restricted  Subsidiary,  substantially in the form of Exhibit M attached hereto,
together with appropriate  attachments;  (b) pledge to the Administrative  Agent
all of the stock or  partnership  interests (or other  instruments or securities
evidencing  ownership) of such Subsidiary or Person which is acquired or formed,
beneficially  owned  by  the  Borrower  or  any  of  the  Borrower's  Restricted
Subsidiaries,  as the case may be, as additional  Collateral for the Obligations
to be held by the  Administrative  Agent in  accordance  with  the  terms of the
Borrower's   Pledge   Agreement,   or  a  new  Subsidiary  Pledge  Agreement  in
substantially the form of Exhibit I attached hereto,  and execute and deliver to
the  Administrative  Agent all such  documentation  for such  pledge  as, in the
reasonable  opinion of the  Administrative  Agent, is appropriate;  and (c) with
respect to any Acquisition or Restricted  Subsidiary,  provide revised financial
projections  for the remainder of the fiscal year and for each  subsequent  year
until the Maturity Date which reflect such  Acquisition or formation,  certified
by the Chief  Financial  Officer of the  Borrower,  together with a statement by
such Person  that no Default  exists or would be caused by such  Acquisition  or
formation,  and all  other  documentation,  including  one or more  opinions  of
counsel,  reasonably  satisfactory  to the  Administrative  Agent which in their
reasonable  opinion  is  appropriate  with  respect to such  Acquisition  or the
formation of such Subsidiary.  Notwithstanding the foregoing, the Borrower shall
not be required to pledge any of the stock or other ownership  interests for any
Unrestricted  Subsidiary  which (x) was not formed or created in anticipation of
the Borrower's  direct or indirect  investment  therein and (y) at the time such
stock or  ownership  interest  was  acquired by the  Borrower or its  Restricted
Subsidiaries  is  subject  to a  restriction  on any  such  Lien  (whether  such
restriction is in such Person's formation documents or otherwise),  but shall be
required to grant the Administrative Agent (for the benefit of the Banks) a Lien
upon any right to receive distributions from such Unrestricted  Subsidiary.  Any
document,  agreement  or  instrument  (other than the  Projections)  executed or
issued  pursuant to this Section 5.14 shall be a "Loan Document" for purposes of
this Agreement.

                                       -49-
<PAGE>

         Section 5.15 Payment of Wages. The Borrower shall, and shall cause each
of  its  Restricted  Subsidiaries  to,  at all  times  comply,  in all  material
respects,  with the material  requirements  of the Fair Labor  Standards Act, as
amended,  including,  without limitation, the provisions of such Act relating to
the payment of minimum and  overtime  wages as the same may become due from time
to time.                                    

         Section 5.16 Further  Assurances.  The Borrower will promptly  cure, or
cause to be cured,  defects in the creation and issuance of any of the Notes and
the execution and delivery of the Loan  Documents  (including  this  Agreement),
resulting  from  any  acts  or  failure  to act by  the  Borrower  or any of the
Borrower's  Restricted  Subsidiaries  or any  employee or officer  thereof.  The
Borrower at its expense will promptly execute and deliver to the  Administrative
Agent and the Banks, or cause to be executed and delivered to the Administrative
Agent and the  Banks,  all such other and  further  documents,  agreements,  and
instruments in compliance with or accomplishment of the covenants and agreements
of the Borrower in the Loan Documents,  including this Agreement,  or to correct
any omissions in the Loan Documents,  or more fully to state the obligations set
out herein or in any of the Loan  Documents,  or to obtain any consents,  all as
may be necessary or appropriate in connection therewith and as may be reasonably
requested.

                        ARTICLE 6 Information Covenants

         So long as any of the  Obligations  is  outstanding  and  unpaid or the
Banks  have  an  obligation  to  fund  Advances  hereunder  (whether  or not the
conditions to borrowing  have been or can be fulfilled)  and unless the Majority
Banks shall otherwise consent in writing,  the Borrower will furnish or cause to
be  furnished to each Bank and the  Administrative  Agent,  at their  respective
offices:

         Section 6.1  Quarterly  Financial  Statements  and  Information  Within
forty-five  (45) days after the last day of each of the first three (3) quarters
of each fiscal year of the  Borrower,  the balance  sheets of the  Borrower on a
consolidated  basis with its Restricted  Subsidiaries and a consolidating  basis
with its  Unrestricted  Subsidiaries as at the end of such quarter and as of the
end of the preceding  fiscal year, and the related  statements of operations and
the related  statements  of cash flows of the Borrower on a  consolidated  basis
with its Restricted Subsidiaries and a consolidating basis with its Unrestricted
Subsidiaries for such quarter and for the elapsed portion of the year ended with
the last day of such  quarter,  which shall set forth in  comparative  form such
figures as at the end of and for such quarter and  appropriate  prior period and
shall be certified by the chief  financial  officer of the Borrower to have been
prepared in accordance with GAAP and to present fairly in all material  respects
the  financial  position  of the  Borrower  on a  consolidated  basis  with  its
Restricted   Subsidiaries  and  a  consolidating  basis  with  its  Unrestricted
Subsidiaries as at the end of such period and

                                       -50-
<PAGE>

the results of operations  for such period,  and for the elapsed  portion of the
year ended with the last day of such period, subject only to normal year-end and
audit adjustments.

         Section 6.2 Annual Financial Statements and Information.  Within ninety
(90)  days  after  the end of each  fiscal  year of the  Borrower,  the  audited
consolidated balance sheet of the Borrower and its Restricted  Subsidiaries (and
unaudited  consolidating  balance  sheet of the  Borrower  and its  Unrestricted
Subsidiaries)  as of the  end of  such  fiscal  year  and  the  related  audited
consolidated  and unaudited  consolidating  statements  of  operations  for such
fiscal year and for the previous fiscal year, the related  audited  consolidated
statements  of cash flow and  stockholders'  equity for such fiscal year and for
the previous  fiscal year,  which shall be accompanied by an opinion which shall
be in scope and substance reasonably satisfactory to the Administrative Agent of
Deloitte & Touche,  LLP, or other  independent  certified public  accountants of
recognized national standing reasonably  acceptable to the Administrative Agent,
together  with a statement of such  accountants  that in  connection  with their
audit,  nothing  came to their  attention  that caused them to believe  that the
Borrower  was  not in  compliance  with  the  terms,  covenants,  provisions  or
conditions of Sections 7.8, 7.9, 7.10 and 7.11 hereof  insofar as they relate to
accounting matters.

         Section  6.3  Performance  Certificates.  At  the  time  the  financial
statements are furnished  pursuant to Sections 6.1 and 6.2 hereof, a certificate
of the president or chief financial  officer of the Borrower as to its financial
performance, in substantially the form attached hereto as Exhibit N: 

                   (a) setting forth as and at the end of such quarterly  period
or fiscal year, as the case may be, the  arithmetical  calculations  required to
establish  (i) any  adjustment  to the  Applicable  Margins,  as provided for in
Section  2.3(f)  hereof,  and (ii) whether or not the Borrower was in compliance
with the requirements of Sections 7.7, 7.8, 7.9, 7.10 and 7.11 hereof;

                   (b) stating  that,  to the best of his or her  knowledge,  no
Default has occurred as at the end of such quarterly period or year, as the case
may be, or, if a Default  has  occurred,  disclosing  each such  Default and its
nature, when it occurred,  whether it is continuing and the steps being taken by
the Borrower with respect to such Default;

                   (c)  containing  a  list  of all  Acquisitions,  Investments,
Restricted  Payments and  dispositions of assets from the Agreement Date through
the date of such  certificate,  together  with the total  amount for each of the
foregoing categories; and

                  (d) setting  forth the amount of  distributions  received from
Unrestricted Subsidiaries for such period.

                                       -51-
<PAGE>


         Section 6.4 Copies of Other Reports.

                   (a) Promptly upon receipt thereof,  copies of all reports, if
any, submitted to the Borrower by the Borrower's  independent public accountants
regarding the Borrower,  including,  without  limitation,  any management report
prepared in connection with the annual audit referred to in Section 6.2 hereof.

                  (b)  Promptly  upon  receipt  thereof,  copies of any material
adverse notice or report regarding any License from the FCC.

                   (c) From time to time and promptly  upon each  request,  such
data,  certificates,  reports,  statements,  documents  or  further  information
regarding the business, assets,  liabilities,  financial position,  projections,
results of  operations  or  business  prospects  of the  Borrower  or any of its
Restricted  Subsidiaries,  as  Administrative  Agent or any Bank may  reasonably
request.

                   (d) Annually,  certificates of insurance  indicating that the
requirements  of Section  5.5 hereof  remain  satisfied  for such  fiscal  year,
together  with  copies of any new or  replacement  insurance  policies  obtained
during such year.

                   (e) Prior to January 31 of each year,  the annual  budget for
the Borrower and the Borrower's Restricted Subsidiaries,  including forecasts of
the income statement, the balance sheet and a cash flow statement for such year,
on a quarter by quarter basis.

                   (f)  Promptly  after  the  sending  thereof,  copies  of  all
statements,  reports  and other  information  which the  Borrower  or any of its
Restricted  Subsidiaries  sends  to  public  security  holders  of the  Borrower
generally or files with the Securities  and Exchange  Commission or any national
securities exchange.

         Section 6.5 Notice of Litigation and Other Matters.  Notice  specifying
the nature and status of any of the following events, promptly, but in any event
not later than fifteen (15) days after the  occurrence  of any of the  following
events becomes known to the Borrower:                                   

                   (a) the commencement of all proceedings and investigations by
or before any governmental  body and all actions and proceedings in any court or
before any arbitrator against the Borrower or any Restricted Subsidiary,  or, to
the extent known to the Borrower, which could have a Material Adverse Effect;

                  (b) any material  adverse change with respect to the business,
assets,  liabilities,  financial  position,  results of  operations  or business
prospects  of the Borrower and its  Restricted  Subsidiaries,  taken as a whole,
other than  changes in the  ordinary  course of 


                                    -52-
<PAGE>

business  which  have not had and would not  reasonably  be  expected  to have a
Materially  Adverse  Effect and other  than  changes  in the  industry  in which
Borrower  or  any  of  its  Restricted  Subsidiaries  operate  which  would  not
reasonably be expected to have a Material Adverse Effect;

                  (c)  any   material   adverse   amendment  or  change  to  the
projections or annual budget provided to the Banks by the Borrower;

                  (d) any Default or the  occurrence  or  non-occurrence  of any
event (i) which  constitutes,  or which  with the  passage  of time or giving of
notice or both would  constitute,  a default by the  Borrower or any  Restricted
Subsidiary  of the  Borrower  under  any  material  agreement  other  than  this
Agreement and the other Loan  Documents to which the Borrower or any  Restricted
Subsidiary  of the  Borrower  is  party  or by  which  any of  their  respective
properties may be bound,  or (ii) which could have a Materially  Adverse Effect,
giving in each case a description  thereof and specifying the action proposed to
be taken with respect thereto;

                  (e) the  occurrence of any  Reportable  Event or a "prohibited
transaction" (as such term is defined in Section 406 of ERISA or Section 4975 of
the Code) with respect to any Plan of the Borrower or any of its Subsidiaries or
the institution or threatened  institution by PBGC of proceedings under ERISA to
terminate  or to  partially  terminate  any  such  Plan or the  commencement  or
threatened  commencement of any litigation  regarding any such Plan or naming it
or the trustee of any such Plan with respect to such Plan or any action taken by
the  Borrower,  any  Subsidiary  of the  Borrower or any ERISA  Affiliate of the
Borrower to withdraw or partially  withdraw  from any Plan or to  terminate  any
Plan; and

                   (f) the  occurrence of any event  subsequent to the Agreement
Date which, if such event had occurred prior to the Agreement  Date,  would have
constituted an exception to the representation and warranty in Section 4.1(m) of
this Agreement.

         Section 6.6 Real Estate.  Within  seventy (70) days from  closing,  and
thereafter  at the time the Borrower  delivers its  financial  statements  under
Sections 6.1 and 6.2 hereof,  the Borrower  shall provide to the  Administrative
Agent a schedule  setting  forth the  annual  revenues  generated  by each owned
parcel of real estate and  indicating  that parcels  representing  not less than
seventy-five percent (75%) of such revenues are encumbered by mortgages in favor
of the Administrative Agent and the Banks.


                          ARTICLE 7 Negative Covenants

         So long as any of the  Obligations  is  outstanding  and  unpaid or the
Banks  have  an  obligation  to  fund  Advances  hereunder  (whether  or not the
conditions to borrowing  have 

                                       -53-
<PAGE>


been or can be fulfilled) and unless the Majority  Banks, or such greater number
of Banks as may be expressly  provided herein,  shall otherwise give their prior
consent in writing:

         Section 7.1  Indebtedness  of the  Borrower and its  Subsidiaries.  The
Borrower  shall not, and shall not permit any of its  Subsidiaries  to,  create,
assume,  incur or otherwise  become or remain obligated in respect of, or permit
to be outstanding, any Indebtedness except:                                   

                   (a) the Obligations;

                   (b) accounts payable,  accrued expenses (including taxes) and
customer advance payments incurred in the ordinary course of business;

                   (c) Indebtedness secured by Permitted Liens;

                   (d) obligations  under Interest Hedge Agreements with respect
to the Loans;

                   (e)  Indebtedness  of the  Borrower or any of its  Restricted
Subsidiaries to the Borrower or any other  Restricted  Subsidiary so long as the
corresponding  debt  instruments  are  pledged  to the  Administrative  Agent as
security  for the  Obligations  and such  Indebtedness  is  expressly  permitted
pursuant to Section 7.5 hereof;

                   (f)  Indebtedness  incurred by any  Unrestricted  Subsidiary;
provided that such  Indebtedness  is  non-recourse to the Borrower or any of its
Restricted  Subsidiaries  and no Lien is placed on the  Borrower's or any of its
Restricted Subsidiaries' equity interests in such Unrestricted Subsidiary;

                   (g)  Capitalized  Lease  Obligations  not  to  exceed  in the
aggregate at any one time outstanding $1,000,000; and

                   (h)  Indebtedness  of the  Borrower or any of its  Restricted
Subsidiaries incurred in connection with an Acquisition;  provided that (i) such
Indebtedness  (A) is owed to the seller  thereof,  (B) is unsecured,  (C) has no
scheduled payment of principal prior to the full payment of the Obligations, (D)
is  subject  to terms and  conditions  and  subordination  provisions  which are
acceptable to the Majority  Banks on the date of  incurrence,  (E) when added to
all other  Indebtedness  outstanding  under this Section  7.1(h) does not exceed
$5,000,000  and  (ii)  the  Borrower  is,  at the  time  of  incurrence  of such
Indebtedness  (and after giving effect thereto) in pro forma compliance with all
of the covenants contained in this Agreement.

         Section 7.2 Limitation on Liens.  The Borrower shall not, and shall not
permit any of its Restricted Subsidiaries to, create, assume, incur or permit to
exist or to be created,

                                       -54-
<PAGE>


assumed, incurred or permitted to exist, directly or indirectly, any Lien on any
of its properties or assets, whether now owned or hereafter acquired, except for
Permitted Liens.                                   

         Section 7.3 Amendment and Waiver. The Borrower shall not, and shall not
permit any of its  Restricted  Subsidiaries  to, enter into any amendment of, or
agree to or accept or consent to any waiver of any of the material provisions of
its articles or  certificate  of  incorporation  or  partnership  agreement,  as
appropriate,  if the effect  thereof would be to adversely  affect the rights of
the Banks hereunder or under any Loan Document.

         Section 7.4 Liquidation, Merger or Disposition of Assets.
                                  
                  (a)  Disposition of Assets.  The Borrower shall not, and shall
not  permit any of its  Restricted  Subsidiaries  to, at any time  sell,  lease,
abandon,  or otherwise  dispose of any assets (other than assets  disposed of in
the ordinary course of business) without the prior written consent of the Banks;
provided,  however,  that the prior  written  consent of the Banks  shall not be
required for (i) the  transfer of assets  (including  cash or cash  equivalents)
among the  Borrower  and its  Restricted  Subsidiaries  (excluding  Subsidiaries
described in clause (b) of the definition of  "Subsidiary")  or for the transfer
of assets  (including  cash or cash  equivalents)  between  or among  Restricted
Subsidiaries  (excluding  Subsidiaries described in clause (b) of the definition
of "Subsidiary") of the Borrower,  (ii) the disposition of communications  tower
facilities that contribute in the aggregate,  less than (A) five percent (5%) of
the  Operating  Cash Flow of  Borrower  for the  twelve  calendar  month  period
immediately  preceding such  disposition,  and (B) fifteen  percent (15%) of the
Operating  Cash Flow of the  Borrower  for the period  from the  Agreement  Date
through the date of such disposition, or (iii) subject to Section 2.5(c) hereof,
any other  property  (real or personal) not used or useful in Borrower's or such
Restricted  Subsidiary's  business;  provided  that, in each case, no Default or
Event of Default  exists and none shall be caused to occur as a result  thereof.
Upon any sale or disposition of a Restricted Subsidiary permitted hereunder, the
Administrative  Agent and the Banks  shall,  at  Borrower's  expense,  take such
actions as the Borrower reasonably requests to cause such Restricted  Subsidiary
to be released from its obligations under the Subsidiary Guaranty.

                  (b)  Liquidation or Merger.  The Borrower shall not, and shall
not permit any of its  Restricted  Subsidiaries  to, at any time,  liquidate  or
dissolve itself (or suffer any liquidation or dissolution) or otherwise wind up,
or enter into any  merger,  other than (i) a merger or  consolidation  among the
Borrower and one or more Restricted  Subsidiaries,  provided the Borrower is the
surviving corporation,  or (ii) a merger between or among two or more Restricted
Subsidiaries,  or (iii) in connection  with an Acquisition  permitted  hereunder
effected by a merger in which the Borrower or, in a merger in which the Borrower
is not a party,  a Restricted  Subsidiary  is the surviving  corporation  or the
surviving  corporation becomes a Restricted  Subsidiary;  provided that, in each
case, no Default or Event of Default exists and none shall be caused to occur as
a result thereof.

                                       -55-
<PAGE>


         Section 7.5 Limitation on Guaranties. The Borrower shall not, and shall
not permit any of its Restricted Subsidiaries to, at any time Guaranty,  assume,
be obligated with respect to, or permit to be  outstanding  any Guaranty of, any
obligation  of any other  Person  other than (a) a guaranty  by  endorsement  of
negotiable instruments for collection in the ordinary course of business, or (b)
obligations   under  agreements  of  the  Borrower  or  any  of  its  Restricted
Subsidiaries  entered into in connection with Acquisitions  permitted under this
Agreement  leases of real property or the acquisition of services,  supplies and
equipment  in the  ordinary  course of  business  of the  Borrower or any of its
Restricted Subsidiaries, or (c) Guaranties of Indebtedness incurred as permitted
pursuant to Section 7.1 hereof,  or (d) as may be contained in any Loan Document
including, without limitation, any Subsidiary Guaranty.

         Section 7.6 Investments and  Acquisitions.  The Borrower shall not, and
shall not permit any of its Restricted  Subsidiaries  to, directly or indirectly
make any loan or advance,  or otherwise acquire for  consideration  evidences of
Indebtedness, capital stock or other securities of any Person or other assets or
property (other than assets or property in the ordinary course of business),  or
make any Acquisition,  except that so long as no Default then exists or would be
caused thereby:                                    

                  (a) The Borrower and its Restricted Subsidiaries may, directly
or through a brokerage account (i) purchase  marketable,  direct  obligations of
the United States of America, its agencies and instrumentalities maturing within
three  hundred  sixty-five  (365) days of the date of  purchase,  (ii)  purchase
commercial  paper,  money-market  funds and business  savings accounts issued by
corporations,  each of  which  shall  have a  combined  net  worth  of at  least
$100,000,000  and each of which  conducts a substantial  part of its business in
the United  States of America,  maturing  within two hundred  seventy (270) days
from the date of the  original  issue  thereof,  and  rated  "P-2" or  better by
Moody's  Investors  Service,  Inc.  or "A-2" or better by  Standard  and  Poor's
Ratings Group, a division of McGraw-Hill,  (iii) purchase repurchase agreements,
bankers'  acceptances,  and  domestic  and  Eurodollar  certificates  of deposit
maturing  within  three  hundred  sixty-five  (365) days of the date of purchase
which are issued by, or time deposits  maintained with, a United States national
or state bank the deposits of which are insured by the Federal Deposit Insurance
Corporation  or the Federal  Savings and Loan Insurance  Corporation  and having
capital, surplus and undivided profits totaling more than $100,000,000 and rated
"A" or better by Moody's Investors Service,  Inc. or Standard and Poor's Ratings
Group, a division of McGraw-Hill, Inc.;

                  (b)  Subject to  compliance  with  Section  5.14  hereof,  the
Borrower or any of its Restricted  Subsidiaries may (i) make Acquisitions;  (ii)
initiate  construction of new  communications  tower facilities;  and (iii) make
investments  in  Unrestricted  Subsidiaries  so long as (A) the  maximum  amount
expended to acquire tower management  businesses and site  acquisitions does not
exceed  $25,000,000 in the aggregate,  (B) the maximum amount of 

                                       -56-
<PAGE>


the  proceeds  of the Loans  invested  in or used to  acquire  interests  in any
Unrestricted  Subsidiary  does  not  exceed  the sum of (1)  $13,500,000  in the
aggregate  during the term hereof and (2) to the extent not used for  Restricted
Payments,  funds  permitted  to be used  for  Restricted  Payments  pursuant  to
Sections  7.7(a) and (b) hereof,  provided that proceeds from the disposition of
any such investment permitted by this clause (b)(iii),  shall be available to be
used  for  Restricted  Payments  or to  make  additional  investments  permitted
hereunder;  provided,  further,  that  Borrower may,  subject to Section  2.5(d)
hereof,  use the Net Proceeds of any  issuance of equity  interests to invest in
any  Unrestricted  Subsidiary  over and above the  limitations set forth in this
clause (b) and (C) the  contribution  to the Operating Cash Flow of the Borrower
at the time of such investment of all such  Unrestricted  Subsidiaries  does not
exceed fifteen percent (15%) of the Operating Cash Flow of the Borrower; and

                   (c) Loans or advances to  OPM-USA-Inc.,  as  contemplated  by
that Stock  Purchase  Agreement  between the  Borrower and  OPM-USA-Inc.  not to
exceed  $9,000,000  (so long as such  loans  and  advances  are  evidenced  by a
promissory note).

         Section 7.7 Restricted Payments.  The Borrower shall not, and shall not
permit any of its Restricted  Subsidiaries to, directly or indirectly declare or
make any  Restricted  Payment;  provided,  however,  that so long as no  Default
hereunder  then exists or would be caused  thereby,  the  Borrower  may make (a)
subject to Section 2.5(b)  hereof,  (i) cash  distributions  in an amount not to
exceed fifty  percent  (50%) of Excess Cash Flow for the  immediately  preceding
calendar  year, on or after April 15 of each  calendar year  commencing on April
15,  2000 less (ii) any  portion  thereof  used for  purposes  of  investing  in
Unrestricted  Subsidiaries;  (b) (i) cash distributions from fifty percent (50%)
of the net proceeds of any equity  offering  less (ii) any portion  thereof used
for  purposes of  investing  in  Unrestricted  Subsidiaries,  subject to Section
2.5(d) hereof and so long as the Leverage Ratio on such date is less than 4.0 to
1 after giving effect to any payment pursuant to Section  2.7(b)(iv) hereof; and
(c)  interest  payments on  Indebtedness  incurred  pursuant  to Section  7.1(h)
hereof.

         Section 7.8 Leverage Ratio.

                   (a) As of the  end of any  calendar  quarter,  and (b) at the
time of any  Advance  hereunder  (after  giving  effect  to such  Advance),  the
Borrower  shall not  permit  its  Leverage  Ratio to exceed the ratios set forth
below during the periods indicated:

                                       -57-
<PAGE>

                            Period                                Ratio
                            ------                                -----

         Agreement Date through September 29, 1999                6.00:1

         September 30, 1999 through March 30, 2000                5.50:1

         March 31, 2000 through September 29, 2000                5.00:1

         September 30, 2000 through March 30, 2001                4.50:1

         March 31, 2001 through December 30, 2001                 4.00:1

         December 31, 2001 through December 30, 2002              3.50:1

         December 31, 2002 and thereafter                         3.00:1

         Section 7.9 Interest  Coverage Ratio. The Borrower and its consolidated
Restricted  Subsidiaries shall maintain,  on a consolidated  basis, at all times
during the applicable  periods set forth below,  an Interest  Coverage Ratio for
such  fiscal  quarter of not less than the ratio set forth below  opposite  each
such period:
                                   
                           Period                                Ratio
                           ------                                -----

         Agreement Date through September 29, 2000               2.00:1

         September 30, 2000 and thereafter                       2.50:1

         Section 7.10 Annualized Operating Cash Flow to Pro Forma Debt Service.
                                   

                   (a) As of the  end of any  calendar  quarter,  and (b) at the
time of any  Advance  hereunder  (after  giving  effect  to such  Advance),  the
Borrower  shall not permit the ratio of (i) its  Annualized  Operating Cash Flow
(for the calendar  quarter/month end being tested in the case of Section 7.10(a)
hereof, or for the most recently  completed  calendar  quarter/month end, in the
case of Section  7.10(b)  hereof) to (ii) its Pro Forma Debt  Service to be less
than the ratio set forth below opposite each such period:

                            Period                                Ratio
                            ------                                -----
         Agreement Date through September 29, 2000               1.10:1

         September 30, 2000 and thereafter                       1.15:1

                                       -58-
<PAGE>


         Section 7.11  Limitation on Capital  Expenditures.  The Borrower,  on a
consolidated  basis  with its  Restricted  Subsidiaries,  shall not  permit  its
Capital  Expenditures  to exceed the  amounts  set forth  below for the  periods
indicated:
                                   
                           Period                               Dollar Amount
                            ------                              -------------

         From January 1, 1997 through December 31, 1997           $15,000,000

         From January 1, 1998 through December 31, 1998           $22,000,000

         From January 1, 1999 through December 31, 1999           $10,000,000

         From January 1, 2000 through December 31, 2000           $ 5,000,000
         and each calendar year period thereafter

To the extent not used in any  calendar  year,  an amount equal to the lesser of
(a) the unused amounts permitted for Capital Expenditures for such calendar year
and (b) fifteen  percent (15%) of the maximum Capital  Expenditure  availability
for such calendar year may (exclusive of any  carryforwards  from prior periods)
be carried  forward to the next calendar  year,  and may be spent in addition to
the otherwise applicable limitations for such year.

         Section 7.12 Affiliate  Transactions.  Except as specifically  provided
herein (including,  without limitation,  Sections 7.4 and 7.7 hereof) and as may
be described on Schedule  4.1(s)  attached  hereto,  the Borrower shall not, and
shall not permit any of its  Restricted  Subsidiaries  to, at any time engage in
any  transaction  with an Affiliate,  or make an assignment or other transfer of
any of its properties or assets to any Affiliate,  on terms less advantageous to
the  Borrower  or such  Restricted  Subsidiary  than  would  be the case if such
transaction had been effected with a non-Affiliate.

         Section 7.13 Real Estate.  Subject to Section 5.11 hereof, the Borrower
and its Restricted  Subsidiaries  may purchase real estate solely for use in the
business of the Borrower and its Restricted Subsidiaries unless incidental to an
Acquisition permitted hereunder.                                    

         Section 7.14 ERISA Liabilities. The Borrower shall not, and shall cause
each of its ERISA  Affiliates  not to,  (a)  permit  the  assets of any of their
respective  Plans to be less than the amount  necessary  to provide  all accrued
benefits under such Plans, or (b) enter into any Multiemployer Plan.       

         Section 7.15 Sales and  Leasebacks.  The Borrower will not and will not
permit  any of its  Restricted  Subsidiaries  to enter  into,  any  arrangement,
directly  or  indirectly,  with  any  third  party  whereby  the  Borrower  or a
Restricted  Subsidiary  shall sell or transfer any  

                                       -59-
<PAGE>

property, real or personal, whether now owned or hereafter acquired, and whereby
the Borrower or such  Restricted  Subsidiary  shall then or  thereafter  rent or
lease as lessee such  property or any part thereof or other  property  which the
Borrower or such Restricted Subsidiary intends to use for substantially the same
purpose or purposes as the property sold or transferred.

                               ARTICLE 8 Default

         Section 8.1 Events of Default.  Each of the following shall  constitute
an Event of Default,  whatever the reason for such event and whether it shall be
voluntary or  involuntary  or be effected by operation of law or pursuant to any
judgment  or  order  of any  court  or any  order,  rule  or  regulation  of any
governmental or non-governmental body:                                    

                   (a) Any  representation or warranty made under this Agreement
shall prove incorrect or misleading in any material  respect when made or deemed
to be made pursuant to Section 4.2 hereof;

                   (b) The  Borrower  shall  default  in the  payment of (i) any
interest  under any of the Notes or fees or other  amounts  payable to the Banks
and the  Administrative  Agent under any of the Loan Documents,  or any of them,
when due,  and such  Default  shall not be cured by payment in full within three
(3) Business Days from the due date or (ii) any principal under any of the Notes
when due;

                   (c)  The  Borrower  shall  default  in  the   performance  or
observance  of any  agreement or covenant  contained in Sections  5.2(a) or 5.10
hereof, or Sections 7.1, 7.2, 7.4, 7.5, 7.7, 7.8, 7.9, 7.10 and 7.11 hereof;

                  (d)  The  Borrower   shall  default  in  the   performance  or
observance of any other  agreement or covenant  contained in this  Agreement not
specifically  referred to elsewhere in this Section 8.1, and such default  shall
not be curable  within a period of thirty (30) days (or with respect to Sections
5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 5.14,  5.15,  5.16, 6.4, 6.5, 7.3, 7.12, 7.13
and 7.14  hereof,  such  longer  period  not to exceed  sixty  (60) days if such
default is curable  within such period and the  Borrower is  proceeding  in good
faith  with all  diligent  efforts to cure such  default)  from the later of (i)
occurrence of such Default and (ii) the date on which such Default  became known
to the Borrower;

                  (e)  There  shall  occur any  default  in the  performance  or
observance  of any  agreement  or  covenant or breach of any  representation  or
warranty contained in any of the Loan Documents (other than this Agreement or as
otherwise provided in Section 8.1 of this Agreement) by the Borrower, any of its
Restricted  Subsidiaries,  or any other obligor  thereunder,  which shall not be
cured  within a period of thirty (30) days (or such longer  period not to exceed
sixty (60) days if such  default is curable  within such period and the 

                                       -60-
<PAGE>


Borrower  is  proceeding  in good faith with all  diligent  efforts to cure such
default) from the later of (i) occurrence of such Default and (ii) date on which
such default became known to the Borrower;

                  (f) There  shall be entered  and  remain  unstayed a decree or
order for relief in respect of the Borrower or any of the Borrower's  Restricted
Subsidiaries  under Title 11 of the United  States Code, as now  constituted  or
hereafter  amended,  or any other applicable  Federal or state bankruptcy law or
other  similar law, or  appointing a receiver,  liquidator,  assignee,  trustee,
custodian,  sequestrator  or  similar  official  of the  Borrower  or any of the
Borrower's  Restricted  Subsidiaries,  or  of  any  substantial  part  of  their
respective properties,  or ordering the winding-up or liquidation of the affairs
of  the  Borrower,  or  any of the  Borrower's  Restricted  Subsidiaries;  or an
involuntary  petition  shall  be  filed  against  the  Borrower  or  any  of the
Borrower's  Restricted  Subsidiaries and a temporary stay entered,  and (i) such
petition and stay shall not be diligently  contested,  or (ii) any such petition
and stay shall  continue  undismissed  for a period of ninety  (90)  consecutive
days;

                  (g)  The  Borrower  or  any  of  the   Borrower's   Restricted
Subsidiaries shall file a petition, answer or consent seeking relief under Title
11 of the United States Code, as now  constituted or hereafter  amended,  or any
other  applicable  Federal or state  bankruptcy law or other similar law, or the
Borrower or any of the Borrower's  Restricted  Subsidiaries shall consent to the
institution of  proceedings  thereunder or to the filing of any such petition or
to the appointment or taking of possession of a receiver, liquidator,  assignee,
trustee,  custodian,  sequestrator or other similar  official of the Borrower or
any of the Borrower's  Restricted  Subsidiaries  or of any  substantial  part of
their respective properties, or the Borrower or any of the Borrower's Restricted
Subsidiaries  shall fail generally to pay their  respective debts as they become
due or shall be adjudicated insolvent; the Borrower shall suspend or discontinue
its  business;  the Borrower or any of the  Borrower's  Restricted  Subsidiaries
shall have  concealed,  removed any of its property with the intent to hinder or
defraud its creditors or shall have made a fraudulent or  preferential  transfer
under any applicable fraudulent conveyance or bankruptcy law, or the Borrower or
any  of  the  Borrower's  Restricted  Subsidiaries  shall  take  any  action  in
furtherance of any such action;

                  (h) A judgment not covered by  insurance  or  indemnification,
where the indemnifying  party has agreed to indemnify and is financially able to
do so,  shall  be  entered  by any  court  against  the  Borrower  or any of the
Borrower's  Restricted  Subsidiaries  for the  payment  of money  which  exceeds
singly, or in the aggregate with other such judgments,  $1,000,000, or a warrant
of attachment or execution or similar  process shall be issued or levied against
property of the Borrower or any of the Borrower's Restricted Subsidiaries which,
together with all other such  property of the Borrower or any of the  Borrower's
Restricted  Subsidiaries  subject  to  other  such  process,  exceeds  in  value
$1,000,000  in the  aggregate,  and if, within thirty (30) days after the entry,
issue or levy  thereof,  such  judgment,  warrant or process shall not have been
paid or discharged or stayed pending appeal or 

                                       -61-
<PAGE>

removed to bond, or if, after the  expiration of any such stay,  such  judgment,
warrant or process shall not have been paid or discharged or removed to bond;

                  (i)  There  shall  be at any  time  any  "accumulated  funding
deficiency,"  as defined in ERISA or in Section 412 of the Code, with respect to
any Plan  maintained  by the  Borrower or any of its  Subsidiaries  or any ERISA
Affiliate,  or to which the  Borrower  or any of its  Subsidiaries  or any ERISA
Affiliate has any  liabilities,  or any trust created  thereunder;  or a trustee
shall be appointed by a United  States  District  Court to  administer  any such
Plan;  or PBGC shall  institute  proceedings  to terminate any such Plan; or the
Borrower  or any of its  Subsidiaries  or any ERISA  Affiliate  shall  incur any
liability to PBGC in connection  with the  termination  of any such Plan; or any
Plan or trust created under any Plan of the Borrower or any of its  Subsidiaries
or any ERISA Affiliate shall engage in a "prohibited  transaction" (as such term
is defined in Section  406 of ERISA or  Section  4975 of the Code)  which  would
subject  any  such  Plan,   any  trust  created   thereunder,   any  trustee  or
administrator  thereof,  or any party dealing with any such Plan or trust to the
tax or penalty on "prohibited  transactions"  imposed by Section 502 of ERISA or
Section 4975 of the Code;

                  (j) There shall occur (i) any  acceleration of the maturity of
any   Indebtedness  of  the  Borrower  or  any  of  the  Borrower's   Restricted
Subsidiaries in an aggregate  principal  amount exceeding  $1,000,000,  or, as a
result of a failure to comply with the terms thereof,  such  Indebtedness  shall
otherwise  have  become  due and  payable;  (ii)  any  event  or  condition  the
occurrence  of which would permit such  acceleration  of such  Indebtedness,  or
which,  as a result of a failure to comply  with the terms  thereof,  would make
such  Indebtedness  otherwise due and payable,  and which event or condition has
not been cured within any  applicable  cure period or waived in writing prior to
any declaration of an Event of Default or  acceleration of the Loans  hereunder;
or (iii) any material  default under any Interest  Hedge  Agreement  which would
permit the  obligation  of the  Borrower to make  payments  to the  counterparty
thereunder to be then due and payable;

                   (k) The Borrower and its Restricted  Subsidiaries are for any
reason no longer  able to  operate or manage the  related  communications  tower
facilities or portions  thereof and retain the revenue received  therefrom,  and
the overall effect of such loss, destruction, termination, revocation or failure
to renew would be to reduce  Operating Cash Flow  (determined as at the last day
of the most recently  ended fiscal year of the Borrower) by ten percent (10%) or
more;

                  (1) Any material  Loan  Document,  or any  material  provision
thereof,  shall  at any  time  and for any  reason  be  declared  by a court  of
competent  jurisdiction to be null and void, or a proceeding  shall be commenced
by the  Borrower  or any of the  Borrower's  Restricted  Subsidiaries  or by any
governmental  authority  having  jurisdiction  over the  Borrower  or any of the
Borrower's  Restricted  Subsidiaries  seeking to  establish  the  invalidity  or
unenforceability  thereof  (exclusive  of  questions  of  interpretation  of any
provision thereof),

                                       -62-
<PAGE>

or the Borrower or any of the Borrower's Subsidiaries shall deny that it has any
liability or obligation for the payment of principal or interest purported to be
created under any Loan Document;

                   (m) Any material  Security  Document  shall,  for any reason,
fail or cease  (except  by  reason  of lapse  of  time)  to  create a valid  and
perfected  and  first-priority  Lien on or  Security  Interest  in any  material
portion of the Collateral purported to be covered thereby;

                   (n) There  shall  occur  any  Change  of  Control;  provided,
however,  that if such  Change of Control is solely a result of  American  Radio
Systems no longer owning 51% of the Capital  Stock of the Borrower,  no Event of
Default  shall occur  hereunder,  if the Borrower has, on or prior to such date,
received equity  contributions of not less than  $125,000,000 (of which not less
than $100,000,000 must be in cash or cash equivalents) in the aggregate;      

                   (o) Borrower or any of its Restricted  Subsidiaries  shall be
indicted under the Racketeer  Influenced and Corrupt  Organizations  Act of 1970
(18 U.S.C.ss.1961 et seq.); or

                  (p) The Parent shall incur or suffer to exist any Indebtedness
for Money Borrowed other than Indebtedness for Money Borrowed which (i) does not
exceed  $50,000,000  in  principal  amount  outstanding  (ii)  has no  scheduled
principal  repayment prior to the Maturity Date, (iii) has a scheduled  maturity
not earlier  than the second  anniversary  of the Maturity  Date,  (iv) does not
cause the ratio of  Indebtedness  of the Borrower  and the Parent to  Annualized
Operating  Cash Flow to exceed  7.0:1 and (v) is approved in all respects by the
Majority Banks.

         Section 8.2 Remedies.

                  (a) If an Event of Default  specified  in  Section  8.1 (other
than an Event of Default under Section  8.1(f) or Section  8.1(g)  hereof) shall
have occurred and shall be continuing,  the Administrative Agent, at the request
of the Majority Banks subject to Section 9.8(a) hereof,  shall (i) terminate the
Commitment,  and/or (ii) declare the  principal of and interest on the Loans and
the Notes and all other amounts owed to the Banks and the  Administrative  Agent
under this Agreement, the Notes and any other Loan Documents to be forthwith due
and payable without  presentment,  demand,  protest or other notice of any kind,
all of which are hereby expressly waived, anything in this Agreement,  the Notes
or any other Loan Document to the contrary  notwithstanding,  and the Commitment
shall thereupon forthwith terminate.

                  (b) Upon the occurrence and continuance of an Event of Default
specified in Section 8.1(f) or Section 8.1(g)  hereof,  all principal,  interest
and other amounts due 

                                       -63-
<PAGE>


hereunder and under the Notes,  and all other  Obligations,  shall thereupon and
concurrently therewith become due and payable and the Commitment shall forthwith
terminate and the principal amount of the Loans outstanding hereunder shall bear
interest at the Default Rate, all without any action by the Administrative Agent
or the  Banks or the  Majority  Banks or any of them  and  without  presentment,
demand,  protest or other notice of any kind, all of which are expressly waived,
anything  in this  Agreement  or in the other  Loan  Documents  to the  contrary
notwithstanding.

                   (c) Upon acceleration of the Notes, as provided in subsection
(a) or (b) of this  Section 8.2,  the  Administrative  Agent and the Banks shall
have  all of the  post-default  rights  granted  to  them,  or any of  them,  as
applicable under the Loan Documents and under Applicable Law.

                   (d) Upon acceleration of the Notes, as provided in subsection
(a) or (b) of this Section 8.2,  the  Administrative  Agent shall have the right
(but  not  the  obligation)  upon  the  request  of the  Banks  to  operate  the
communications tower facilities of the Borrower and its Restricted  Subsidiaries
in  accordance  with the terms of the  Licenses  and  pursuant  to the terms and
subject to any  limitations  contained in the  Security  Documents  and,  within
guidelines  established by the Majority  Banks, to make any and all payments and
expenditures necessary or desirable in connection therewith,  including, without
limitation,  payment of wages as required under the Fair Labor Standards Act, as
amended, and of any necessary withholding taxes to state or federal authorities.
In the event the Majority Banks fail to agree upon the guidelines referred to in
the preceding  sentence  within six (6) Business Days' after the  Administrative
Agent  has  begun  to  operate  the   communications   tower   facilities,   the
Administrative  Agent may,  after giving three (3) days' prior written notice to
the Banks of its intention to do so, make such payments and  expenditures  as it
deems  reasonable  and  advisable in its sole  discretion to maintain the normal
day-to-day operation of such communications tower facilities.  Such payments and
expenditures  in  excess  of  receipts  shall  constitute   Advances  under  the
Commitment,  not in  excess  of the  amount  of the  Commitment.  Advances  made
pursuant  to this  Section  8.2(d)  shall bear  interest  as provided in Section
2.3(d) hereof and shall be payable on demand. The making of one or more Advances
under this  Section  8.2(d) shall not create any  obligation  on the part of the
Banks  to  make  any  additional   Advances   hereunder.   No  exercise  by  the
Administrative Agent of the rights granted to it under this Section 8.2(d) shall
constitute  a  waiver  of  any  other   rights  and  remedies   granted  to  the
Administrative  Agent and the Banks, or any of them,  under this Agreement or at
law. The Borrower hereby irrevocably  appoints the Administrative Agent as agent
for the Banks,  the true and lawful  attorney of the  Borrower,  in its name and
stead and on its behalf, to execute,  receipt for or otherwise act in connection
with any and all contracts,  instruments or other  documents in connection  with
the  completion  and  operation of the  communications  tower  facilities in the
exercise of the Administrative  Agent's and the Banks' rights under this Section
8.2(d).  Such power of attorney is coupled with an interest and is  irrevocable.
The rights of the  Administrative  Agent  under  this  Section  8.2(d)  shall be

                                      -64-
<PAGE>


subject to its prior  compliance with the  Communications  Act and the FCC rules
and policies promulgated  thereunder to the extent applicable to the exercise of
such rights.

                   (e) Upon acceleration of the Notes, as provided in subsection
(a) or (b) of this Section 8.2, the  Administrative  Agent,  upon request of the
Majority  Banks,  shall have the right to the  appointment of a receiver for the
properties and assets of the Borrower and its Restricted  Subsidiaries,  and the
Borrower,  for  itself  and on behalf  of its  Restricted  Subsidiaries,  hereby
consents to such rights and such appointment and hereby waives any objection the
Borrower or any  Restricted  Subsidiary  may have thereto or the right to have a
bond or other  security  posted  by the  Administrative  Agent on  behalf of the
Banks, in connection  therewith.  The rights of the  Administrative  Agent under
this  Section  8.2(e)  shall  be  subject  to  its  prior  compliance  with  the
Communications Act and the FCC rules and policies promulgated  thereunder to the
extent applicable to the exercise of such rights.

                   (f) The rights and remedies of the  Administrative  Agent and
the Banks hereunder shall be cumulative, and not exclusive.

         Section 8.3 Payments  Subsequent  to  Declaration  of Event of Default.
Subsequent to the  acceleration of the Loans under Section 8.2 hereof,  payments
and prepayments  under this Agreement made to the  Administrative  Agent and the
Banks  or  otherwise  received  by any of  such  Persons  (from  realization  on
Collateral  for  the  Obligations  or  otherwise)  shall  be  paid  over  to the
Administrative  Agent (if necessary) and distributed by the Administrative Agent
as follows:  first, to the Administrative Agent's reasonable costs and expenses,
if  any,  incurred  in  connection  with  the  collection  of  such  payment  or
prepayment,  including,  without limitation, any reasonable costs incurred by it
in connection with the sale or disposition of any Collateral for the Obligations
and all amounts under Section  11.2(b) and (c) hereof;  second,  to the Banks or
the  Administrative  Agent for any fees hereunder or under any of the other Loan
Documents  then due and  payable;  third,  to the Banks pro rata on the basis of
their respective  unpaid principal amounts (except as provided in Section 2.2(e)
hereof),  to the payment of any unpaid  interest  which may have  accrued on the
Obligations;  fourth,  to the Banks pro rata  until all Loans  have been paid in
full (and,  for  purposes  of this  clause,  obligations  under  Interest  Hedge
Agreements  with the Banks or any of them shall be paid on a pro rata basis with
the Loans); fifth, to the Banks pro rata on the basis of their respective unpaid
amounts,  to the  payment of any other  unpaid  Obligations;  and sixth,  to the
Borrower or as otherwise required by law.


                       ARTICLE 9 The Administrative Agent

         Section 9.1 Appointment and Authorization. Each Bank hereby irrevocably
appoints and  authorizes,  and hereby agrees that it will require any transferee
of any of its  interest in its portion of the Loans and in its Note  irrevocably
to appoint and authorize,  the

                                       -65-
<PAGE>

Administrative  Agent to take such  actions  as its agent on its  behalf  and to
exercise  such  powers  hereunder  and  under the other  Loan  Documents  as are
delegated  by the terms  hereof and  thereof,  together  with such powers as are
reasonably incidental thereto.  Neither the Administrative Agent, nor any of its
respective  directors,  officers,  employees or agents,  shall be liable for any
action  taken or omitted to be taken by it or them  hereunder  or in  connection
herewith,  except for its or their own gross negligence or willful misconduct as
determined  by a final,  non-appealable  judicial  order of a court of competent
jurisdiction.

         Section 9.2 Interest Holders.  The Administrative  Agent may treat each
Bank, or the Person designated in the last notice filed with the  Administrative
Agent,  as the holder of all of the interests of such Bank in its portion of the
Loans and in its Note until written notice of transfer,  signed by such Bank (or
the Person  designated in the last notice filed with the  Administrative  Agent)
and by the Person  designated  in such written  notice of transfer,  in form and
substance  satisfactory to the Administrative  Agent, shall have been filed with
the Administrative Agent.

         Section 9.3 Consultation  with Counsel.  The  Administrative  Agent may
consult with Powell,  Goldstein,  Frazer & Murphy LLP, Atlanta, Georgia, special
counsel to the Administrative  Agent, or with other legal counsel selected by it
and shall not be liable for any action  taken or suffered by it in good faith in
consultation  with  the  Majority  Banks  and in  reasonable  reliance  on  such
consultations.                   

         Section 9.4 Documents.  The Administrative Agent shall be under no duty
to  examine,  inquire  into,  or  pass  upon  the  validity,   effectiveness  or
genuineness  of this  Agreement,  any Note,  any  other  Loan  Document,  or any
instrument, document or communication furnished pursuant hereto or in connection
herewith, and the Administrative Agent shall be entitled to assume that they are
valid, effective and genuine, have been signed or sent by the proper parties and
are what they purport to be.      

         Section 9.5  Administrative  Agent and Affiliates.  With respect to the
Commitment and the Loans,  the  Administrative  Agent shall have the same rights
and  powers  hereunder  as any  other  Bank  and the  Administrative  Agent  and
Affiliates of the  Administrative  Agent may accept deposits from, lend money to
and  generally  engage in any kind of  business  with the  Borrower,  any of its
Subsidiaries or any Affiliates of, or Persons doing business with, the Borrower,
as if they were not  affiliated  with the  Administrative  Agent and without any
obligation to account therefor.

         Section 9.6 Responsibility of the Administrative  Agent. The duties and
obligations  of the  Administrative  Agent under this  Agreement  are only those
expressly  set  forth  in this  Agreement.  The  Administrative  Agent  shall be
entitled  to assume  that no  Default or Event of Default  has  occurred  and is
continuing  unless it has actual  knowledge,  or has been notified in writing by
the Borrower,  of such fact, or has been notified by a Bank in writing that such

                                       -66-
<PAGE>


Bank  considers  that a  Default  or an Event of  Default  has  occurred  and is
continuing, and such Bank shall specify in detail the nature thereof in writing.
The  Administrative  Agent shall not be liable hereunder for any action taken or
omitted to be taken except for its own gross negligence or willful misconduct as
determined  by a final,  non-appealable  judicial  order of a court of competent
jurisdiction.  The  Administrative  Agent shall provide each Bank with copies of
such documents received from the Borrower as such Bank may reasonably request.

         Section 9.7 Action by the Administrative Agent.                

                  (a) The  Administrative  Agent  shall be  entitled  to use its
discretion  with respect to exercising or refraining  from exercising any rights
which may be vested in it by,  and with  respect  to taking or  refraining  from
taking any  action or  actions  which it may be able to take under or in respect
of, this Agreement,  unless the Administrative  Agent shall have been instructed
by the Majority Banks to exercise or refrain from  exercising  such rights or to
take or refrain from taking such action;  provided that the Administrative Agent
shall not exercise any rights under Section 8.2(a) of this Agreement without the
request of the Majority Banks (or,  where  expressly  required,  all the Banks),
unless time is of the  essence,  in which case,  such action can be taken at the
request of the  Administrative  Agent. The  Administrative  Agent shall incur no
liability  under or in respect of this  Agreement with respect to anything which
it may do or refrain  from doing in the  reasonable  exercise of its judgment or
which may seem to it to be necessary or desirable in the  circumstances,  except
for its  gross  negligence  or  willful  misconduct  as  determined  by a final,
non-appealable  judicial order of a court having  jurisdiction  over the subject
matter.

                  (b) The Administrative  Agent shall not be liable to the Banks
or to any Bank or the Borrower or any of the Borrower's  Subsidiaries  in acting
or  refraining  from acting under this  Agreement or any other Loan  Document in
accordance  with the  instructions  of the Majority Banks (or,  where  expressly
required,  all the Banks),  and any action  taken or failure to act  pursuant to
such instructions shall be binding on all Banks, except for its gross negligence
or willful misconduct as determined by a final, non-appealable judicial order of
a court having  jurisdiction over the subject matter. The  Administrative  Agent
shall not be  obligated  to take any action  which is  contrary  to law or which
would in its reasonable opinion subject it to liability.

         Section  9.8 Notice of Default or Event of  Default.  In the event that
the  Administrative  Agent or any Bank shall acquire actual knowledge,  or shall
have been notified, of any Default or Event of Default, the Administrative Agent
or such Bank  shall  promptly  notify the Banks  (provided  failure to give such
notice  shall  not  result  in any  liability  on  the  part  of  such  Bank  or
Administrative  Agent), and the Administrative  Agent shall take such action and
assert such rights  under this  Agreement  and the other Loan  Documents  as the
Majority Banks shall request in writing,  and the Administrative Agent

                                       -67-
<PAGE>


shall not be subject to any  liability  by reason of its acting  pursuant to any
such  request.  If the Majority  Banks shall fail to request the  Administrative
Agent to take action or to assert rights under this  Agreement or any other Loan
Documents  in  respect of any  Default or Event of Default  within ten (10) days
after their  receipt of the notice of any  Default or Event of Default  from the
Administrative  Agent or any Bank,  or shall  request  inconsistent  action with
respect to such Default or Event of Default,  the Administrative  Agent may, but
shall not be required  to,  take such action and assert such rights  (other than
rights under Article 8 hereof) as it deems in its discretion to be advisable for
the protection of the Banks,  except that, if the Majority Banks have instructed
the  Administrative  Agent not to take such action or assert  such right,  in no
event shall the Administrative  Agent act contrary to such instructions,  unless
time is of the  essence,  in which  case,  the  Administrative  Agent may act in
accordance with its reasonable discretion.

         Section 9.9 Responsibility  Disclaimed.  The Administrative Agent shall
not be under any liability or responsibility whatsoever as Administrative Agent:
                                    
                   (a) To the Borrower or any other Person as a  consequence  of
any failure or delay in  performance  by, or any breach by, any Bank or Banks of
any of its or their obligations under this Agreement;

                   (b) To any Bank or Banks as a  consequence  of any failure or
delay in  performance  by, or any  breach  by,  (i) the  Borrower  of any of its
obligations  under this  Agreement or the Notes or any other Loan  Document,  or
(ii) any  Restricted  Subsidiary  of the Borrower or any other obligor under any
other Loan Document;

                   (c) To any Bank or Banks, for any statements, representations
or warranties in this  Agreement,  or any other  document  contemplated  by this
Agreement or any information provided pursuant to this Agreement, any other Loan
Document,  or any other  document  contemplated  by this  Agreement,  or for the
validity,  effectiveness,  enforceability or sufficiency of this Agreement,  the
Notes,  any other Loan  Document,  or any other  document  contemplated  by this
Agreement; or

                   (d) To any  Person  for any act or  omission  other than that
arising from gross negligence or willful misconduct of the Administrative  Agent
as determined by a final,  non-appealable judicial order of a court of competent
jurisdiction.

         Section  9.10  Indemnification.   The  Banks  agree  to  indemnify  the
Administrative  Agent (to the extent not  reimbursed  by the  Borrower) pro rata
according to their respective  Commitment  Ratios,  from and against any and all
liabilities,  obligations, losses (other than the loss of principal and interest
hereunder in the event of a bankruptcy or out-of-court 'work-out' of the Loans),
damages,  penalties,  actions, judgments, suits, costs, expenses (including fees
and expenses of experts,  agents,  consultants and counsel), or disbursements

                                       -68-
<PAGE>


of any kind or  nature  whatsoever  which  may be  imposed  on,  incurred  by or
asserted against the Administrative  Agent in any way relating to or arising out
of this Agreement,  any other Loan Document,  or any other document contemplated
by this  Agreement or any other Loan  Document or any action taken or omitted by
the Administrative Agent under this Agreement,  any other Loan Document,  or any
other  document  contemplated  by this  Agreement,  except that no Bank shall be
liable  to the  Administrative  Agent  for  any  portion  of  such  liabilities,
obligations,  losses,  damages,  penalties,  actions,  judgments,  suits, costs,
expenses,  or  disbursements  resulting  from the gross  negligence  or  willful
misconduct of the Administrative Agent as determined by a final,  non-appealable
judicial order of a court having jurisdiction over the subject matter.

         Section 9.11 Credit Decision. Each Bank represents and warrants to each
other and to the Administrative Agent that:
                                    
                  (a) In making its decision to enter into this Agreement and to
make its  portion  of the Loans it has  independently  taken  whatever  steps it
considers  necessary  to evaluate  the  financial  condition  and affairs of the
Borrower,  and that it has made an independent credit judgment,  and that it has
not  relied  upon  the  Administrative  Agent  or  information  provided  by the
Administrative  Agent  (other than  information  provided to the  Administrative
Agent by the Borrower and forwarded by the  Administrative  Agent to the Banks);
and

                   (b) So long as any portion of the Loans  remains  outstanding
or such Bank has an  obligation  to make its portion of Advances  hereunder,  it
will continue to make its own independent  evaluation of the financial condition
and affairs of the Borrower.

         Section 9.12 Successor Administrative Agent. Subject to the appointment
and  acceptance  of a  successor  Administrative  Agent as provided  below,  the
Administrative  Agent may resign at any time by giving written notice thereof to
the  Banks  and the  Borrower  and may be  removed  at any time for cause by the
Majority Banks.  Upon any such resignation or removal,  the Majority Banks shall
have the right to appoint a successor  Administrative  Agent  which  appointment
shall,  prior to a Default,  be subject to the consent of the  Borrower,  acting
reasonably.  If (a)  no  successor  Administrative  Agent  shall  have  been  so
appointed by the Majority Banks or (b) if appointed, no successor Administrative
Agent shall have  accepted  such  appointment  within thirty (30) days after the
retiring  Administrative  Agent gave notice of resignation or the Majority Banks
removed the retiring  Administrative  Agent,  then the  retiring  Administrative
Agent may,  on behalf of the Banks,  appoint a  successor  Administrative  Agent
which shall be any Bank or a  commercial  bank  organized  under the laws of the
United States of America or any political subdivision thereof which has combined
capital and  reserves in excess of  $250,000,000  and which shall be  reasonably
acceptable  to  the  Borrower.   Upon  the  acceptance  of  any  appointment  as
Administrative  Agent  hereunder  by  a  successor  Administrative  Agent,  such
successor Administrative Agent

                                       -69-
<PAGE>

shall  thereupon  succeed  to and become  vested  with all the  rights,  powers,
privileges,  duties and obligations of the retiring Administrative Agent and the
retiring   Administrative   Agent  shall  be  discharged  from  its  duties  and
obligations  hereunder  and under the other Loan  Documents.  After any retiring
Administrative  Agent's resignation or removal hereunder as Administrative Agent
the  provisions  of this  Article  shall  continue  in effect for its benefit in
respect of any actions taken or omitted to be taken by it while it was acting as
the Administrative  Agent. In the event that the Administrative  Agent or any of
its  respective  affiliates  ceases to be a Bank  hereunder,  such Person  shall
resign its agency hereunder.

         Section 9.13 Delegation of Duties. The Administrative Agent may execute
any of its duties  under the Loan  Documents  by or through  agents or attorneys
selected by it using reasonable care, and shall be entitled to advice of counsel
concerning all matters pertaining to such duties.                       


                      ARTICLE 10 Changes in Circumstances
                            Affecting LIBOR Advances

         Section 10.1 LIBOR Basis  Determination  Inadequate or Unfair.  If with
respect  to  any  proposed   LIBOR   Advance  for  any  Interest   Period,   the
Administrative  Agent determines after consultation with the Banks that deposits
in dollars (in the applicable amount) are not being offered to each of the Banks
in the relevant market for such Interest Period, the Administrative  Agent shall
forthwith give notice thereof to the Borrower and the Banks, whereupon until the
Administrative Agent notifies the Borrower that the circumstances giving rise to
such situation no longer exist, the obligations of any affected Bank to make its
portion of such LIBOR Advances shall be suspended.

         Section 10.2 Illegality.  If after the date hereof, the adoption of any
Applicable  Law, or any change in any Applicable Law (whether  adopted before or
after the Agreement  Date), or any change in  interpretation  or  administration
thereof by any governmental authority, central bank or comparable agency charged
with the  interpretation  or administration  thereof,  or compliance by any Bank
with  any  directive  (whether  or not  having  the  force  of law) of any  such
authority,  central  bank  or  comparable  agency,  shall  make it  unlawful  or
impossible for any Bank to make, maintain or fund its portion of LIBOR Advances,
such Bank shall so notify the Administrative Agent, and the Administrative Agent
shall forthwith give notice thereof to the other Banks and the Borrower.  Before
giving any notice to the  Administrative  Agent  pursuant to this Section  10.2,
such Bank shall designate a different  lending office if such  designation  will
avoid the need for  giving  such  notice  and will not,  in the sole  reasonable
judgment of such Bank,  be otherwise  materially  disadvantageous  to such Bank.
Upon receipt of such  notice,  notwithstanding  anything  contained in Article 2
hereof,  the Borrower shall repay in full the then outstanding  principal amount
of such Bank's  portion of each affected  LIBOR  Advance,  together with accrued
interest thereon, on either (a) the last

                                       -70-
<PAGE>

day of the then  current  Interest  Period  applicable  to such  affected  LIBOR
Advances if such Bank may lawfully  continue to maintain and fund its portion of
such LIBOR Advance to such day or (b)  immediately if such Bank may not lawfully
continue to fund and maintain  its portion of such  affected  LIBOR  Advances to
such day.  Concurrently  with  repaying  such  portion  of each  affected  LIBOR
Advance,  the Borrower may borrow a Base Rate Advance from such Bank, whether or
not it would have been  entitled  to effect such  borrowing  and such Bank shall
make such  Advance,  if so  requested,  in an amount  such that the  outstanding
principal  amount  of the  affected  Note  held by such  Bank  shall  equal  the
outstanding  principal  amount of such Note or Notes  immediately  prior to such
repayment.

         Section 10.3 Increased Costs.

                   (a) If after the date hereof,  the adoption of any Applicable
Law, or any change in any  Applicable  Law (whether  adopted before or after the
Agreement  Date),  or  any   interpretation   or  change  in  interpretation  or
administration thereof by any governmental authority, central bank or comparable
agency charged with the  interpretation or administration  thereof or compliance
by any Bank with any  directive  (whether or not having the force of law) of any
such authority, central bank or comparable agency:

                           (1) shall  subject any Bank to any tax, duty or other
         charge  with  respect to its  obligation  to make its  portion of LIBOR
         Advances,  or its portion of  existing  Advances,  or shall  change the
         basis  of  taxation  of  payments  to any Bank of the  principal  of or
         interest  on its  portion of LIBOR  Advances or in respect of any other
         amounts  due under this  Agreement,  in respect of its portion of LIBOR
         Advances  or its  obligation  to make its  portion  of  LIBOR  Advances
         (except for changes in the rate or method of  calculation of tax on the
         revenues or net income of such Bank); or

                           (2)  shall  impose,  modify  or deem  applicable  any
         reserve  (including,  without  limitation,  any imposed by the Board of
         Governors of the Federal Reserve System,  but excluding any included in
         an applicable Eurodollar Reserve Percentage),  special deposit, capital
         adequacy,  assessment or other  requirement or condition against assets
         of,  deposits  with or for the  account  of, or  commitments  or credit
         extended  by,  any  Bank or  shall  impose  on any  Bank or the  London
         interbank borrowing market any other condition affecting its obligation
         to make its  portion of such LIBOR  Advances or its portion of existing
         Advances;

and the result of any of the  foregoing  is to increase the cost to such Bank of
making or  maintaining  any of its portion of LIBOR  Advances,  or to reduce the
amount of any sum received or  receivable  by such Bank under this  Agreement or
under its Note with respect thereto,  then, within ten (10) days after demand by
such Bank,  the Borrower  agrees to pay to such Bank such  additional  amount or
amounts as will  compensate such Bank for such 

                                       -71-
<PAGE>

increased   costs.   Each  Bank  will  promptly  notify  the  Borrower  and  the
Administrative Agent of any event of which it has knowledge, occurring after the
date  hereof,  which will  entitle  such Bank to  compensation  pursuant to this
Section 10.3 and will designate a different  lending office if such  designation
will avoid the need for,  or reduce the amount of,  such  compensation  and will
not,  in the sole  reasonable  judgment  of such  Bank  made in good  faith,  be
otherwise disadvantageous to such Bank.

                  (b) Any Bank  claiming  compensation  under this  Section 10.3
shall  provide  the  Borrower  with a  written  certificate  setting  forth  the
additional  amount  or  amounts  to be paid  to it  hereunder  and  calculations
therefor in reasonable detail.  Such certificate shall be presumptively  correct
absent  manifest  error.  In  determining  such  amount,  such  Bank may use any
reasonable  averaging and attribution  methods. If any Bank demands compensation
under this Section  10.3,  the Borrower may at any time,  upon at least five (5)
Business Days' prior notice to such Bank,  prepay in full such Bank's portion of
the then  outstanding  LIBOR Advances,  together with accrued  interest and fees
thereon to the date of prepayment,  along with any reimbursement  required under
Section 2.10 hereof and this Section  10.3.  Concurrently  with  prepaying  such
portion of LIBOR Advances the Borrower may, whether or not then entitled to make
such borrowing,  borrow a Base Rate Advance, or a LIBOR Advance not so affected,
from such Bank,  and such Bank shall,  if so requested,  make such Advance in an
amount such that the outstanding  principal amount of the affected Note or Notes
held by such Bank shall equal the outstanding  principal  amount of such Note or
Notes immediately prior to such prepayment.

         Section  10.4  Effect  On Other  Advances.  If  notice  has been  given
pursuant to Section 10.1,  10.2 or 10.3 hereof  suspending the obligation of any
Bank to make its portion of any type of LIBOR Advance,  or requiring such Bank's
portion of LIBOR Advances to be repaid or prepaid,  then,  unless and until such
Bank notifies the Borrower that the circumstances  giving rise to such repayment
no longer apply,  all amounts which would  otherwise be made by such Bank as its
portion of LIBOR Advances shall,  unless otherwise notified by the Borrower,  be
made instead as Base Rate Advances.


                            ARTICLE 11 Miscellaneous

         Section 11.1 Notices.

                  (a) Except as otherwise expressly provided herein, all notices
and other  communications  under this  Agreement  and the other  Loan  Documents
(unless otherwise  specifically stated therein) shall be in writing and shall be
deemed to have been given  three (3)  Business  Days after  deposit in the mail,
designated as certified mail, return receipt requested,  postage-prepaid, or one
(1)  Business  Day after being  entrusted  to a reputable  commercial  overnight
delivery service for next day delivery,  or when sent on a Business Day 

                                       -72-
<PAGE>

prior to 5:00 p.m.  (New York time) by telecopy  addressed to the party to which
such notice is directed at its address  determined  as provided in this  Section
11.1. All notices and other  communications  under this Agreement shall be given
to the parties hereto at the following addresses:

                    (i)      If to the Borrower, to it at:

                             American Tower Systems, Inc.
                             116 Huntington Avenue
                             Boston, Massachusetts  02111
                             Attn:  Joseph B. Winn, Chief Financial Officer

                     with copies to:

                             Sullivan & Worcester LLP
                             One Post Office Square
                             Boston, Massachusetts 02110
                             Attn:  Norman A. Bikales, Esq.

                    (ii)     If to the Administrative Agent, to it at:

                             Toronto Dominion (Texas), Inc.
                             909 Fannin Street, Suite 1700
                             Houston, Texas 77010
                             Attention:  Agency Department

                     with a copy to:

                             The Toronto-Dominion Bank
                             Toronto Dominion Securities, Inc.
                             USA Division
                             31 West 52nd Street
                             New York, NY 10019-6101
                             Attn:  Managing Director, Communications Finance

                    and with a copy to:

                             Powell, Goldstein, Frazer & Murphy LLP
                             Sixteenth Floor
                             191 Peachtree Street, N.E.
                             Atlanta, Georgia  30303
                             Attn:  Douglas S. Gosden, Esq.

                                       -73-
<PAGE>


                           (iii) If to the Banks,  to them at the  addresses set
                  forth beside their names on the signature pages hereof.

The failure to provide  copies shall not affect the validity of the notice given
to the primary recipient.

                   (b) Any party hereto may change the address to which  notices
shall be  directed  under this  Section  11.1 by giving  ten (10) days'  written
notice of such change to the other parties.

         Section 11.2 Expenses. The Borrower will promptly pay, or reimburse:
                                    
                   (a)   all   reasonable    out-of-pocket   expenses   of   the
Administrative Agent in connection with the preparation,  negotiation, execution
and  delivery  of  this  Agreement  and  the  other  Loan  Documents,   and  the
transactions contemplated hereunder and thereunder and the making of the initial
Advance  hereunder  (whether or not such  Advance is made),  including,  but not
limited to, the reasonable fees and disbursements of Powell, Goldstein, Frazer &
Murphy LLP, special counsel for the Administrative Agent; and

                   (b) all  reasonable  out-of-pocket  costs and expenses of the
Administrative  Agent and the Banks of  enforcement  under this Agreement or the
other Loan  Documents  and all  reasonable  out-of-pocket  costs and expenses of
collection if an Event of Default  occurs in the payment of the Notes,  which in
each case shall include  reasonable fees and  out-of-pocket  expenses of counsel
for the Administrative Agent and the Banks.

         Section 11.3  Waivers.  The rights and  remedies of the  Administrative
Agent and the Banks under this Agreement and the other Loan  Documents  shall be
cumulative  and not  exclusive  of any  rights  or  remedies  which  they  would
otherwise have. No failure or delay by the  Administrative  Agent,  the Majority
Banks, or the Banks, or any of them, in exercising any right, shall operate as a
waiver of such right. The  Administrative  Agent and the Banks expressly reserve
the right to  require  strict  compliance  with the terms of this  Agreement  in
connection  with any future  funding of a Request for Advance.  In the event the
Banks decide to fund a Request for Advance at a time when the Borrower is not in
strict  compliance with the terms of this Agreement,  such decision by the Banks
shall  not be  deemed  to  constitute  an  undertaking  by the Banks to fund any
further  Request for Advance or preclude the Banks or the  Administrative  Agent
from  exercising  any rights  available  under the Loan  Documents  or at law or
equity. Any waiver or indulgence granted by the Administrative Agent, the Banks,
or the Majority Banks,  shall not constitute a modification of this Agreement or
any other Loan Document,  except to the extent expressly provided in such waiver
or  indulgence,  or constitute a course of dealing at variance with the terms of
this  Agreement or any other Loan 

                                       -74-
<PAGE>

Document  such as to require  further  notice of their intent to require  strict
adherence  to the terms of this  Agreement  or any other  Loan  Document  in the
future.

         Section  11.4  Set-Off.  In  addition  to any rights  now or  hereafter
granted  under  Applicable  Law and not by way of limitation of any such rights,
upon the occurrence of an Event of Default and during the continuation  thereof,
the  Administrative  Agent and each of the Banks are  hereby  authorized  by the
Borrower at any time or from time to time,  without notice to the Borrower or to
any other Person,  any such notice being hereby expressly waived, to set off and
to appropriate  and to apply any and all deposits  (general or special,  time or
demand, including, but not limited to, Indebtedness evidenced by certificates of
deposit,  in each case whether matured or unmatured) and any other  Indebtedness
at any time  held or owing by any Bank or  Administrative  Agent,  to or for the
credit or the  account of the  Borrower or any of its  Restricted  Subsidiaries,
against and on account of the obligations and liabilities of the Borrower to the
Banks  and  the  Administrative  Agent,  including,  but  not  limited  to,  all
Obligations and any other claims of any nature or description  arising out of or
connected  with  this   Agreement,   the  Notes  or  any  other  Loan  Document,
irrespective of whether (a) any Bank or Administrative Agent shall have made any
demand hereunder or (b) any Bank or Administrative Agent shall have declared the
principal of and interest on the Loans and other amounts due hereunder to be due
and payable as permitted by Section 8.2 hereof and although such obligations and
liabilities  or any of them shall be contingent or unmatured.  Upon direction by
the Administrative  Agent with the consent of all of the Banks each Bank holding
deposits of the Borrower or any of its  Restricted  Subsidiaries  shall exercise
its set-off  rights as so directed;  and,  within one (1) Business Day following
any such  setoff,  the  Administrative  Agent shall give  notice  thereof to the
Borrower.  Notwithstanding  anything to the  contrary  contained in this Section
11.4,  no Bank shall  exercise any right of offset  without the prior consent of
the  Majority  Banks so long as the  Obligations  shall be  secured  by any real
property or real property interest including  leaseholds located in the State of
California,  it being understood and agreed that the provisions of this sentence
are for the exclusive  benefit of the Banks, may be amended,  modified or waived
by the  Majority  Banks  without  notice to or  consent of the  Borrower  or any
Subsidiary  of the  Borrower  and shall not  constitute  a waiver of any  rights
against the Borrower or any Subsidiary or against any Collateral.

         Section 11.5 Assignment.

                   (a) The Borrower may not assign or transfer any of its rights
or  obligations  hereunder,  under the Notes or under  any other  Loan  Document
without the prior written consent of each Bank.

                  (b) Each Bank may sell (i)  assignments  of any  amount of its
interest  hereunder to any Bank, or (ii)  assignments or  participations  of one
hundred  percent  (100%)  (or,  with the  consent  of the  Borrower,  a  smaller
percentage)  of its  interest  hereunder  to (A) 

                                       -75-
<PAGE>

one (1) or more  wholly-owned  Affiliates of such Bank  (provided  that, if such
Affiliate  is not a  financial  institution,  such Bank  shall be  obligated  to
repurchase  such assignment if such Affiliate is unable to honor its obligations
hereunder),  or (B) any Federal Reserve Bank as collateral  security pursuant to
Regulation  A of the Board of Governors  of the Federal  Reserve  System and any
Operating  Circular  issued by such Federal  Reserve Bank (no  assignment  shall
relieve such Bank from its obligations hereunder).

                  (c) Each of the Banks may at any time  enter  into  assignment
agreements  or  participations  with one or more  other  banks or other  Persons
pursuant to which each Bank may assign or  participate  its interest  under this
Agreement  and  the  other  Loan  Documents,  including,  its  interest  in  any
particular Advance or portion thereof; provided, that (1) all assignments (other
than assignments  described in clause (b) hereof) shall be in minimum  principal
amounts  of the  lesser of (X)  $5,000,000,  and (Y) the  amount of such  Bank's
Commitment (in a single  assignment  only), and (2) all assignments  (other than
assignments  described in clause (b) hereof) and participations  hereunder shall
be subject to the following additional terms and conditions:

                           (i) No assignment  (except  assignments  permitted in
                  Section  11.5(b)  hereof)  shall  be sold  without  the  prior
                  consent  of  the   Administrative   Agent  and  prior  to  the
                  occurrence  and  continuation  of an  Event  of  Default,  the
                  consent  of  the  Borrower,   which   consents  shall  not  be
                  unreasonably withheld;

                           (ii) Any  Person  purchasing  a  participation  or an
                  assignment  of any portion of the Loans from any Bank shall be
                  required to represent and warrant that its purchase  shall not
                  constitute a "prohibited  transaction"  (as defined in Section
                  4.1(m) hereof);

                           (iii) The Borrower, the Banks, and the Administrative
                  Agent agree that assignments  permitted  hereunder  (including
                  the assignment of any Advance or portion  thereof) may be made
                  with all  voting  rights,  and  shall be made  pursuant  to an
                  Assignment and Assumption Agreement  substantially in the form
                  of Exhibit O attached hereto. An administrative  fee of $3,500
                  shall be payable to the Administrative  Agent by the assigning
                  Bank at the time of any assignment under this Section 11.5(c);

                           (iv) No  participation  agreement  shall  confer  any
                  rights under this  Agreement or any other Loan Document to any
                  purchaser thereof, or relieve any issuing Bank from any of its
                  obligations  under this Agreement,  and all actions  hereunder
                  shall  be  conducted  as if no  such  participation  had  been
                  granted;  provided,  however, that any participation agreement
                  may  confer  on  the  participant  the  right  to  approve  or
                  disapprove  decreases in the interest  rate,  increases in the
                  principal  amount  of  the  Loans   participated  in  by  such
                  participant,  decreases  in fees,  extensions  of the 

                                       -76-
<PAGE>


                  Maturity Date or other principal payment date for the Loans or
                  of the scheduled  reduction of the  Commitment and releases of
                  Collateral;

                           (v) Each Bank  agrees to provide  the  Administrative
                  Agent  and the  Borrower  with  prompt  written  notice of any
                  issuance of  participations in or assignments of its interests
                  hereunder;

                           (vi) No assignment,  participation  or other transfer
                  of any rights  hereunder  or under the Notes shall be effected
                  that would result in any interest requiring registration under
                  the Securities Act of 1933, as amended, or qualification under
                  any state securities law;

                           (vii) No such  assignment  may be made to any bank or
                  other  financial  institution  (x)  with  respect  to  which a
                  receiver or conservator  (including,  without limitation,  the
                  Federal Deposit  Insurance  Corporation,  the Resolution Trust
                  Company  or  the  Office  of  Thrift   Supervision)  has  been
                  appointed or (y) that is not "adequately capitalized" (as such
                  term is defined in Section 131(b)(1)(B) of the Federal Deposit
                  Insurance  Corporation  Improvement  Act as in  effect  on the
                  Agreement Date); and

                           (viii)  If  applicable,  each Bank  shall,  and shall
                  cause each of its assignees to, provide to the  Administrative
                  Agent on or prior to the effective  date of any  assignment an
                  appropriate  Internal  Revenue  Service  form as  required  by
                  Applicable Law supporting  such Bank's or assignee's  position
                  that no  withholding  by the  Borrower  or the  Administrative
                  Agent for U.S.  income tax payable by such Bank or assignee in
                  respect of amounts  received by it hereunder is required.  For
                  purposes of this Agreement,  an appropriate  Internal  Revenue
                  Service  form shall  mean Form 1001  (Ownership  Exemption  or
                  Reduced Rate Certificate of the U.S.  Department of Treasury),
                  or Form  4224  (Exemption  from  Withholding  of Tax on Income
                  Effectively  Connected with the Conduct of a Trade or Business
                  in the United  States),  or any  successor  or  related  forms
                  adopted by the relevant U.S. taxing authorities.

                   (d) Except as  specifically  set forth in Section  11.5(b) or
(c) hereof,  nothing in this  Agreement or the Notes,  expressed or implied,  is
intended  to or shall  confer on any Person  other than the  respective  parties
hereto and thereto and their  successors and assignees  permitted  hereunder and
thereunder  any benefit or any legal or equitable  right,  remedy or other claim
under this Agreement or the Notes.

                   (e) In the case of any participation,  all amounts payable by
the Borrower under the Loan Documents shall be calculated and made in the manner
and to the parties hereto as if no such participation had been sold.

                                       -77-
<PAGE>


                   (f) The  provisions  of this  Section 11.5 shall not apply to
any purchase of participations among the Banks pursuant to Section 2.11 hereof.

         Section 11.6 Accounting Principles. All references in this Agreement to
GAAP shall be to such  principles as in effect from time to time. All accounting
terms used herein  without  definition  shall be used as defined under GAAP. All
references to the financial statements of the Borrower and to its Operating Cash
Flow,  Total Debt, Fixed Charges,  Pro Forma Debt Service,  and other such terms
shall be  deemed  to refer to such  items  of the  Borrower  and its  Restricted
Subsidiaries,  on a fully consolidated  basis. The Borrower shall deliver to the
Banks at the same time as the  delivery  of any  quarterly  or annual  financial
statements required pursuant to Section 6.1 or 6.2 hereof, as applicable,  (a) a
description  in  reasonable  detail  of  any  material   variation  between  the
application  of GAAP  employed in the  preparation  of such  statements  and the
application of GAAP employed in the preparation of the next preceding  quarterly
or annual financial statements,  as applicable,  and (b) reasonable estimates of
the differences  between such statements arising as a consequence  thereof.  If,
within thirty (30) days after the delivery of the quarterly or annual  financial
statements referred to in the immediately preceding sentence, the Majority Banks
shall object in writing to the Borrower's  determining  compliance  hereunder on
such  basis,  (1)  calculations  for  the  purposes  of  determining  compliance
hereunder shall be made on a basis consistent with those used in the preparation
of the latest  financial  statements as to which such  objection  shall not have
been  made,  or (2) if  requested  by the  Borrower,  the  Majority  Banks  will
negotiate  in good  faith to amend the  covenants  herein to give  effect to the
changes in GAAP in a manner  consistent  with this Agreement (and so long as the
Borrower  complies in good faith with the  provisions  of this Section  11.6, no
Default or Event of Default  shall  occur  hereunder  solely as a result of such
changes in GAAP).

         Section 11.7 Counterparts. This Agreement may be executed in any number
of counterparts,  each of which shall be deemed to be an original,  but all such
separate counterparts shall together constitute but one and the same instrument.

         Section  11.8  Governing  Law.  This  Agreement  and the Notes shall be
construed in  accordance  with and governed by the internal laws of the State of
New York  applicable to agreements  made and to be performed in New York. If any
action or proceeding  shall be brought by the  Administrative  Agent or any Bank
hereunder  or under any other Loan  Document  in order to  enforce  any right or
remedy under this  Agreement or under any Note or any other Loan  Document,  the
Borrower  hereby  consents and will, and the Borrower will cause each Restricted
Subsidiary  to,  submit to the  jurisdiction  of any state or  federal  court of
competent  jurisdiction sitting within the area comprising the Southern District
of New York on the date of this  Agreement.  The  Borrower,  for  itself  and on
behalf  of its  Restricted  Subsidiaries,  hereby  agrees  that,  to the  extent
permitted by Applicable Law,  service of the summons and complaint and all other
process  which may be  served in any such  suit,  action  or  proceeding  may be
effected by mailing by registered  mail a copy of such process to the 

                                       -78-
<PAGE>

offices of the  Borrower  at the address  given in Section  11.1 hereof and that
personal  service of process  shall not be  required.  Nothing  herein  shall be
construed to prohibit  service of process by any other method  permitted by law,
or the bringing of any suit, action or proceeding in any other jurisdiction. The
Borrower agrees that final judgment in such suit,  action or proceeding shall be
conclusive and may be enforced in any other jurisdiction by suit on the judgment
or in any other manner provided by Applicable Law.

         Section 11.9  Severability.  Any provision of this  Agreement  which is
prohibited or  unenforceable  in any  jurisdiction  shall be  ineffective to the
extent  of  such  prohibition  or  unenforceability   without  invalidating  the
remaining  provisions  hereof in that  jurisdiction or affecting the validity or
enforceability of such provision in any other jurisdiction.               

         Section 11.10 Interest.

                  (a) In no event  shall the amount of  interest  due or payable
hereunder  or under the Notes  exceed the maximum  rate of  interest  allowed by
Applicable Law, and in the event any such payment is  inadvertently  made by the
Borrower or inadvertently received by the Administrative Agent or any Bank, then
such excess sum shall be credited as a payment of principal, unless the Borrower
shall notify the Administrative  Agent or such Bank, in writing,  that it elects
to have such excess sum returned forthwith. It is the express intent hereof that
the  Borrower  not pay and the  Administrative  Agent and the Banks not receive,
directly  or  indirectly  in any manner  whatsoever,  interest in excess of that
which may legally be paid by the Borrower under Applicable Law.

                   (b) Notwithstanding the use by the Banks of the Base Rate and
the LIBOR as reference rates for the determination of interest on the Loans, the
Banks shall be under no obligation to obtain funds from any particular source in
order to charge  interest  to the  Borrower at  interest  rates  related to such
reference rates.

         Section 11.11 Table of Contents and Headings. The Table of Contents and
the  headings  of the  various  subdivisions  used  in  this  Agreement  are for
convenience  only and shall  not in any way  modify or amend any of the terms or
provisions  hereof,  nor be used in connection  with the  interpretation  of any
provision hereof.
                                   

         Section 11.12 Amendment and Waiver. Neither this Agreement nor any Loan
Document  nor any term  hereof or  thereof  may be amended  orally,  nor may any
provision  hereof or  thereof  be waived  orally  but only by an  instrument  in
writing  signed by or at the direction of the Majority Banks and, in the case of
an amendment,  by the Borrower,  except that in the event of (a) any increase in
the amount of any Bank's portion of the  Commitment,  (b) any delay or extension
in the terms of  repayment  of the Loans  provided in Section 2.5 or 2.7 hereof,
(c) any reduction in principal,  interest or fees due hereunder or  postponement
of the  payment  thereof  without a  corresponding  payment  of such  principal,
interest  or fee 

                                       -79-
<PAGE>

amount by the Borrower, (d) any release of any portion of the Collateral for the
Loans, except under Section 7.4 hereof, (e) any waiver of any Default due to the
failure by the  Borrower to pay any sum due to any of the Banks  hereunder,  (f)
any release of any Guaranty of all or any portion of the Obligations,  except in
connection  with  a  merger,  sale  or  other  disposition  otherwise  permitted
hereunder (in which case, such release shall require no further  approval by the
Banks),  (g) any  amendment to the pro rata  treatment of the Banks set forth in
Section  2.11  hereof,  or (h) any  amendment  of  this  Section  11.12,  of the
definition of Majority  Banks,  or of any Section herein to the extent that such
Section  requires action by all Banks, any amendment or waiver or consent may be
made only by an  instrument  in writing  signed by each of the Banks and, in the
case of an amendment,  by the Borrower. Any amendment to any provision hereunder
governing the rights, obligations, or liabilities of the Administrative Agent in
its capacity as such,  may be made only by an  instrument  in writing  signed by
such affected Person and by each of the Banks.

         Section 11.13 Entire Agreement.  Except as otherwise expressly provided
herein,  this Agreement and the other documents described or contemplated herein
will embody the entire agreement and understanding  among the parties hereto and
thereto and supersede all prior  agreements and  understandings  relating to the
subject matter hereof and thereof.                                    

         Section 11.14 Other Relationships. No relationship created hereunder or
under any  other  Loan  Document  shall in any way  affect  the  ability  of the
Administrative   Agent  and  each  Bank  to  enter  into  or  maintain  business
relationships   with  the  Borrower  or  any  of  its   Affiliates   beyond  the
relationships  specifically  contemplated  by this  Agreement and the other Loan
Documents.                                    

         Section  11.15  Directly  or  Indirectly.  If  any  provision  in  this
Agreement refers to any action taken or to be taken by any Person, or which such
Person is prohibited  from taking,  such provision  shall be applicable  whether
such  action is taken  directly or  indirectly  by such  Person,  whether or not
expressly specified in such provision.                                    

         Section  11.16  Reliance  on and  Survival of Various  Provisions.  All
covenants, agreements, statements, representations and warranties made herein or
in any  certificate  delivered  pursuant hereto (a) shall be deemed to have been
relied upon by the  Administrative  Agent and each of the Banks  notwithstanding
any  investigation  heretofore or hereafter  made by them, and (b) shall survive
the  execution  and  delivery of the Notes and shall  continue in full force and
effect  so  long  as  any  Note  is  outstanding   and  unpaid.   Any  right  to
indemnification  hereunder,  including,  without limitation,  rights pursuant to
Sections 2.10, 2.12,  5.12, 10.3 and 11.2 hereof,  shall survive the termination
of this Agreement and the payment and performance of all Obligations.

                                       -80-
<PAGE>


         Section 11.17 Senior Debt. The  Obligations are secured by the Security
Documents  and are  intended  by the  parties  hereto to be in  parity  with the
Interest  Hedge  Agreements  and  senior  in  right  of  payment  to  all  other
Indebtedness of the Borrower.                                    

         Section 11.18 Obligations.  The obligations of the Administrative Agent
and each of the Banks hereunder are several, not joint.                  

         Section  11.19  Confidentiality.  The Banks shall hold all  non-public,
proprietary or  confidential  information  (which has been identified as such by
the  Borrower)  obtained  pursuant  to the  requirements  of this  Agreement  in
accordance with their customary procedures for handling confidential information
of this  nature  and in  accordance  with  safe  and  sound  banking  practices;
provided,  however,  the Banks may make  disclosure of any such  information  to
their examiners, Affiliates, outside auditors, counsel, consultants,  appraisers
and  other  professional  advisors  in  connection  with  this  Agreement  or as
reasonably  required by any proposed syndicate member or any proposed transferee
or  participant  in  connection  with the  contemplated  transfer of any Note or
participation therein or as required or requested by any governmental  authority
or representative thereof or in connection with the enforcement hereof or of any
Loan  Document or related  document or pursuant to legal process or with respect
to any litigation between or among the Borrower and any of the Banks, so long as
the person (other than any examiners)  receiving such  information is advised of
the provisions of this Section 11.19 and agrees to be bound thereby. In no event
shall any Bank be obligated or required to return any materials  furnished to it
by the Borrower. The foregoing provisions shall not apply to a Bank with respect
to information that (i) is or becomes  generally  available to the public (other
than through  such Bank),  (ii) is already in the  possession  of such Bank on a
nonconfidential  basis,  or (iii)  comes into the  possession  of such Bank in a
manner not known to such Bank to  involve a breach of a duty of  confidentiality
owing to the Borrower.


                        ARTICLE 12 Waiver of Jury Trial

         Section  12.1 Waiver of Jury  Trial.  THE  BORROWER,  FOR ITSELF AND ON
BEHALF OF ITS  RESTRICTED  SUBSIDIARIES,  AND THE  ADMINISTRATIVE  AGENT AND THE
BANKS,  HEREBY AGREE, TO THE EXTENT  PERMITTED BY LAW, TO WAIVE AND HEREBY WAIVE
THE RIGHT TO A TRIAL BY JURY IN ANY COURT AND IN ANY ACTION OR PROCEEDING OF ANY
TYPE IN WHICH THE BORROWER, ANY OF THE BORROWER'S RESTRICTED  SUBSIDIARIES,  ANY
OF THE BANKS, THE ADMINISTRATIVE AGENT OR ANY OF THEIR RESPECTIVE  SUCCESSORS OR
ASSIGNS IS A PARTY, AS TO ALL MATTERS AND THINGS ARISING  DIRECTLY OR INDIRECTLY
OUT OF THIS  AGREEMENT,  ANY OF THE NOTES OR THE OTHER  LOAN  DOCUMENTS  AND THE
RELATIONS AMONG THE PARTIES LISTED IN THIS SECTION 12.1. EXCEPT AS PROHIBITED BY
LAW,  EACH  

                                       -81-
<PAGE>


PARTY TO THIS AGREEMENT WAIVES ANY RIGHTS IT MAY HAVE TO CLAIM OR RECOVER IN ANY
LITIGATION  REFERRED TO IN THIS  SECTION,  ANY SPECIAL,  EXEMPLARY,  PUNITIVE OR
CONSEQUENTIAL  DAMAGES OR ANY DAMAGES  OTHER THAN,  OR IN  ADDITION  TO,  ACTUAL
DAMAGES.   EACH  PARTY  TO  THIS   AGREEMENT  (A)  CERTIFIES  THAT  NEITHER  ANY
REPRESENTATIVE,  AGENT OR ATTORNEY OF THE  ADMINISTRATIVE  AGENT OR ANY BANK HAS
REPRESENTED,  EXPRESSLY OR OTHERWISE,  THAT THE ADMINISTRATIVE AGENT OR ANY BANK
WOULD NOT, IN THE EVENT OF LITIGATION, SEEK TO ENFORCE THE FOREGOING WAIVERS AND
(B) ACKNOWLEDGES  THAT IT HAS BEEN INDUCED TO ENTER INTO THIS AGREEMENT AND EACH
OTHER  LOAN   DOCUMENT  BY,  AMONG  OTHER   THINGS,   THE  MUTUAL   WAIVERS  AND
CERTIFICATIONS  IN THIS SECTION.  THE PROVISIONS OF THIS SECTION HAVE BEEN FULLY
DISCLOSED  BY AND TO THE  PARTIES  AND THE  PROVISIONS  SHALL BE  SUBJECT  TO NO
EXCEPTIONS.  NO PARTY HAS IN ANY WAY  AGREED  WITH OR  REPRESENTED  TO ANY OTHER
PARTY THAT THE  PROVISIONS  OF THIS  SECTION  WILL NOT BE FULLY  ENFORCED IN ALL
INSTANCES.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]




<PAGE>




         IN WITNESS WHEREOF,  the parties hereto have executed this Agreement or
caused it to be executed by their duly  authorized  officers,  all as of the day
and year first above written.


BORROWER:                                 AMERICAN TOWER SYSTEMS, INC., a 
                                          Delaware corporation


                                          By: /s/ Joseph J. Winn
                                              Its: Chief Financial Officer


ADMINISTRATIVE AGENT:                     TORONTO DOMINION (TEXAS), INC., as
                                          Administrative Agent


                                          By: /s/ Kimberly Burleson
                                              Its: Vice President


BANKS:                                    TORONTO DOMINION (TEXAS), INC., as a
                                          Bank

Address:
909 Fannin Street, Suite 1700             By:/s/ Kimberly Burleson   
Houston, Texas  77010                        Its: Vice President     
Telecopy: (713) 951-9921                           


                                          BANQUE PARIBAS, as a Bank

Address:
The Equitable Tower                       By:
787 Seventh Avenue
New York New York  10022                      Its: Vice President
Telecopy: (212) 841-2369

                                          By: /s/ Lynne S. Randall
                                              Its: Director

                                       
<PAGE>



                                          BARCLAYS BANK PLC, as a Bank

Address:
75 Wall Street, 12th Floor                By:
New York, New York  10015
Telecopy: (212) 412-5308                     Its:  Associate Director


                                          BANK OF MONTREAL, CHICAGO BRANCH, 
                                          as a Bank

Address:
430 Park Avenue, 15th Floor               By: /s/ W.T. Calder
New York, New York  10022                     Its: Director
Telecopy: (212) 605-1648                           


                                          THE CHASE MANHATTAN BANK, as a Bank

Address:
270 Park Avenue, 37th Floor               By: /s/ Mitchell J. Gervis
New York, New York  10017                     Its: Vice President
Telecopy: (212) 270-4584                           


                                          FLEET NATIONAL BANK, as a Bank

Address:
MA/OF/DO3D                                By: 
One Federal Street                            Its: Vice President
Boston, Massachusetts  02110                      
Telecopy: (617) 346-4356


                                          GE CAPITAL CORPORATION, as a Bank

Address:
120 Longridge Road, 3rd Floor             By: /s/ Molly S. Fergurson
Stamford, Connecticut  06927                  Its: Manager, Operations
Telecopy: (203) 357-6828                           


<PAGE>


                                          THE BANK OF NEW YORK, as a Bank

Address:
One Wall Street, 16th Floor               By: 
New York, New York  10286                     Its: Vice President
Telecopy: (212) 635-8593                          


                                          CREDIT SUISSE FIRST BOSTON, as a Bank

Address:
11 Madison Avenue, 20th Floor             By: /s/ Todd C. Morgan
New York, New York  10010                     Its: Vice President
Telecopy: (212) 325-8314                           

                                          By: /s/ Judit E. Smith
                                              Its: Director


                                          SUNTRUST BANK, CENTRAL FLORIDA, 
                                          NATIONAL ASSOCIATION, as a Bank

Address:
200 S. Orange Avenue                      By: 
Orlando, Florida  32801                       Its: Vice President
Telecopy: (407) 237-4253                         


                                          UNIOBANK OF CALIFORNIA, N.A., 
                                          as a Bank

Address:
445 S. Figueroa, 15th Floor               By: /s/ Peter C. Connoy
Los Angeles, California  90071                Its: Assistant Vice President
Telecopy: (213) 236-5747                           
<PAGE>


                                          THE BANK OF NOVA SCOTIA, as a Bank

Address:
One Liberty Plaza                         By: /s/ Margot C. Bright
New York, New York  10006                     Its: Authorized Signatory
Telecopy: (212) 225-5090                          


                                          CREDIT LYONNAIS NEW YORK BRANCH, 
                                          as a Bank

Address:
1301 Avenue of the Americas               By: /s/ Stephen C. Levi
18th Floor                                    Its: Vice President
New York, New York  10019                          
Telecopy: (212) 261-3288


                                          THE SUMITOMO BANK, LIMITED, acting 
                                          through its Chicago Branch, as a Bank

Address:
1 Post Office Square, Suite 3820          By: 
Boston, Massachusetts  02109                  Its: Vice President & Manager
Telecopy: (617) 423-4884                  
     and
Lending Office Address:
233 South Wacker, Suite 5400              By: /s/ Jean Robert
Chicago, Illinois  60606                      Its: Executive Officer


                                          BANK OF SCOTLAND, as a Bank

Address:
565 Fifth Avenue                          By: /s/ Annie Chin Tat
New York, New York  10017                     Its: Vice President
Telecopy: (212) 557-9460                        
<PAGE>


                                         LEHMAN COMMERCIAL PAPER INC., as a Bank

Address:
3 World Financial Center, 10th Floor     By: /s/ Dennis J. Lee
New York, New York  10285                    Its: Authorized Signatory
Telecopy: (212) 528-0819