Document:

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                                                                    Exhibit 10.1

                         EXECUTIVE EMPLOYMENT AGREEMENT

     THIS EXECUTIVE EMPLOYMENT AGREEMENT (the "Agreement"), made as of the 25th
day of July, 2002, is entered into by Pegasystems Inc., a Massachusetts
corporation with its principal place of business at 101 Main Street, Cambridge,
Massachusetts 02142 (the "Company"), and Henry Ancona, residing at 180 Beacon
Street, Boston, Massachusetts 02116 (the "Executive").

     The Company desires to employ the Executive, and the Executive desires to
be employed by the Company. In consideration of the mutual covenants and
promises contained herein, and other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged by the parties hereto,
the parties agree as follows:

     1. Term of Employment. The Company hereby agrees to employ the Executive,
and the Executive hereby accepts employment with the Company, upon the terms set
forth in this Agreement, for the period (the "Employment Period") commencing on
July 25, 2002 (the "Commencement Date") and ending when terminated in accordance
with the provisions of Section 4.

     2. Title; Capacity. (a) The Executive shall serve as President and Chief
Operating Officer of the Company, subject to the general direction and control
of the Company's Board of Directors (the "Board") and its Chief Executive
Officer (the "CEO"). The Company will use its best efforts to cause the
Executive to be elected to the Board prior to December 31, 2002. The Executive
hereby accepts such employment and agrees to undertake the duties and
responsibilities inherent in such position and such other executive duties and
responsibilities as the Board or the CEO shall from time to time reasonably
assign to him.

          (b) All employees of the Company other than the CEO and his
administrative assistant shall report to the Executive.

          (c) The Executive agrees to devote his entire business time, attention
and energies to the business and interests of the Company during the Employment
Period provided, however, that Executive shall be allowed, to the extent that
such activities do not materially interfere with the performance of his duties
and responsibilities hereunder, to manage his personal and family financial and
legal affairs and to serve on corporate, civic, not-for-profit, charitable and
industry boards and advisory committees. Notwithstanding the foregoing, the
Executive shall only serve on for-profit corporate boards of directors and
advisory committees if approved in advance by the Board or the CEO.

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     3. Compensation and Benefits.

          3.1 Salary. The Company shall pay the Executive an annual base salary
of $325,000 during the Employment Period. Such base salary shall be subject to
review by the Compensation Committee of the Board and, based on such review, may
be changed by the Compensation Committee in its sole discretion.

          3.2 Bonuses. The Company shall pay the Executive an annual cash bonus
targeted at 50% of his annual base salary, with the actual bonus amount being
dependent on the achievement of goals and objectives. Each such bonus shall be
paid within 90 days after the end of the calendar year to which it relates, and,
except as provided in Section 5 shall be conditioned upon the Executive's
employment by the Company through the end of the calendar year to which it
relates.

          3.3 Fringe Benefits. The Executive shall be entitled to participate in
all bonus and benefit programs (collectively, "Benefits") that the Company
establishes and makes available to its senior executive employees, to the extent
that the Executive's position, tenure, salary, age, health and other
qualifications make him eligible to participate.

          3.4 Vacation. The Executive shall be entitled to four (4) weeks paid
vacation per year.

          3.5 Reimbursement of Expenses. The Company shall reimburse the
Executive for all reasonable travel, entertainment and other expenses incurred
or paid by the Executive in connection with, or related to, the performance of
his duties, responsibilities or services under this Agreement, subject to the
Executive's compliance with the Company's standard expense reimbursement
policies.

          3.6 Stock Options. (a) On the Commencement Date, the Company will
grant the Executive a nonqualified 10-year option under the Company's 1994
Long-Term, Incentive Plan (the "Plan") to purchase 500,000 shares of the
Company's common stock, $.01 par value per share ("Common Stock"), at a price
equal to the fair market value of the Common Stock on such date as determined in
accordance with the Plan. Such option shall vest in equal quarterly installments
over four (4) years.

          (b) In the event of a termination of the Executive's employment by the
Company without Cause, by the Executive for Good Reason or as a result of the
Executive's death (as each term is defined below), all vested stock options then
held by the Executive shall remain exercisable for at least one (1) year after
such termination, but in no event beyond the original term of the stock option.
In the event of a termination of the Executive's employment as a result of
Disability or "retirement" (as defined in the Plan), all vested stock options
then held by the Executive shall remain exercisable for at least two (2) years
after such termination, but in no event beyond the original term of the stock
option. Upon any other termination, all vested stock options held by the
Executive shall remain exercisable for at least 90 days after such termination,
but in no event beyond the original term of the stock option.

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     4. Employment Termination. The employment of the Executive by the Company
pursuant to this Agreement shall terminate upon the occurrence of any of the
following:

          4.1 At the election of the Company, for Cause, immediately upon
written notice by the Company to the Executive given within 90 days after the
Cause event becomes known to the Company. For the purposes of this Agreement,
Cause shall mean: (A) a material breach by the Executive of this Agreement or a
material breach by the Executive of the Company's Code of Conduct, in each case
that is not cured within 10 days following receipt by the Executive of written
notice from the Company specifying the details thereof, (B) Executive's willful
failure to attempt in good faith to follow the legal written direction of the
Board or the CEO, which is not cured within 10 days following receipt by the
Executive of written notice from the Board or the CEO specifying the details
thereof, (C) Executive's conviction of a felony (other than a felony involving a
traffic violation or as a result of vicarious liability), (D) Executive's
commission of an act constituting fraud, embezzlement, larceny or theft with
regard to the Company that is of a material nature (other than good faith
expense account reimbursement disputes) or (E) willful misconduct by the
Executive with regard to the Company that has a material adverse effect on the
Company. For purposes of this paragraph, no act, or failure to act, on
Executive's part shall be considered "willful" unless done or omitted to be
done, by him not in good faith and without reasonable belief that his action or
omission was in the best interests of the Company. For purposes of clause (A)
above, the Company's "Code of Conduct" shall mean such code as currently in
effect and as it may hereafter be amended from time to time, provided that any
such amendment is communicated to the Executive in writing or electronically.

          4.2 Upon the death of the Executive, or upon 30 days' written notice
from the Company after the Executive has incurred a Disability and remains
disabled, unless he returns to the full-time performance of his duties within
such 30-day period. As used in this Agreement, the term Disability shall mean
the failure of the Executive, due to a physical or mental disability, to perform
the services contemplated by this Agreement for a period of 120 days, whether or
not consecutive, during any 360-day period.

          4.3 At the election of the Company, without cause, immediately upon
written notice by the Company to the Executive.

          4.4 At the election of the Executive for Good Reason, provided that
the Executive shall have given written notice to the Board within 90 days after
he becomes aware of the occurrence of any event of Good Reason specifying such
event, and such event shall be continued for a period of ten (10) days following
such notice. For purposes of this Agreement, Good Reason means any of the
following events (unless consented to by the Executive in writing): (i) a
material diminution in the Executive's duties, responsibilities or authorities
or the assignment to the Executive of duties or responsibilities that are
materially adversely consistent with his then position; (ii) any individual
appointed as the CEO other than the current CEO or the Executive; (iii) any
material breach by the Company of this Agreement; (iv) failure of the Executive
to be elected to the Board by September 1, 2003, or the Executive's removal
from, or failure to be re-elected to the Board once elected thereto; (v) a
reduction in the Executive's base salary or targeted bonus; (vi) a requirement
by the Company that the Executive's principal place

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of work to be moved to a location more than 35 miles away from Cambridge,
Massachusetts; (vii) a requirement by the Company that the Executive report to a
person other than the CEO; or (viii) a change in the Executive's title to a
lesser title.

          4.5 At the election of the Executive, without Good Reason, upon at
least 60 days' prior written notice to the Company.

     5. Effect of Termination.

          5.1 Termination Pursuant to Section 4.2. In the event the Executive's
employment is terminated by reason of the Executive's death or Disability, the
Company shall pay or provide to the Executive (or his estate in the case of a
termination due to the Executive's death) any compensation and Benefits accrued
and otherwise payable to him under Section 3 through the last day of his actual
employment by the Company (including, without limitation, any bonus if declared
or earned but not yet paid for a completed fiscal year), and accrued vacation
pay payable pursuant to the Company's policies, and any unreimbursed business
expenses payable pursuant to Company policy (collectively the "Accrued
Amounts"), which amounts shall promptly be paid in a lump sum. In addition, the
Company shall: (i) continue to provide him and his dependents, for the
twelve-month period commencing on the date of such termination, with the
Benefits to which he would otherwise have been entitled hereunder had his
employment not been terminated and (ii) pay to the Executive (or his estate in
the case of his death) a pro-rata bonus for the year of termination equal to,
the product of (x) the target annual bonus for the fiscal year of Executive's
termination, multiplied by (y) a fraction, the numerator of which is the number
of days of the current fiscal year during which Executive was employed by the
Company, and the denominator of which is 365, which bonus shall be paid when
bonuses for such period are paid to the other executives (the "Pro-Rata Bonus").

          5.2 Termination Pursuant to Sections 4.3 or 4.4. In the event the
Executive's employment is terminated by the Company without cause or, by the
Executive for Good Reason, the Company shall pay or provide the Executive with
the following:

     (A) within thirty (30) days after the date of such termination, pay him a
lump sum amount equal to his then current annual base salary;

     (B) continue to provide him, for the twelve-month period commencing on the
date of such termination, with the Benefits to which he would otherwise have
been entitled hereunder had his employment not been terminated; and

     (C) If the termination occurs at least twelve (12) months after the
Commencement Date, then the Company will accelerate in full the vesting of the
Executive's options to purchase shares of the Company's Common Stock so that
such options are immediately exercisable; and

     (D) the Executive shall receive the Pro-Rata Bonus.

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          5.3 Termination Pursuant to Sections 4.1 or 4.5. If the Executive's
employment is terminated by the Company for Cause or by the Executive without
Good Reason, the Company shall pay to the Executive the Accrued Amounts.

     6. Standards Letter. Concurrently with the execution and delivery of this
Agreement, the Executive agrees to execute and deliver the Company's "standards
letter" in the form most recently signed by an executive officer of the Company
except that such letter shall be modified to provide that if the Executive's
employment hereunder is terminated prior to the first anniversary of the
Commencement Date by the Company without Cause or by the Executive for Good
Reason then the non-competition covenants contained in such letter shall have no
force or effect. The provisions of the standards letter executed by the
Executive (the "Standards Letter") shall survive the termination of this
Agreement.

     7. Release. It will be a condition for receipt of the benefits described in
Section 5 above (other than the Accrued Amounts) that the Executive: (i) return
Company property, (ii) execute a general release (in the form attached hereto)
regarding his employment and (iii) materially comply with the provisions of the
Standards Letter.

     8. Other Agreements. The Executive hereby represents and warrants that he
is not bound by the terms of any agreement to refrain from competing, directly
or indirectly, with the business of such previous employer or any other party.
The Executive further represents and warrants that his performance of all the
terms of this Agreement does not and will not breach any other agreement to
which the Executive is a party or otherwise bound; provided that there are
certain limitations with regard to confidentiality from prior employers.

     9. No Mitigation; No Set-Off. In the event of any termination of employment
hereunder, Executive shall be under no obligation to seek other employment and
there shall be no offset against any amounts due Executive under this Agreement
on account of any remuneration attributable to any subsequent employment that
Executive may obtain. The Company's obligation to pay Executive the amounts
provided and to make the arrangement provided hereunder shall not be subject to
set-off, counterclaim or recoupment except for any amounts the Executive owes to
the Company under any promissory note.

     10. Indemnification. The Company shall indemnify and hold harmless
Executive to the fullest extent permitted by law (including the advancement of
legal fees) for any action or inaction of Executive while serving as an officer
or director of the Company or, at the Company's request, as an officer or
director of any other entity or as a fiduciary of any benefit plan, except for
any activity by the Executive that constitutes gross negligence or is
self-enriching. The Company shall cover the Executive under directors and
officers liability insurance both during and, while potential liability exists,
after the Employment Period in the same amount and to the same extent as the
Company covers its other officers and directors.

     11. Arbitration. All disputes and controversies arising under or in
connection with this Agreement, other than the seeking of injunctive or other
equitable relief pursuant to the Standards Letter, shall be settled by
arbitration conducted before one arbitrator sitting in Boston, Massachusetts, or
such other location agreed by the parties hereto, in accordance with the

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National Rules for the Resolution of Employment Disputes of the American
Arbitration Association then in effect. The determination of the arbitrator
shall be final and binding on the parties. Judgment may be entered on the award
of the arbitrator in any court having proper jurisdiction.

     12. Notices. All notices required or permitted under this Agreement shall
be in writing and shall be deemed effective upon personal delivery or upon
deposit in the United States Post Office, by registered or certified mail,
postage prepaid, addressed to the other party at the address shown above, or at
such other address or addresses as either party shall designate to the other in
accordance with this Section 12.

     13. Entire Agreement. This Agreement constitutes the entire agreement
between the parties and supersedes all prior agreements and understandings,
whether written or oral, relating to the subject matter of this Agreement.

     14. Amendment. This Agreement may be amended or modified only by a written
instrument executed by both the Company and the Executive.

     15. Governing Law. This Agreement shall be construed, interpreted and
enforced in accordance with the laws of The Commonwealth of Massachusetts.

     16. Successors and Assigns. This Agreement shall be binding upon and inure
to the benefit of both parties and their respective successors and assigns,
provided that the Company may assign the Agreement only to an acquiror of all or
substantially all of its assets and business, and further provided, however,
that the obligations of the Executive are personal and shall not be assigned by
him. Any successor to the Company shall assume the obligations under this
Agreement in a writing delivered to the Executive upon the assignee becoming
such.

     17. Miscellaneous.

          17.1 No delay or omission by the Company in exercising any right under
this Agreement shall operate as a waiver of that or any other right. A waiver or
consent given by the Company on any one occasion shall be effective only in that
instance and shall not be construed as a bar or waiver of any right on any other
occasion.

          17.2 The captions of the sections of this Agreement are for
convenience of reference only and in no way define, limit or affect the scope or
substance of any section of this Agreement.

          17.3 In case any provision of this Agreement shall be invalid, illegal
or otherwise unenforceable, the validity, legality and enforceability of the
remaining provisions shall in no way be affected or impaired thereby.

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         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the day and year set forth above.

                                                  PEGASYSTEMS INC.

                                                  By: /s/ Alan Trefler
                                                      --------------------------
                                                  Title: Chief Executive Officer

                                                      /s/ Henry Ancona
                                                      --------------------------

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<PAGE>

                         CONFIDENTIAL RELEASE OF CLAIMS

     I, Henry Ancona, in consideration of certain separation payments that
Pegasystems Inc. (the "Company") is agreeing to make to me upon the
effectiveness of this Release, agree with the Company as follows:

     1. General Release. On behalf of myself and my spouse, heirs, executors,
        ---------------
administrators, trustees, legal representatives, and assigns, I hereby forever
release and discharge the Company, its predecessors and successors, and each of
its past and present parent corporations, divisions, subsidiaries, affiliates,
assigns, officers, directors, employees, consultants, shareholders, partners,
attorneys, and agents (any or all of which are referred to as the "Releasees")
from any and all claims, demands, liabilities, actions, and causes of action of
every name and nature, whether known or unknown, with regard to my employment
with the Company and termination therefrom which could have been asserted from
the beginning of the world to the date on which I sign this Release. This
release includes, but is not limited to, (a) any claims for breach of contract,
whether express or implied; (b) any claims for wrongful termination; (c) any
claims for reemployment, salary, wages, bonuses, vacation pay, benefits, or
other compensation of any kind; (d) any claims for harassment, discrimination,
or retaliation in employment, including but not limited to any claims under
Title VII of the Civil Rights of 1964, the Age Discrimination in Employment Act,
Massachusetts General Laws Chapter 151B, the Employee Retirement Income Security
Act, the Americans with Disabilities Act, the Family and Medical Leave Act, and
any other federal, state, or local statute, ordinance, regulation, or common law
relating to harassment, discrimination, or retaliation in employment; (e) any
claims under any other federal, state, or local statutes, ordinances, or
regulations; (f) any claims based in tort; (g) any other common-law claims; and
(h) any claims for costs or attorneys' fees. Nothing herein shall release the
Releasees from any claims based on: (i) my right to enforce this Release or the
provisions of my employment agreement with the Company, (ii) any right I may
have to vested or accrued benefits, (iii) any right to indemnification or
(iv) any rights as a shareholder.

     2. Company Property. I agree and acknowledge that I have returned to the
        ----------------
Company all originals and copies of Company documents and all other Company
property that was in my possession at the time of my termination of employment,
including without limitation, all keys, corporate credit cards, computer files,
diskettes, database information, client information, sales documents, financial
statements, budgets and forecasts, and any similar information. Notwithstanding
the foregoing, I am permitted to retain my rolodex and similar address and
telephone directories.

     3. Non-Disparagement. I agree not to intentionally make any public
        -----------------
statement, written or oral, which disparages the Company, its services, or any
of its directors, officers, employees, or agents. The Company shall cause its
senior executive officers not to intentionally make any public statement,
written or oral, which disparages me.

     4. Confidentiality. I agree to keep the terms of this Release and the
        ---------------
amount of separation payments paid to me in exchange for signing this Release
completely confidential, and not to disclose any such matters to anyone, in
words or in substance, except as set forth in

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<PAGE>

this section. Notwithstanding the foregoing, I may disclose such information
(a) to my immediate family, attorney, and/or accountant, provided that I shall
first obtain any such person's agreement to keep any such matters completely
confidential and not to disclose any such matters to anyone; and (b) to the
extent required by law or if compelled pursuant to the order of a court or
governmental body or agency.

     5. Notice and Right to Consider. I have been advised to consult with an
        ----------------------------
attorney before signing this Release. I acknowledge that I have been given the
opportunity to consider this Release for 21 days before signing it. In the event
that I have signed this Release within less than 21 days, I acknowledge that my
decision was entirely voluntary and that I had the opportunity to consider this
Release for the entire 21-day period. The Company acknowledges that for a period
of seven days from the date on which I sign this Release, I will retain the
right to revoke this Release by written notice that the Company receives before
the end of that seven-day period, and that this Release will not become
effective or enforceable until the expiration of such revocation period.

     6. Miscellaneous. This Release is binding upon me and upon my heirs,
        -------------
administrators, representatives, executors, successors, and assigns. I agree
that I have carefully read and understand all of the provisions of this Release
and that I am voluntarily signing this Release.

-------------------------------     -----------------------------
Henry Ancona                        Date

                                       9<PAGE>

                                                                   EXHIBIT 10.1

                                                                  EXECUTION COPY

                              SEVENTH AMENDMENT TO
                       AMENDED AND RESTATED LOAN AGREEMENT

         THIS SEVENTH AMENDMENT TO AMENDED AND RESTATED LOAN AGREEMENT, dated as
of the 18th day of October, 2002 (this "Amendment"), is made by and among
AMERICAN TOWER CORPORATION, a Delaware corporation (the "Parent"), AMERICAN
TOWER, L.P., a Delaware limited partnership ("AT LP"), AMERICAN TOWERS, INC., a
Delaware corporation ("AT Inc."), TOWERSITES MONITORING, INC., a Delaware
corporation ("Towersites") and AMERICAN TOWER INTERNATIONAL, INC., a Delaware
corporation (collectively, with AT LP, AT Inc. and Towersites, the "Borrowers"),
VERESTAR, INC., a Delaware corporation ("Verestar"), THE FINANCIAL INSTITUTIONS
SIGNATORIES HERETO and TORONTO DOMINION (TEXAS), INC., as administrative agent
(in such capacity, the "Administrative Agent").

                              W I T N E S S E T H:

         WHEREAS, the Borrowers, Verestar, the Lenders (as defined therein), the
Issuing Bank (as defined therein) and the Administrative Agent are all parties
to that certain Amended and Restated Loan Agreement dated as of January 6, 2000
(as previously amended and as hereafter amended, modified, restated and
supplemented from time to time, the "Loan Agreement"); and

         WHEREAS, the Borrowers have requested amendments to certain provisions
of the Loan Agreement, and, subject to the terms and conditions set forth
herein, the Lenders are willing to amend certain provisions of the Loan
Agreement as more specifically set forth herein;

         NOW, THEREFORE, in consideration of the premises set forth above, and
other good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, the parties hereto hereby agree that all capitalized terms
used and not defined herein shall have the meanings ascribed to such terms in
the Loan Agreement, and further hereby agree as follows:

         1. Amendments. The Loan Agreement is hereby amended as more fully set
forth below:

         (a) Amendments to Article 1.

         (i) Section 1.1 of the Loan Agreement, Definitions, is hereby amended
by deleting the definitions of "Borrowers" and "Change of Control" in their
entirety and by substituting the following definitions in lieu thereof:

                  "`Borrowers' shall mean, collectively, AT L.P., AT Inc.,
         Towersites Monitoring, Inc., a Delaware corporation, and ATC
         International, and shall include such other Persons as may be approved
         by the Majority Lenders at such time as any such

<PAGE>

         Person executes and delivers to the Administrative Agent an assignment
         and assumption agreement in form and substance satisfactory to the
         Administrative Agent and also executes and delivers to the
         Administrative Agent every other Loan Document as executed by the other
         Borrowers; and "Borrower" shall mean any one of the foregoing."

                  "`Change of Control' shall mean (a) the failure of the Parent
         to own, directly or indirectly, one hundred percent (100%) of the
         ownership interests of each of the Borrowers, (b) the failure of AT
         Inc. to own, directly or indirectly, one hundred percent (100%) of the
         ownership interests of ATC Operating (unless ATC Operating is merged
         with or into AT Inc.), (c) the sale, lease or transfer, in one or a
         series of related transactions, of all or substantially all of any
         Borrower's assets to any Person or group (as such term is used in
         Section 13(d)(3) of the Exchange Act) other than to the other Borrowers
         or any wholly-owned direct or indirect Restricted Subsidiary of AT
         Inc., (d) the adoption of a plan relating to the liquidation or
         dissolution of the Parent, (e) the acquisition, directly or indirectly,
         by any Person or group (as such term is used in Section 13(d)(3) of the
         Exchange Act) of forty percent (40%) or more of the voting power of the
         voting stock of the Parent by way of merger or consolidation or
         otherwise and such Persons (or group) own more voting power than the
         Principal Shareholders, or (f) the Continuing Directors cease for any
         reason to constitute a majority of the directors of the Parent then in
         office."

         (ii) Section 1.1 of the Loan Agreement, Definitions, is hereby further
amended by deleting each of the definitions of "Incremental Facility
Commitment," Incremental Facility Loans," "Incremental Facility Maturity Date,"
"Incremental Facility Note," and "Notice of Incremental Facility Commitment," in
its entirety; furthermore, each such term is deleted in each place such term is
used in the Loan Agreement.

         (b) Amendments to Article 2.

         (i) Amendment to Section 2.3(f). Sections 2.3(f)(i) and (ii) of the
Loan Agreement, Applicable Margin, is hereby amended by deleting such
subsections in their entirety and substituting in lieu thereof the following:

         "(f) Applicable Margin.

                  (i) Revolving Loans and Term Loan A Loans. With respect to any
         Advance under the Revolving Loan Commitments or the Term Loan A
         Commitments, the Applicable Margin shall be as set forth in a
         certificate of the chief financial officer of a Borrower delivered to
         the Administrative Agent based upon the Leverage Ratio for the most
         recent fiscal quarter end for which financial statements are furnished
         by the Borrowers to the Administrative Agent and each Lender for the
         fiscal quarter most recently ended as follows:

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                                                         Base Rate      LIBOR
                                                          Advance      Advance
                                                         Applicable   Applicable
                         Leverage Ratio                    Margin       Margin
                         --------------                    ------       ------

         A.  Greater than 7.00 to 1.00                     2.250%       3.250%

         B.  Greater than 6.50 to 1.00, but less than
             or equal to 7.00 to 1.00                      2.000%       3.000%

         C.  Greater than 6.00 to 1.00, but less than
             or equal to 6.50 to 1.00                      1.750%       2.750%

         D.  Greater than 5.00 to 1.00, but less than
             or equal to 6.00 to 1.00                      1.500%       2.500%

         E.  Greater than 4.00 to 1.00, but less than
             or equal to 5.00 to 1.00                      1.250%       2.250%

         F.  Less than or equal to 4.00 to 1.00            1.000%       2.000%

         Notwithstanding the foregoing, the Applicable Margin with respect to
         Advances under the Revolving Loan Commitments and the Term Loan A
         Commitments from the effective date of the Seventh Amendment hereto
         dated as of October 18, 2002 through and including September 30, 2003
         shall not be less than (A) with respect to Base Rate Advances, 1.500%
         and (B) with respect to LIBOR Advances, 2.500%.

                  (ii) Term Loan B Loans. With respect to any Advance under the
         Term Loan B Commitments, the Applicable Margin shall be, (a) with
         respect to Base Rate Advances, 2.500%, and (b) with respect to LIBOR
         Advances, 3.500%."

         (ii) Amendment to Section 2.7. Section 2.7(b)(x) of the Loan Agreement,
Incremental Facility Maturity Date, is hereby deleted in its entirety.

         (iii) Amendment to Section 2.15. Section 2.15 of the Loan Agreement,
Incremental Facility Advances, is hereby deleted in its entirety.

         (c) Amendments to Article 7.

         (i) Amendments to Section 7.6. Section 7.6 of the Loan Agreement,
Investments and Acquisitions, is hereby further amended by deleting such section
in its entirety and substituting in lieu thereof the following:

                  "Section 7.6 Investments and Acquisitions. The Borrowers shall
         not, and shall not permit any of the Restricted Subsidiaries to,
         directly or indirectly, make any loan or advance, or otherwise acquire
         for consideration evidences of Indebtedness, capital

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<PAGE>

         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 or Investment; provided, however, that the
         Borrowers and the Restricted Subsidiaries may:

                  (a) directly or through a brokerage account or investment
         advisor (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 and other short-term obligations and business
         savings accounts issued by corporations, each of which shall have a
         combined net worth of at least $100,000,000.00 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 whose issuer is, at the time of
         purchase, rated "P-2" or better by Moody's or "A-2" or better by
         Standard and Poor's; (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) a
         United States national or state bank (or any domestic branch of a
         foreign bank) subject to supervision and examination by federal or
         state banking or depository institution authorities and having capital,
         surplus and undivided profits totaling more than $100,000,000.00 and
         rated "A" or better by Moody's or Standard and Poor's, or (B) a
         Broker/Dealer, and (iv) invest in money market funds having a rating
         from Moody's and Standard and Poor's in the highest investment category
         granted thereby;

                  (b) so long as no Default then exists or would be caused
         thereby, establish Unrestricted Subsidiaries and make Investments in
         (i) such Unrestricted Subsidiaries (in addition to Investments
         permitted under Section 7.6(e), (g) and (j) hereof), (ii) [reserved]
         and (iii) Persons (other than Verestar, Inc. or its Subsidiaries)
         primarily engaged in domestic and foreign communications tower and
         tower related businesses (but not Teleport Businesses), directly or
         indirectly; provided that, after giving effect to such additional
         Investment, the aggregate Net Investment Amount made pursuant to the
         provisions of this Section 7.6(b) shall not exceed, from and after the
         effective date of the Seventh Amendment hereto dated as of October 18,
         2002, $50,000,000.00 at any time; provided further that, in the case of
         Investments made pursuant to clause (iii) of this Section 7.6(b), the
         Parent, any Borrower or any of the Restricted Subsidiaries has executed
         a binding acquisition, merger, lease/sublease or management agreement
         with such Person and that notwithstanding the foregoing Unrestricted
         Subsidiaries may make Investments and Acquisitions otherwise prohibited
         under this Section 7.6 hereof (provided, however, that Unrestricted
         Subsidiaries (1) may not make Investments in Verestar, Inc. or its
         Subsidiaries and (2) shall, from and after the effective date of the
         Seventh Amendment hereto dated as of October 18, 2002, make Investments
         only in Persons primarily engaged in domestic and foreign
         communications tower and tower related businesses (but not Teleport
         Businesses));

                  (c) so long as no Default then exists or would be caused
         thereby, and subject to compliance with Section 5.13 hereof, make
         Acquisitions; provided, however,

                                       4

<PAGE>

         that the Borrowers and the Restricted Subsidiaries may not make any
         Acquisitions of (i) tower management businesses, (ii) tower site
         management businesses or (iii) Teleport Businesses;

                  (d) [Reserved];

                  (e) make Investments consisting of the Sconnix Note;

                  (f) [Reserved];

                  (g) so long as no Default then exists or would be caused
         thereby, make loans to 116 Huntington in an aggregate amount not to
         exceed at any time outstanding $2,700,000;

                  (h) so long as no Default then exists or would be caused
         thereby, (i) make loans and advances to employees of the Parent, any
         Borrower or any of the Restricted Subsidiaries in the ordinary course
         of business and (ii) receive notes from employees in an amount not to
         exceed $5,000,000.00 in the aggregate outstanding at any time in
         connection with the exercise of stock options;

                  (i) [Reserved]; and

                  (j) all Investments made by the Borrowers and their
         Subsidiaries in Verestar, Inc. and its Subsidiaries on or prior to the
         date of the Seventh Amendment hereto dated as of October 18, 2002;
         provided, that after the date of the Seventh Amendment hereto dated as
         of October 18, 2002, so long as no Default then exists or would be
         caused thereby, the Borrowers and their Subsidiaries may make secured
         loans (but not investments) in an aggregate amount at any one time
         outstanding not to exceed $25,000,000 to Verestar, Inc. and its
         Subsidiaries so long as the notes evidencing such loans are pledged to
         the Administrative Agent as Collateral.

         Notwithstanding the limitations set forth elsewhere in this Section
         7.6, the Borrowers and the Restricted Subsidiaries may make
         Acquisitions and Investments using Capital Stock of the Parent in lieu
         of cash (and the value of such Capital Stock shall be excluded from the
         monetary limitations set forth above in this Section 7.6)."

         (ii) Amendment to Section 7.8. Section 7.8 of the Loan Agreement,
Leverage Ratio, is hereby amended by deleting such section in its entirety and
substituting in lieu thereof the following:

                  "Section 7.8 Leverage Ratio. (a) As of the end of any calendar
         quarter, (b) at the time of any Advance hereunder (after giving effect
         to such Advance) and (c) at the time of the issuance of any Letter of
         Credit (after giving effect to such Letter of Credit), the Borrowers
         shall not permit the Leverage Ratio to exceed the ratios set forth
         below during the periods indicated:

                                       5

<PAGE>

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

         July 1, 2002 through
         September 30, 2002                                   6.75 to 1.00

         October 1, 2002 through
         March 31, 2003                                       6.00 to 1.00

         April 1, 2003 through
         September 30, 2003                                   5.50 to 1.00

         October 1, 2003 through
         March 31, 2004                                       4.75 to 1.00

         April 1, 2004 through
         September 30, 2004                                   4.25 to 1.00

         October 1, 2004 through
         March 31, 2005                                       3.75 to 1.00

         April 1, 2005 and thereafter                        3.50 to 1.00"

         (iii) Amendment to Section 7.10. Section 7.10 of the Loan Agreement,
Annualized Operating Cash Flow to Pro Forma Debt Service, is hereby amended by
deleting such section in its entirety and substituting in lieu thereof the
following:

                  "Section 7.10 Annualized Operating Cash Flow to Pro Forma Debt
         Service. (a) As of the end of any calendar quarter, (b) at the time of
         any Advance hereunder (after giving effect to such Advance) and (c) at
         the time of the issuance of any Letter of Credit (after giving effect
         to such Letter of Credit), the Borrowers, on a consolidated basis,
         shall not permit the ratio of (i) Annualized Operating Cash Flow for
         such fiscal quarter or, if applicable, the most recently completed
         fiscal quarter to (ii) Pro Forma Debt Service on such date to be less
         than the ratio for such quarter as set forth below:

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

         Agreement Date
         through September 30, 2002                            1.10:1.00

         October 1, 2002
         and thereafter                                       1.00:1.00"

                                       6

<PAGE>

         (d) Amendment to Article 8. Section 8.1(q) of the Loan Agreement, is
hereby amended by deleting such subsection in its entirety and substituting in
lieu thereof the following:

                  "(q) the Parent shall sell or issue any Capital Stock (other
         than net proceeds in an amount not to exceed $2,000,000.00 in the
         aggregate after the Agreement Date from the sale of securities in
         connection with any employee stock option plan of the Parent or any of
         its Subsidiaries) or Indebtedness for cash, the net proceeds of which
         are not contributed as equity to the Borrowers, other than Capital
         Stock issued in connection with an Acquisition permitted hereunder or
         Indebtedness for Money Borrowed permitted under Section 8.1(p)(iii)
         hereof."

         2. Amendments to Loan Documents.

         (a) Amendment to Security Agreement of Verestar. Section 7 of the
Security Agreement of Verestar, Covenants Regarding Contracts, Other Contracts
and Leases, is hereby amended by deleting such section in its entirety and
substituting in lieu thereof the following:

                  "7. [Reserved]."

         (b) Amendments to Subsidiary Security Agreements. Section 8 of each of
the Subsidiary Security Agreements of the Subsidiaries of Verestar, Covenants
Regarding Contracts, Other Contracts and Leases, is hereby amended by deleting
such section in its entirety and substituting in lieu thereof the following:

                  "8. [Reserved]."

         (c) Amendment to Loan Documents.

         (i) No Subsidiary of Verestar shall be deemed to be a "Restricted
Subsidiary" or part of the "Restricted Subsidiaries" respectively.

         (ii) None of Verestar or any of its Subsidiaries shall be deemed to be
an "ERISA Affiliate" or part of the "ERISA Affiliates" respectively.
Notwithstanding anything to the contrary in this Amendment, Verestar shall not,
and shall not permit any of its Subsidiaries to (a) adopt any new Plan (as
defined in the Loan Agreement) after the date hereof, (b) enter into any
Multiemployer Plan (as defined in the Loan Agreement), (c) make any changes to
the terms of a Plan in which their employees currently participate that would
materially increase the cost of such Plan to Verestar or its Subsidiaries or (d)
except to the extent otherwise permitted under Applicable Law, permit the assets
of any of their respective Plans (as defined in the Loan Agreement) to be less
than the amount necessary to provide all accrued benefits under such Plans.

         3. Verestar Acknowledgements.

                                       7

<PAGE>

         (a) Verestar hereby acknowledges that on or prior to the date hereof
that it has made the determination that the Parent and the Borrowers have made
investments of cash and assets in Verestar in the aggregate amount of
approximately $550,000,000.00, a portion or a significant portion of which was
made with proceeds from Advances made under the Loan Agreement. Verestar hereby
further acknowledges that prior to the date hereof, Verestar was a "Borrower"
under the Loan Agreement and a guarantor pursuant to that certain Borrower's
Guaranty dated as of March 26, 2001 (the "Verestar Guaranty"), that the
aggregate principal amount of Loans outstanding under the Loan Agreement as of
the date hereof is $1,519,162,097.00, and that Verestar, as a co-Borrower, is
jointly and severally liable for such Loans as a co-Borrower, all of which
remain outstanding as of the date hereof. Verestar hereby acknowledges and
agrees that it remains the obligor of the Loans, that it remains liable to the
Lenders for the repayment of the Loans (together with interest thereon and
including, without limitation, 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 any Borrower, whether or not such claim is
allowed in such bankruptcy action) and any Obligations under the Loan Agreement
incurred in connection with or arising out of all Loans outstanding under the
Loan Agreement remain subject to repayment by Verestar as a co-Borrower pursuant
to the terms and conditions of the Loan Agreement applicable to Loans made under
the Loan Agreement. Verestar hereby agrees that nothing set forth in this
Amendment shall be deemed to release Verestar from any obligations and/or
Obligations that it may have with respect to the Loans or otherwise under the
Verestar Guaranty. Furthermore, Verestar agrees that it will remain bound by
Sections 7.1, 7.2, 7.3, 7.5, 7.6, 7.7, 7.12, and 7.14 of the Loan Agreement
(except for loans from and Liens in favor of the Borrowers or any Restricted
Subsidiary). Each of Verestar and the Parent agrees that it shall be a condition
of any release of any Loan Documents or Liens thereunder in connection with any
sale or disposition of the stock or assets of Verestar or any of its
Subsidiaries that all of the Net Proceeds of such sale or disposition be paid to
the Administrative Agent to be applied in accordance with Section 2.7(b)(iii) of
the Loan Agreement, Repayments and Prepayments, Unreinvested Net Proceeds from
Asset Sales and Insurance and Condemnation Proceedings (without giving effect to
any reinvestment period under the Loan Agreement). Upon the receipt by the
Administrative Agent of the Net Proceeds of any sale or disposition of the
Capital Stock of Verestar or its Subsidiaries or any assets of Verestar or its
Subsidiaries, the Administrative Agent and the Lenders shall, at Verestar's
expense, take such actions as Verestar reasonably requests to cause Verestar and
its Subsidiaries to be released from its obligations under the Verestar Guaranty
and the Verestar Subsidiary Guaranties, respectively or any other Loan Documents
to which it is a party and any Liens thereunder. For the purposes of Sections
8.1(e), 8.1(l) and 8.1(m) of the Loan Agreement, the Loan Documents to which
Verestar and its Subsidiaries are party shall not be deemed to be "Loan
Documents" or "Security Documents."

         (b) The Parent, the Borrowers and Verestar hereby represent and warrant
that there are no obligations of Verestar with respect to which any of the
Parent or the Borrowers are obligors or guarantors except as disclosed on
Schedule 1 attached hereto. The Majority Lenders hereby acknowledge and agree
that the guaranties existing as of the date hereof set forth on Schedule 1
attached hereto shall constitute permitted Guaranties under the Loan Agreement.

                                       8

<PAGE>

         (c) The Parent hereby confirms that as of the date hereof Verestar is a
wholly-owned direct Subsidiary of the Parent.

         (d) Verestar hereby confirms that the Verestar Guaranty to which it is
a party or otherwise bound will continue to guarantee to the fullest extent
possible in accordance with the Verestar Guaranty the payment and performance of
all "Guarantied Obligations" under the Verestar Guaranty, including without
limitation the payment and performance of all Obligations of the Borrowers now
or hereafter existing under or in respect of the Loan Agreement and the Notes
defined therein.

         (e) Verestar acknowledges and agrees that the Verestar Guaranty and any
other Loan Documents to which it is a party or otherwise bound shall continue in
full force and effect and that all of its obligations thereunder shall be valid
and enforceable, 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, and shall not be impaired or
limited by the execution or effectiveness of this Amendment. Verestar represents
and warrants that all representations and warranties contained in the Loan
Agreement, this Amendment, the Verestar Guaranty and any other Loan Documents to
which it is a party or otherwise bound are true, correct and complete in all
material respects on and as of the date hereof to the same extent as though made
on and as of that date, except to the extent such representations and warranties
specifically relate to an earlier date, in which case they were true, correct
and complete in all material respects on and as of such earlier date.

         (f) Verestar acknowledges and agrees that nothing in the Loan
Agreement, this Amendment or any other Loan Document shall be deemed to require
the consent of Verestar to any future amendments to the Loan Agreement.

         4. Verestar Subsidiary Acknowledgments.

         (a) Each of Maritime Telecommunications Network, Inc., Verestar
International, Inc. and Verestar Networks, Inc. are collectively referred to
herein as the "Verestar Subsidiary Guarantors", and the Subsidiary Guaranties
executed by the Verestar Subsidiary Guarantors are collectively referred to
herein as the "Verestar Subsidiary Guaranties".

         (b) Each Verestar Subsidiary Guarantor hereby acknowledges that it has
reviewed the terms and provisions of the Loan Agreement and this Amendment. Each
Verestar Subsidiary Guarantor hereby confirms that the Verestar Subsidiary
Guaranty to which it is a party or otherwise bound will continue to guarantee,
as the case may be, to the fullest extent possible in accordance with such
Verestar Subsidiary Guaranty the payment and performance of all "Guarantied
Obligations" under each of the Verestar Subsidiary Guaranties, as the case may
be (in each case as such term is defined in the applicable Verestar Subsidiary
Guaranty), including without limitation the payment and performance of all
Obligations of the Borrowers now or hereafter existing under or in respect of
the Loan Agreement and the Notes defined therein.

                                       9

<PAGE>

         (c) Each Verestar Subsidiary Guarantor acknowledges and agrees that any
of the Loan Documents to which it is a party or otherwise bound shall continue
in full force and effect and that all of its obligations thereunder shall be
valid and enforceable, 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, and shall not be impaired or
limited by the execution or effectiveness of this Amendment. Each Verestar
Subsidiary Guarantor represents and warrants that all representations and
warranties contained in the Loan Agreement, this Amendment and any other Loan
Document to which it is a party or otherwise bound are true, correct and
complete in all material respects on and as of the date hereof to the same
extent as though made on and as of that date, except to the extent such
representations and warranties specifically relate to an earlier date, in which
case they were true, correct and complete in all material respects on and as of
such earlier date.

         (d) Each Verestar Subsidiary Guarantor acknowledges and agrees that (i)
notwithstanding the conditions to effectiveness set forth in this Amendment,
such Verestar Subsidiary Guarantor is not required by the terms of the Loan
Agreement or any other Loan Document to consent to the amendments of the Loan
Agreement effected pursuant to this Amendment and (ii) nothing in the Loan
Agreement, this Amendment or any other Loan Document shall be deemed to require
the consent of such Verestar Subsidiary Guarantor to any future amendments to
the Loan Agreement.

         5. No Other Amendments. Except for the amendments set forth above, the
text of the Loan Agreement and all other Loan Documents shall remain unchanged
and in full force and effect. No amendment, waiver or consent by the
Administrative Agent, the Issuing Bank or the Lenders under the Loan Agreement
or any other Loan Document is granted or intended except as expressly set forth
herein, and the Administrative Agent, the Issuing Bank and the Lenders expressly
reserve the right to require strict compliance in all other respects (whether or
not in connection with any Requests for Advance). Except as set forth herein,
the amendments agreed to herein shall not constitute a modification of the Loan
Agreement or any of the other Loan Documents, or a course of dealing with the
Administrative Agent, the Issuing Bank and the Lenders at variance with the Loan
Agreement or any of the other Loan Documents, such as to require further notice
by the Administrative Agent, the Issuing Bank, the Lenders or the Majority
Lenders to require strict compliance with the terms of the Loan Agreement and
the other Loan Documents in the future.

         6. Conditions Precedent. The effectiveness of this Amendment is subject
to:

         (a) receipt by the Administrative Agent of duly executed signature
pages to this Amendment from the Majority Lenders;

         (b) receipt by the Administrative Agent of duly executed signature
pages to this Amendment from the Parent, the Borrowers, Verestar, and each of
the Verestar Subsidiary Guarantors and Guarantors;

                                       10

<PAGE>

         (c) payment from funds received from the Borrowers by the
Administrative Agent to each Lender delivering executed signature pages to this
Amendment on or prior to 12 noon (New York City time), Friday, October 18, 2002
of an amendment fee equal to one quarter of one percent (0.25%) of the amount of
Term Loan A Loans, Term Loan B Loans and Revolving Loan Commitments held by such
Lender; and

         (d) the representations and warranties contained in Article 4 of the
Loan Agreement and contained in the other Loan Documents remaining true and
correct as of the date hereof, both before and after giving effect to this
Amendment, except to the extent previously fulfilled in accordance with the
terms of the Loan Agreement or such other Loan Document, as applicable, or to
the extent relating specifically to the earlier date. No Default or Event of
Default now exists or will be caused hereby.

         7. Counterparts. This Amendment 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.

         8. Governing Law. This Amendment shall be construed in accordance with
and governed by the laws of the State of New York.

         9. Severability. Any provision of this Amendment which is prohibited or
unenforceable 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.

         10. Guarantor Acknowledgment.

         (a) Each of ATC GP, Inc., ATC Operating, Inc., ATC LP, Inc., ATS/PCS,
LLC, OmniAmerica Holdings Corporation, OmniAmerica Towers, Inc., New Loma
Communications, Inc., ATC Tower Services, Inc., Comm Site International, Inc.,
Comm Site Towers, Inc., US Sitelease, Inc., American Tower PA LLC, Unisite,
Inc., American Tower Delaware Corporation, American Tower Management, Inc., ATC
Midwest, LLC, Telecom Towers, LLC, Shreveport Tower Company, American Tower
Trust #1, ATC South LLC, MHB Tower Rentals of America, LLC, ATC International
Holding Corp., Flash Technology International, Inc., American Tower Trust #2,
Kline Iron & Steel Co., Inc., Carolina Towers, Inc., ATC Mexico Holding Corp.,
ATC MexHold, Inc. and ATC South America Holding Corp. are collectively referred
to herein as the "Guarantors," and the Guaranties executed by the Guarantors are
collectively referred to herein as the "Guaranties."

         (b) Each Guarantor hereby acknowledges that it has reviewed the terms
and provisions of the Loan Agreement and this Amendment. Each Guarantor hereby
confirms that the Guaranty to which it is a party or otherwise bound will
continue to guarantee, as the case may be, to the fullest extent possible in
accordance with such Guaranty the payment and performance of all "Guarantied
Obligations" under each of the Guaranties, as the case may be (in each case as
such term is defined in the applicable Guaranty), including without limitation
the

                                       11

<PAGE>

payment and performance of all Obligations of the Borrowers now or hereafter
existing under or in respect of the Loan Agreement and the Notes defined
therein.

         (c) Each Guarantor acknowledges and agrees that any of the other Loan
Documents to which it is a party or otherwise bound shall continue in full force
and effect and that all of its obligations thereunder shall be valid and
enforceable, 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, and shall not be impaired or
limited by the execution or effectiveness of this Amendment. Each Guarantor
represents and warrants that all representations and warranties contained in the
Loan Agreement, this Amendment and any other Loan Documents to which it is a
party or otherwise bound are true, correct and complete in all material respects
on and as of the date hereof to the same extent as though made on and as of that
date, except to the extent such representations and warranties specifically
relate to an earlier date, in which case they were true, correct and complete in
all material respects on and as of such earlier date.

         (d) Each Guarantor acknowledges and agrees that (i) notwithstanding the
conditions to effectiveness set forth in this Amendment, such Guarantor is not
required by the terms of the Loan Agreement or any other Loan Document to
consent to the amendments of the Loan Agreement effected pursuant to this
Amendment and (ii) nothing in the Loan Agreement, this Amendment or any other
Loan Document shall be deemed to require the consent of such Guarantor to any
future amendments to the Loan Agreement.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

                                       12

<PAGE>

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

BORROWERS:              AMERICAN TOWER, L.P., a Delaware limited partnership

                        By ATC GP INC., its General Partner

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        AMERICAN TOWERS, INC., a Delaware corporation

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        TOWERSITES MONITORING, INC., a Delaware corporation

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        AMERICAN TOWER INTERNATIONAL, INC., a
                                        Delaware corporation

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                                Signature Page 1

<PAGE>

PARENT:                 AMERICAN TOWER CORPORATION, a Delaware corporation

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

VERESTAR:               VERESTAR, INC., a Delaware corporation

                        By        //Matthew Petzold//
                             --------------------------------------------------
                             Name:  Matthew Petzold
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                                Signature Page 2

<PAGE>

ADMINISTRATIVE AGENT
AND LENDERS:            TORONTO DOMINION (TEXAS), INC.,
                        as Administrative Agent and as a Lender

                        By:       //Jim Bridwell//
                             --------------------------------------------------
                             Name:    Jim Bridwell
                                  ---------------------------------------------
                             Title:    Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                                Signature Page 3

<PAGE>

                        ADDISON CDO, LIMITED (#1279)
                        By:  Pacific Investment Management Company, LLC,
                             as its Investment Advisor

                        By:       //Mohan V. Phansalkar//
                             ---------------------------------------------------
                             Name:    Mohan V. Phansalkar
                                  ----------------------------------------------
                             Title:    Executive Vice President
                                   ---------------------------------------------

                        ATHENA CDO, LIMITED (#1277)
                        By:  Pacific Investment Management Company, LLC,
                             as its Investment Advisor

                        By:       //Mohan V. Phansalkar//
                             ---------------------------------------------------
                             Name:    Mohan V. Phansalkar
                                  ----------------------------------------------
                             Title:    Executive Vice President
                                   ---------------------------------------------

                        CAPTIVA III FINANCE LTD. (Acct 275),
                        As advised by Pacific Investment Management Company, LLC

                        By:       //David Dyer//
                             ---------------------------------------------------
                             Name:    David Dyer
                                  ----------------------------------------------
                             Title:    Director
                                   ---------------------------------------------

                        CAPTIVA IV FINANCE LTD. (Acct 1275),
                        As advised by Pacific Investment Management Company, LLC

                        By:       //David Dyer//
                             ---------------------------------------------------
                             Name:    David Dyer
                                  ----------------------------------------------
                             Title:    Director
                                   ---------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                                Signature Page 4

<PAGE>

                        JISSEKIKUN FUNDING, LTD. (#1288)
                        By:  Pacific Investment Management Company, LLC, as its
                             Investment Advisor

                             By:      //Mohan V. Phansalkar//
                                ------------------------------------------------
                             Name:    Mohan V. Phansalkar
                                  ----------------------------------------------
                             Title:    Executive Vice President
                                   ---------------------------------------------

                        ROYALTON COMPANY (#280)
                        By:  Pacific Investment Management Company, LLC, as its
                             Investment Advisor

                             By:      //Mohan V. Phansalkar//
                                ------------------------------------------------
                             Name:    Mohan V. Phansalkar
                                  ----------------------------------------------
                             Title:    Executive Vice President
                                   ---------------------------------------------

                        SEQUILS-MAGNUM, LTD (#1280)
                        By:  Pacific Investment Management Company, LLC, as its
                             Investment Advisor

                             By:      //Mohan V. Phansalkar//
                                ------------------------------------------------
                             Name:    Mohan V. Phansalkar
                                  ----------------------------------------------
                             Title:    Executive Vice President
                                   ---------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                                Signature Page 5

<PAGE>

                        AERIES FINANCE-II, LTD.
                        By:  INVESCO Senior Secured Management, Inc., as
                             Sub-Managing Agent

                             By:      //Scott Baskind//
                                -----------------------------------------------
                             Name:    Scott Baskind
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                        AIM FLOATING RATE FUND
                        By:  INVESCO Senior Secured Management, Inc., As
                             Attorney in fact

                             By:      //Scott Baskind//
                                -----------------------------------------------
                             Name:    Scott Baskind
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                        AMARA-1 FINANCE, LTD.
                        By:  INVESCO Senior Secured Management, Inc. As
                             Financial Manager

                             By:      //Scott Baskind//
                                -----------------------------------------------
                             Name:    Scott Baskind
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                        AMARA 2 FINANCE, LTD.
                        By:  INVESCO Senior Secured Management, Inc., As
                             Financial Manager

                             By:      //Scott Baskind//
                                -----------------------------------------------
                             Name:    Scott Baskind
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                        AVALON CAPITAL LTD.
                        By:  INVESCO Senior Secured Management, Inc., as
                             Portfolio Advisor

                             By:      //Scott Baskind//
                                -----------------------------------------------
                             Name:    Scott Baskind
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                                Signature Page 6

<PAGE>

                        AVALON CAPITAL LTD. 2
                        By:  INVESCO Senior Secured Management, Inc., as
                             Portfolio Advisor

                             By:      //Scott Baskind//
                                -----------------------------------------------
                             Name:    Scott Baskind
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                        CERES II FINANCE LTD.
                        By:  INVESCO Senior Secured Management, Inc., as Sub-
                             Managing Agent (Financial)

                             By:      //Scott Baskind//
                                -----------------------------------------------
                             Name:    Scott Baskind
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                        CHARTER VIEW PORTFOLIO
                        By:  INVESCO Senior Secured Management, Inc., as
                             Investment Advisor

                             By:      //Scott Baskind//
                                -----------------------------------------------
                             Name:    Scott Baskind
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                        DIVERSIFIED CREDIT PORTFOLIO LTD.
                        By:  INVESCO Senior Secured Management, Inc., as
                             Investment Advisor

                             By:      //Scott Baskind//
                                -----------------------------------------------
                             Name:    Scott Baskind
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                        INVESCO EUROPEAN CDO I S.A.
                        By:  INVESCO Senior Secured Management, Inc. as
                             Collateral Manager

                             By:      //Scott Baskind//
                                -----------------------------------------------
                             Name:    Scott Baskind
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                                Signature Page 7

<PAGE>

                        JPMORGAN CHASE BANK, as a Lender

                        By:           //James L. Stone//
                             --------------------------------------------------
                             Name:   James L. Stone
                                   --------------------------------------------
                             Title:     Managing Director
                                    -------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                                Signature Page 8

<PAGE>

                        TRITON CDO IV, LIMITED
                        By:  INVESCO Senior Secured Management, Inc., as
                             Investment Advisor

                        By:       //Scott Baskind//
                             --------------------------------------------------
                             Name:    Scott Baskind
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                        SEQUILS-LIBERTY, LTD.
                        By:  INVESCO Senior Secured Management, Inc., as
                             Collateral Manager

                        By:       //Scott Baskind//
                             --------------------------------------------------
                             Name:    Scott Baskind
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                                Signature Page 9

<PAGE>

                        AIMCO CDO SERIES 2000-A, as a Lender

                        By:       //Chris Goergen//
                             --------------------------------------------------
                             Name:    Chris Goergen
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                        By:       //Jerry D. Zinkula//
                             --------------------------------------------------
                             Name:    Jerry D. Zinkula
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                        AIMCO CLO, SERIES 2001-A, as a Lender

                        By:       //Chris Goergen//
                             --------------------------------------------------
                             Name:    Chris Goergen
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                        By:       //Jerry D. Zinkula//
                             --------------------------------------------------
                             Name:    Jerry D. Zinkula
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                        ALLSTATE LIFE INSURANCE COMPANY, as a Lender

                        By:       //Chris Goergen//
                             --------------------------------------------------
                             Name:    Chris Goergen
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                        By:       //Jerry D. Zinkula//
                             --------------------------------------------------
                             Name:    Jerry D. Zinkula
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 10

<PAGE>

                        ALLFIRST BANK, as a Lender

                        By        //W. Blake Hampson//
                             --------------------------------------------------
                             Name:  W. Blake Hampson
                                  ---------------------------------------------
                             Title:    Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 11

<PAGE>

                        APEX (TRIMARAN) CDO I, LTD., as a Lender
                        By: Trimaran Advisors, L.L.C.

                        By:       //David Millison//
                             ---------------------------------------------------
                             Name:  David Millison
                                  ----------------------------------------------
                             Title: Trimaran Advisors, L.L.C.-Managing Director
                                   ---------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 12

<PAGE>

                        SIERRA CLO I, LTD., as a Lender
                        By: Centre Pacific LLC

                        By:       //John M. Casparian //
                             --------------------------------------------------
                             Name:   John M. Casparian
                                  ---------------------------------------------
                             Title:    Chief Operating Officer
                                  ---------------------------------------------
                                    Centre Pacific LLC (Manager)

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 13

<PAGE>

                        ENDURANCE CLO I, LTD.
                        c/o: ING Capital Advisors LLC, as Collateral Manager

                        By:       //Gordon R. Cook//
                             ---------------------------------------------------
                             Name:    Gordon Cook
                                  ----------------------------------------------
                             Title:    Senior Vice President & Portfolio Manager
                                   ---------------------------------------------

                        ARCHIMEDES FUNDING, L.L.C.
                        By: ING Capital Advisors LLC, as Collateral Manager

                        By:       //Gordon R. Cook//
                             ---------------------------------------------------
                             Name:    Gordon Cook
                                  ----------------------------------------------
                             Title:    Senior Vice President & Portfolio Manager
                                   ---------------------------------------------

                        ARCHIMEDES FUNDING II, LTD.
                        By: ING Capital Advisors LLC, as Collateral Manager

                        By:       //Gordon R. Cook//
                             ---------------------------------------------------
                             Name:    Gordon Cook
                                  ----------------------------------------------
                             Title:    Senior Vice President & Portfolio Manager
                                   ---------------------------------------------

                        ARCHIMEDES FUNDING III, LTD.
                        By: ING Capital Advisors LLC, as Collateral Manager

                        By:       //Gordon R. Cook//
                             ---------------------------------------------------
                             Name:    Gordon Cook
                                  ----------------------------------------------
                             Title:    Senior Vice President & Portfolio Manager
                                   ---------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 14

<PAGE>

                        ARCHIMEDES FUNDING IV (CAYMAN), LTD.
                        By: ING Capital Advisors LLC, as Collateral Manager

                        By:       //Gordon R. Cook//
                             ---------------------------------------------------
                             Name:    Gordon Cook
                                  ----------------------------------------------
                             Title:    Senior Vice President & Portfolio Manager
                                   ---------------------------------------------

                        NEMEAN CLO, LTD.
                        By: ING Capital Advisors LLC, as Investment Manager

                        By:       //Gordon R. Cook//
                             ---------------------------------------------------
                             Name:    Gordon Cook
                                  ----------------------------------------------
                             Title:    Senior Vice President & Portfolio Manager
                                   ---------------------------------------------

                        BALANCED HIGH YIELD FUND I, LTD.
                        By: ING Capital Advisors LLC, as Asset Manager

                        By:       //Gordon R. Cook//
                             ---------------------------------------------------
                             Name:    Gordon Cook
                                  ----------------------------------------------
                             Title:    Senior Vice President & Portfolio Manager
                                   ---------------------------------------------

                        BALANCED HIGH YIELD FUND II, LTD.
                        By: ING Capital Advisors LLC, as Asset Manager

                        By:       //Gordon R. Cook//
                             ---------------------------------------------------
                             Name:    Gordon Cook
                                  ----------------------------------------------
                             Title:    Senior Vice President & Portfolio Manager
                                   ---------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 15

<PAGE>

                        ING-ORYX CLO, LTD.
                        By: ING Capital Advisors LLC, as Collateral Manager

                        By:       //Michael J. Campbell//
                             ---------------------------------------------------
                             Name:    Michael J. Campell
                                  ----------------------------------------------
                             Title:    Managing Director
                                   ---------------------------------------------

                        SEQUILS-ING I (HBDGM), LTD.
                        By: ING Capital Advisors LLC, as Collateral Manager

                        By:       //Gordon R. Cook//
                             ---------------------------------------------------
                             Name:    Gordon Cook
                                  ----------------------------------------------
                             Title:    Senior Vice President & Portfolio Manager
                                   ---------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 16

<PAGE>

                        BLACKROCK SENIOR LOAN TRUST, as a Lender

                        By:       //Mark Williams//
                             --------------------------------------------------
                             Name:    Mark Williams
                                  ---------------------------------------------
                             Title:     Director
                                   --------------------------------------------

                        MAGNETITE ASSET INVESTORS, LLC, as a Lender

                        By:       //Mark Williams//
                             --------------------------------------------------
                             Name:    Mark Williams
                                  ---------------------------------------------
                             Title:     Director
                                   --------------------------------------------

                        MAGNETITE ASSET INVESTORS III, LLC, as a Lender

                        By:       //Mark Williams//
                             --------------------------------------------------
                             Name:    Mark Williams
                                  ---------------------------------------------
                             Title:     Director
                                   --------------------------------------------

                        TITANIUM CBO I, LTD., as a Lender

                        By:       //Mark Williams//
                             --------------------------------------------------
                             Name:    Mark Williams
                                  ---------------------------------------------
                             Title:     Director
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 17

<PAGE>

                        BANK OF AMERICA, N.A., as a Lender

                        By:       //Patrick Honey//
                             --------------------------------------------------
                             Name:    Patrick Honey
                                  ---------------------------------------------
                             Title:     Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 18

<PAGE>

                         BANK OF MONTREAL, as a Lender

                         By:       //N. Hashemifard //
                             --------------------------------------------------
                             Name:    Naghmeh Hashemifard
                                   --------------------------------------------
                             Title:     Director
                                    -------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 19

<PAGE>

                        THE BANK OF NEW YORK, as a Lender

                        By:       //Geoffrey C. Brooks//
                             --------------------------------------------------
                             Name:    Geoffrey C. Brooks
                                  ---------------------------------------------
                             Title:    Senior Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 20

<PAGE>

                        THE BANK OF NOVA SCOTIA, as a Lender

                        By:       //Paul A. Weissenberger//
                             --------------------------------------------------
                             Name:    P.A. Weissenberger
                                  ---------------------------------------------
                             Title:    Authorized Signatory
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 21

<PAGE>

                        BANK OF SCOTLAND, as a Lender

                        By:       //Joseph Fratus//
                             --------------------------------------------------
                             Name:    Joseph Fratus
                                  ---------------------------------------------
                             Title:    First Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 22

<PAGE>

                        DEUTSCHE BANK TRUST COMPANY AMERICAS

                        By:       //Anca Trifan//
                             --------------------------------------------------
                             Name:    Anca Trifan
                                  ---------------------------------------------
                             Title:    Director
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 23

<PAGE>

                        BAYERISCHE HYPO-UND VEREINSBANK AG,
                        NEW YORK BRANCH, as a Lender

                        By:
                             --------------------------------------------------
                             Name:
                                  ---------------------------------------------
                             Title:
                                   --------------------------------------------

                        By:
                             --------------------------------------------------
                             Name:
                                  ---------------------------------------------
                             Title:
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 24

<PAGE>

                        BEAR STEARNS & CO. INC., as a LENDER

                        By:      //Gregory Hanley//
                             --------------------------------------------------
                             Name:    Gregory Hanley
                                  ---------------------------------------------
                             Title:      Vice President
                                   --------------------------------------------

                        BEAR STEARNS CORPORATE LENDING INC., as a Lender

                        By:       //Victor Bulzacchelli//
                             --------------------------------------------------
                             Name:    Victor Bulzacchelli
                                  ---------------------------------------------
                             Title:      Authorized Agent
                                   --------------------------------------------

                        BEAR STEARNS INVESTMENT PRODUCTS INC., as a Lender

                        By:       //Gregory Hanley//
                             --------------------------------------------------
                             Name:    Gregory Hanley
                                  ---------------------------------------------
                             Title:      Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 25

<PAGE>

                        BRYN MAWR CLO, LTD.
                        By:  Deerfield Capital Management LLC, as its
                                          Collateral Manager

                        By:       //Mark E. Wittnebel//
                             ---------------------------------------------------
                             Name:    Mark E. Wittnebel
                                  ----------------------------------------------
                             Title:     Sr. Vice President
                                   ---------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 26

<PAGE>

                        CALLIDUS DEBT PARTNERS CDO FUND I, LTD., as a Lender
                        By:  Callidus Capital Management, LLC,
                             its Collateral Manager

                        By:       //Mavis Taintor//
                             --------------------------------------------------
                             Name:    Mavis Taintor
                                  ---------------------------------------------
                             Title:      Managing Director
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 27

<PAGE>

                        CARLYLE HIGH YIELD PARTNERS II, LTD., as a Lender

                        By:       //Mark Alter//
                             --------------------------------------------------
                             Name:    Mark Alter
                                  ---------------------------------------------
                             Title:      Managing Director
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 28

<PAGE>

                        CENTURION CDO II, LTD.
                        By:  American Express Asset Management Group, Inc., as
                             Collateral Manager

                        By:       //Steven B. Staver//
                             --------------------------------------------------
                             Name:    Steven B. Staver
                                  ---------------------------------------------
                             Title:      Managing Director
                                   --------------------------------------------

                        CENTURION CDO III, LIMITED
                        By:  American Express Asset Management Group, Inc., as
                             Collateral Manager

                        By:       //Steven B. Staver//
                             --------------------------------------------------
                             Name:    Steven B. Staver
                                  ---------------------------------------------
                             Title:      Managing Director
                                   --------------------------------------------

                        SEQUILS - CENTURION V, LTD.
                        By:  American Express Asset Management Group, Inc., as
                             Collateral Manager

                        By:       //Steven B. Staver//
                             --------------------------------------------------
                             Name:    Steven B. Staver
                                  ---------------------------------------------
                             Title:      Managing Director
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 29

<PAGE>

                        THE CIT GROUP/EQUIPMENT FINANCING, INC., as a Lender

                        By:       //Steven K. Reedy//
                             --------------------------------------------------
                             Name:    Steven K. Reedy
                                  ---------------------------------------------
                             Title:      Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 30

<PAGE>

                        CITADEL HILL 2000 LTD., as a Lender

                        By:       //N. Karsiotis//
                             --------------------------------------------------
                             Name:    Nicholas A. Karsiotis
                                  ---------------------------------------------
                             Title:      Authorized Signatory
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 31

<PAGE>

                        CITIZENS BANK OF MASSACHUSETTS, as successor to
                        US Trust, as a Lender

                        By:       //Hamilton H. Wood, Jr.//
                             --------------------------------------------------
                             Name:    Hamilton H. Wood, Jr.
                                  ---------------------------------------------
                             Title:    Senior Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 32

<PAGE>

                        CLYDESDALE CLO 2001-1, LTD., as a Lender
                        By:  Nomura Corporate Research and
                             Asset Management, Inc., as Collateral Manager

                        By:       //Elizabeth Maclean//
                             --------------------------------------------------
                             Name:    Elizabeth Maclean
                                  ---------------------------------------------
                             Title:      Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 33

<PAGE>

                        COBANK, ACB, as a Lender

                        By:       //Anita Youngblut//
                             -------------------------------------------------
                             Name:    Anita Youngblut
                                  --------------------------------------------
                             Title:      Vice President
                                   -------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 34

<PAGE>

                        CONTINENTAL CASUALTY COMPANY, as a Lender

                        By:       //Marilou R. McGirr//
                             ---------------------------------------------------
                             Name:    Marilou R. McGirr
                                  ----------------------------------------------
                             Title:    Vice President
                                   ---------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 35

<PAGE>

                        COOPERATIEVE CENTRALE RAIFFEISEN-BOERENLEENBANK B.A.,
                        "RABOBANK NEDERLAND", NEW YORK BRANCH, as a Lender

                        By:       //Michael R. Phelan//
                             --------------------------------------------------
                             Name:    Michael R. Phelan
                                  ---------------------------------------------
                             Title:    Executive Director
                                   --------------------------------------------

                        By:       //Edward J. Peyser//
                             --------------------------------------------------
                             Name:    Edward J. Peyser
                                  ---------------------------------------------
                             Title:     Managing Director
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 36

<PAGE>

                        CREDIT LYONNAIS NEW YORK BRANCH, as a Lender

                        By:
                             --------------------------------------------------
                             Name:
                                    -------------------------------------------
                             Title:
                                    -------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 37

<PAGE>

                        CREDIT SUISSE FIRST BOSTON, as a Lender

                        By:       //Paul J. Corona//
                             --------------------------------------------------
                             Name:    Paul J. Corona
                                  ---------------------------------------------
                             Title:     Director
                                   --------------------------------------------

                        By:       //Robert Hetu//
                             --------------------------------------------------
                             Name:    Robert Hetu
                                  ---------------------------------------------
                             Title:     Director
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 38

<PAGE>

                        CREDIT SUISSE FIRST BOSTON INTERNATIONAL, as a Lender

                        By:       //Steve Martin//
                             --------------------------------------------------
                             Name:    Steve Martin
                                  ---------------------------------------------
                             Title:     Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 39

<PAGE>

                        CSAM FUNDING II, as a Lender

                        By:       //Andrew H. Marshak//
                             --------------------------------------------------
                             Name:    Andrew H. Marshak
                                  ---------------------------------------------
                             Title:     Authorized Signatory
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 40

<PAGE>

                        CYPRESSTREE INVESTMENT PARTNERS I, LTD., as a Lender

                        By:  CypressTree Investment Management Company, Inc., as
                             Portfolio Manager

                        By:       //Michael Ashton//
                             ---------------------------------------------------
                             Name:    Michael Ashton
                                  ----------------------------------------------
                             Title:      Principal
                                   ---------------------------------------------

                        CYPRESSTREE INVESTMENT PARTNERS II, LTD., as a Lender

                        By:  CypressTree Investment Management Company, Inc., as
                             Portfolio Manager

                        By:       //Michael Ashton//
                             ---------------------------------------------------
                             Name:    Michael Ashton
                                  ----------------------------------------------
                             Title:      Principal
                                   ---------------------------------------------

                        FIRST ALLMERICA FINANCIAL LIFE INSURANCE COMPANY
                        as a Lender

                        By:       //Michael Ashton//
                             ---------------------------------------------------
                             Name:    Michael Ashton
                                  ----------------------------------------------
                             Title:      Principal
                                   ---------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 41

<PAGE>

                        DEBT STRATEGIES FUND, INC., as a Lender
                        By:  Merrill Lynch Asset Management, L.P.,
                             as Attorney In Fact

                        By:       //Greg Spencer//
                             ---------------------------------------------------
                             Name:    Greg Spencer
                                  ----------------------------------------------
                             Title:      Authorized Signatory
                                   ---------------------------------------------

                        LONGHORN CDO (CAYMAN) LTD., as a Lender
                        By:  Merrill Lynch Asset Management, L.P.,
                             as Attorney In Fact

                        By:       //Greg Spencer//
                             ---------------------------------------------------
                             Name:    Greg Spencer
                                  ----------------------------------------------
                             Title:      Authorized Signatory
                                   ---------------------------------------------

                        LONGHORN CDO II, LTD., as a Lender
                        By:  Merrill Lynch Investment Managers, L.P.,
                             as Investment Advisor

                        By:       //Greg Spencer//
                             ---------------------------------------------------
                             Name:    Greg Spencer
                                  ----------------------------------------------
                             Title:      Authorized Signatory
                                   ---------------------------------------------

                        MASTER SENIOR FLOATING RATE TRUST, as a Lender
                        By:  Merrill Lynch Investment Managers, L.P., as
                             Investment Advisor

                        By:       //Greg Spencer//
                             ---------------------------------------------------
                             Name:    Greg Spencer
                                  ----------------------------------------------
                             Title:      Authorized Signatory
                                   ---------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 42

<PAGE>

                        MERRILL LYNCH GLOBAL INVESTMENT SERIES:
                        INCOME STRATEGIES PORTFOLIO, as a Lender
                        By:  Merrill Lynch Investment Managers, L.P.,
                             as Investment Advisor

                        By:       //Greg Spencer//
                             --------------------------------------------------
                             Name:    Greg Spencer
                                  ---------------------------------------------
                             Title:      Authorized Signatory
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 43

<PAGE>

                        MERRILL LYNCH PRIME RATE PORTFOLIO, as a Lender
                        By:  Merrill Lynch Investment Managers, L.P.,
                             as Investment Advisor

                        By:       //Greg Spencer//
                             --------------------------------------------------
                             Name:    Greg Spencer
                                  ---------------------------------------------
                             Title:      Authorized Signatory
                                   --------------------------------------------

                        MERRILL LYNCH SENIOR FLOATING RATE FUND, INC.,
                        as a Lender

                        By:       //Greg Spencer//
                             --------------------------------------------------
                             Name:    Greg Spencer
                                  ---------------------------------------------
                             Title:      Authorized Signatory
                                   --------------------------------------------

                        SENIOR HIGH INCOME PORTFOLIO, INC., as a Lender

                        By:       //Greg Spencer//
                             --------------------------------------------------
                             Name:    Greg Spencer
                                  ---------------------------------------------
                             Title:      Authorized Signatory
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 44

<PAGE>

                        DEXIA CREDIT LOCAL (f/k/a CREDIT LOCAL DE FRANCE -
                        NEW YORK AGENCY), as a Lender

                        By:
                             --------------------------------------------------
                             Name:
                                  ---------------------------------------------
                             Title:
                                   --------------------------------------------

                        By:
                             --------------------------------------------------
                             Name:
                                  ---------------------------------------------
                             Title:
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 45

<PAGE>

                        DRESDNER BANK AG, NEW YORK AND GRAND CAYMAN BRANCHES,
                        as a Lender

                        By:       //Brian Schneider//
                             --------------------------------------------------
                             Name:    Brian Schneider
                                  ---------------------------------------------
                             Title:     Vice President
                                   --------------------------------------------

                        By:       //Brian Smith//
                             --------------------------------------------------
                             Name:    Brian Smith
                                  ---------------------------------------------
                             Title:     Director
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 46

<PAGE>

                        ELF FUNDING TRUST III, as a Lender
                        By:  New York Life Investment Management, LLC, as
                             attorney-in-fact

                             By:      //R.H. Dial//
                                -----------------------------------------------
                             Name:    R.H. Dial
                                  ---------------------------------------------
                             Title:      Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 47

<PAGE>

                        ERSTE BANK DER OESTERREICHISCHEN SPARKASSEN AG,
                        as a Lender

                        By:       //John Fay//
                            ---------------------------------------------------
                            Name:   John Fay
                                 ----------------------------------------------
                            Title:  Vice President-Erste Bank New York Branch
                                  ---------------------------------------------

                        By:       //John S. Runnion//
                            ---------------------------------------------------
                            Name:  John S. Runnion
                                  ----------------------------------------------
                            Title: Managing Director -Erste Bank New York Branch
                                   ---------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 48

<PAGE>

                        EATON VANCE CDO III, LTD.
                        By:  Eaton Vance Management, as Investment Advisor

                        By:       //Payson F. Swaffield//
                             --------------------------------------------------
                             Name:    Payson F. Swaffield
                                  ---------------------------------------------
                             Title:      Vice President
                                   --------------------------------------------

                        EATON VANCE INSTITUTIONAL SENIOR LOAN FUND
                        By:  Eaton Vance Management, as Investment Advisor

                             By:      //Payson F. Swaffield//
                                -----------------------------------------------
                             Name:    Payson F. Swaffield
                                  ---------------------------------------------
                             Title:      Vice President
                                   --------------------------------------------

                        EATON VANCE SENIOR INCOME TRUST
                        By:  Eaton Vance Management, as Investment Advisor

                             By:      //Payson F. Swaffield//
                                -----------------------------------------------
                             Name:    Payson F. Swaffield
                                  ---------------------------------------------
                             Title:      Vice President
                                   --------------------------------------------

                        GRAYSON & CO
                        By:  Boston Management and Research,
                             as Investment Advisor

                        By:       //Payson F. Swaffield//
                             --------------------------------------------------
                             Name:    Payson F. Swaffield
                                  ---------------------------------------------
                             Title:      Vice President
                                   --------------------------------------------

                        SENIOR DEBT PORTFOLIO
                        By:  Boston Management and Research,
                             as Investment Advisor

                        By:       //Payson F. Swaffield//
                             --------------------------------------------------
                             Name:    Payson F. Swaffield
                                  ---------------------------------------------
                             Title:      Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 49

<PAGE>

                        FC-CBO III LIMITED, as a Lender

                        By:       //Mike McCarthy//
                             --------------------------------------------
                             Name:    Mike McCarthy
                                  ---------------------------------------
                             Title:      Manager
                                   --------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 50

<PAGE>

                        BALLYROCK CDO I LIMITED, as a Lender

                        By:       //Lisa Rymut//
                             ---------------------------------------------
                             Name:    Lisa Rymut
                                  ----------------------------------------
                             Title:      Assistant Treasurer
                                   ---------------------------------------

                        FIDELITY ADVISOR SERIES II:
                        FIDELITY ADVISOR FLOATING RATE HIGH INCOME FUND,
                        as a Lender

                        By:       //John H. Costello//
                             ---------------------------------------------
                             Name:    John H. Costello
                                  ----------------------------------------
                             Title:      Assistant Treasurer
                                   ---------------------------------------

                        FIDELITY DEVONSHIRE TRUST:
                        FIDELITY EQUITY-INCOME FUND, as a Lender

                        By:       //John H. Costello//
                             ---------------------------------------------
                             Name:    John H. Costello
                                  ----------------------------------------
                             Title:      Assistant Treasurer
                                   ---------------------------------------

                        FIDELITY FIXED INCOME TRUST: FIDELITY HIGH
                        INCOME FUND, as a Lender

                        By:       //John H. Costello//
                             ---------------------------------------------
                             Name:    John H. Costello
                                  ----------------------------------------
                             Title:      Assistant Treasurer
                                   ---------------------------------------

                        VARIABLE INSURANCE PRODUCTS FUND III:
                        BALANCED PORTFOLIO, as a Lender

                        By:       //John H. Costello//
                             ---------------------------------------------
                             Name:    John H. Costello
                                  ----------------------------------------
                             Title:      Assistant Treasurer
                                   ---------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 51

<PAGE>

                        VARIABLE INSURANCE PRODUCTS FUND:
                        EQUITY-INCOME PORTFOLIO, as a Lender

                        By:       //John H. Costello//
                             -------------------------------------------
                             Name:    John H. Costello
                                  --------------------------------------
                             Title:      Assistant Treasurer
                                   -------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 52

<PAGE>

                        FIRST DOMINION FUNDING III, as a Lender

                        By:       //Andrew H. Marshak//
                             ----------------------------------------
                             Name:    Andrew H. Marshak
                                  -----------------------------------
                             Title:      Authorized Signatory
                                   ----------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 53

<PAGE>

                        WACHOVIA BANK, N. A. f/k/a
                        FIRST UNION NATIONAL BANK, as a Lender

                        By:       //Mark L. Cook //
                             ----------------------------------------------
                             Name: Mark L. Cook
                                  -----------------------------------------
                             Title:    Director
                                   ----------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 54

<PAGE>

                        FLEET NATIONAL BANK, as a Lender

                        By:       //Corrine M. Barrett//
                             -------------------------------------------
                             Name:    Corrine M. Barrett
                                  --------------------------------------
                             Title:      Senior Vice President
                                   -------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 55

<PAGE>

                        FORTIS CAPITAL CORP., as a Lender

                        By:       //Alan E. McLintock//
                             -----------------------------------------
                             Name:    Alan E. McLintock
                                  ------------------------------------
                             Title:      Managing Director
                                   -----------------------------------

                        By:       //Anthony Ciraulo//
                             -----------------------------------------
                             Name:    Anthony Ciraulo
                                  ------------------------------------
                             Title:      Assistant Vice President
                                   -----------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 56

<PAGE>

                        MIZUHO CORPORATE BANK, LTD., as a Lender

                        By:       //Atsushi Narikawa//
                             ------------------------------------------
                             Name:    Atsushi Narikawa
                                  -------------------------------------
                             Title:      Senior Vice President
                                   ------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 57

<PAGE>

                        GALAXY CLO 1999-1, LTD., as a Lender
                        By:  SAI Investment Adviser, Inc., its Collateral Agent

                        By:       //John G. Lapham, III//
                             ----------------------------------------------
                             Name:    John G. Lapham, III
                                  -----------------------------------------
                             Title:      Authorized Agent
                                   ----------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 58

<PAGE>

                        GENERAL ELECTRIC CAPITAL CORPORATION, as a Lender

                        By:       //Brian P. Ward//
                             ----------------------------------------
                             Name:    Brian P. Ward
                                  -----------------------------------
                             Title:      Manager-Operations
                                   ----------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 59

<PAGE>

                        GSC PARTNERS CDO FUND III, LIMITED, as a Lender

                        By:       //Tom Libussi//
                             --------------------------------------
                             Name:    Tom Libussi
                                  ---------------------------------
                             Title:      Managing Director
                                   --------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 60

<PAGE>

                        HARBOUR TOWN FUNDING TRUST, as a Lender

                        By:       //Ann E. Morris//
                             ----------------------------------------
                             Name:    Ann E. Morris
                                  -----------------------------------
                             Title:      Authorized Agent
                                   ----------------------------------

                        JUPITER FUNDING TRUST, as a Lender

                        By:       //Ann E. Morris//
                             ----------------------------------------
                             Name:    Ann E. Morris
                                  -----------------------------------
                             Title:      Authorized Agent
                                   ----------------------------------

                        MUIRFIELD TRADING LLC, as a Lender

                        By:       //Ann E. Morris//
                             ----------------------------------------
                             Name:    Ann E. Morris
                                  -----------------------------------
                             Title:      Assistant Vice President
                                   ----------------------------------

                        OLYMPIC FUNDING TRUST, SERIES 1999-1,
                        as a Lender

                        By:       //Ann E. Morris//
                             ----------------------------------------
                             Name:    Ann E. Morris
                                  -----------------------------------
                             Title:      Authorized Agent
                                   ----------------------------------

                        PPM SPYGLASS FUNDING TRUST, as a Lender

                        By:       //Ann E. Morris//
                             ----------------------------------------
                             Name:    Ann E. Morris
                                  -----------------------------------
                             Title:      Authorized Agent
                                   ----------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 61

<PAGE>

                        STANWICH LOAN FUNDING LLC, as a Lender

                        By:       //Ann E. Morris//
                             ----------------------------------------
                             Name:    Ann E. Morris
                                  -----------------------------------
                             Title:      Assistant Vice President
                                   ----------------------------------

                        WINGED FOOT FUNDING TRUST, as a Lender

                        By:       //Ann E. Morris//
                             ----------------------------------------
                             Name:    Ann E. Morris
                                  -----------------------------------
                             Title:      Authorized Agent
                                   ----------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 62

<PAGE>

                        HARBOURVIEW CDO II, LTD., as a Lender

                        By:
                             --------------------------------------------------
                             Name:
                                  ---------------------------------------------
                             Title:
                                   --------------------------------------------

                        HARBOURVIEW CDO IV, LTD., as a Lender

                        By:
                             --------------------------------------------------
                             Name:
                                  ---------------------------------------------
                             Title:
                                   --------------------------------------------

                        OPPENHEIMER SENIOR FLOATING RATE FUND, as a Lender

                        By:
                             --------------------------------------------------
                             Name:
                                  ---------------------------------------------
                             Title:
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 63

<PAGE>

                        BANKNORTH, N. A., as a Lender

                        By:       //Nicolas Caussade//
                             --------------------------------------------------
                             Name:    Nicolas Caussade
                                  ---------------------------------------------
                             Title:  Assistant Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 64

<PAGE>

                        IBM CREDIT CORPORATION, as a Lender

                        By:       //Thomas S. Curcio//
                             -------------------------------------------
                             Name:    Thomas S. Curcio
                                  --------------------------------------
                             Title:      Manager of Credit
                                   -------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 65

<PAGE>

                        SCUDDER FLOATING RATE FUND, as a Lender
                        (f/k/a Kemper Floating Rate Fund)

                        By:       //Kenneth Weber//
                             ----------------------------------------
                             Name:    Kenneth Weber
                                  -----------------------------------
                             Title:     Senior Vice President
                                   ----------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 66

<PAGE>

                        KEY CORPORATE CAPITAL, INC., as a Lender

                        By:
                             --------------------------------------------------
                             Name:
                                  ---------------------------------------------
                             Title:
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 67

<PAGE>

                        KZH CYPRESSTREE-1 LLC, as a Lender

                        By:       //Susan  Lee//
                             -----------------------------------------------
                             Name:    Susan Lee
                                  ------------------------------------------
                             Title:      Authorized Agent
                                   -----------------------------------------

                        KZH ING-2 LLC, as a Lender

                        By:       //Susan  Lee//
                             -----------------------------------------------
                             Name:    Susan Lee
                                  ------------------------------------------
                             Title:      Authorized Agent
                                   -----------------------------------------

                        KZH ING-3 LLC, as a Lender

                        By:       //Susan  Lee//
                             -----------------------------------------------
                             Name:    Susan Lee
                                  ------------------------------------------
                             Title:      Authorized Agent
                                   -----------------------------------------

                        KZH RIVERSIDE LLC, as a Lender

                        By:       //Susan  Lee//
                             -----------------------------------------------
                             Name:    Susan Lee
                                  ------------------------------------------
                             Title:      Authorized Agent
                                   -----------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 68

<PAGE>

                        KZH SOLEIL LLC, as a Lender

                        By:      //Susan  Lee//
                             -------------------------------------
                             Name:    Susan Lee
                                  --------------------------------
                             Title:  Authorized Agent
                                   -------------------------------

                        KZH SOLEIL-2 LLC, as a Lender

                        By:       //Susan  Lee//
                             -------------------------------------
                             Name:    Susan Lee
                                  --------------------------------
                             Title:      Authorized Agent
                                   -------------------------------

                        KZH STERLING LLC, as a Lender

                        By:       //Susan  Lee//
                             -------------------------------------
                             Name:    Susan Lee
                                  --------------------------------
                             Title:      Authorized Agent
                                   -------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 69

<PAGE>

                        LANDMARK CDO LIMITED, as a Lender
                        By:  Aladdin Asset Management LLC, as Manager

                             By:      //Gilles Marchand//
                                ---------------------------------------------
                             Name:    Gilles Marchand
                                  -------------------------------------------
                             Title:      Authorized Signatory
                                   ------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 70

<PAGE>

                        LCM I LIMITED PARTNERSHIP, as a Lender
                        By:  Lyon Capital Management LLC, as Attorney in Fact

                        By:       //Mark A. Campellone//
                             --------------------------------------------------
                             Name:   Mark A. Campellone
                                  ---------------------------------------------
                             Title:  Senior Portfolio Manager- Lyon Capital
                                   --------------------------------------------
                                     Management LLC
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 71

<PAGE>

                        METROPOLITAN LIFE INSURANCE COMPANY, as a Lender

                        By:       //James R. Dingler//
                             -------------------------------------------
                             Name:    James R. Dingler
                                  --------------------------------------
                             Title:      Director
                                   -------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 72

<PAGE>

                        ML CLO XV PILGRIM AMERICA (CAYMAN) LTD.

                        By:  ING Investments, LLC, as its investment manager

                        By:       //Jeffrey A. Bakalar//
                             --------------------------------------------------
                             Name:    Jeffrey A. Bakalar
                                  ---------------------------------------------
                             Title:      Senior Vice President
                                   --------------------------------------------

                        ML CLO XX PILGRIM AMERICA (CAYMAN) LTD.

                        By:  ING Investments, LLC, as its investment manager

                        By:       //Jeffrey A. Bakalar//
                             --------------------------------------------------
                             Name:    Jeffrey A. Bakalar
                                  ---------------------------------------------
                             Title:      Senior Vice President
                                   --------------------------------------------

                        PILGRIM CLO 1999-1 LTD.
                        By:  ING Investments, LLC, as its investment manager

                        By:       //Jeffrey A. Bakalar//
                             --------------------------------------------------
                             Name:    Jeffrey A. Bakalar
                                  ---------------------------------------------
                             Title:      Senior Vice President
                                   --------------------------------------------

                        ING PRIME RATE TRUST
                        By:  ING Investments, LLC, as its investment manager

                        By:       //Jeffrey A. Bakalar//
                             --------------------------------------------------
                             Name:    Jeffrey A. Bakalar
                                  ---------------------------------------------
                             Title:      Senior Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 73

<PAGE>

                        ING SENIOR INCOME FUND
                        By:  ING Investments, LLC, as its investment manager

                        By:       //Jeffrey A. Bakalar//
                             --------------------------------------------------
                             Name:    Jeffrey A. Bakalar
                                  ---------------------------------------------
                             Title:      Senior Vice President
                                   --------------------------------------------

                        SEQUILS-PILGRIM I, LTD.
                        By:  ING Investments, LLC, as its investment manager

                        By:       //Jeffrey A. Bakalar//
                             --------------------------------------------------
                             Name:    Jeffrey A. Bakalar
                                  ---------------------------------------------
                             Title:      Senior Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 74

<PAGE>

                        MORGAN STANLEY PRIME INCOME TRUST, as a Lender

                        By:       //Sheila A. Finnerty//
                             ---------------------------------------------
                             Name:    Sheila A. Finnerty
                                  ----------------------------------------
                             Title:      Executive Director
                                   ---------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 75

<PAGE>

                        MOUNTAIN CAPITAL CLO I, LTD., as a Lender

                        By:       //Darren P. Riley//
                             --------------------------------------------------
                             Name:    Darren P. Riley
                                  ---------------------------------------------
                             Title:      Director
                                   --------------------------------------------

                        MOUNTAIN CAPITAL CLO II, LTD., as a Lender

                        By:       //Darren P. Riley//
                             --------------------------------------------------
                             Name:    Darren P. Riley
                                  ---------------------------------------------
                             Title:      Director
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 76

<PAGE>

                        NATEXIS BANQUES POPULAIRES, as a Lender

                        By:       //Cynthia E. Sachs//
                           ----------------------------------------------------
                             Name:    Cynthia E. Sachs
                                  ---------------------------------------------
                             Title:     Vice President, Group Manager
                                   --------------------------------------------

                        By:       //Michael T. Pellerito//
                           ----------------------------------------------------
                             Name:    Michael T. Pellerito
                                  ---------------------------------------------
                             Title:    Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 77

<PAGE>

                        NATIONAL CITY BANK, as a Lender

                        By:       //Timothy J. Ambrose//
                             ---------------------------------------------
                             Name:    Timothy J. Ambrose
                                  ----------------------------------------
                             Title:      Vice President
                                   ---------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 78

<PAGE>

                        OCTAGON INVESTMENT PARTNERS II, LLC, as a Lender
                        By:  Octagon Credit Investors, LLC,
                             as sub-investment manager

                        By:       //Andrew D. Gordon//
                             ------------------------------------------------
                             Name:    Andrew D. Gordon
                                  -------------------------------------------
                             Title:      Portfolio Manager
                                   ------------------------------------------

                        OCTAGON INVESTMENT PARTNERS III, LTD., as a Lender
                        By:  Octagon Credit Investors, LLC,
                             as Portfolio Manager

                        By:       //Andrew D. Gordon//
                             ------------------------------------------------
                             Name:    Andrew D. Gordon
                                  -------------------------------------------
                             Title:      Portfolio Manager
                                   ------------------------------------------

                        OCTAGON INVESTMENT PARTNERS IV, LTD., as a Lender
                        By:  Octagon Credit Investors, LLC,
                             as Collateral Manager

                        By:       //Andrew D. Gordon//
                             ------------------------------------------------
                             Name:    Andrew D. Gordon
                                  -------------------------------------------
                             Title:      Portfolio Manager
                                   ------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 79

<PAGE>

                        PACIFICA PARTNERS I, L.P., as a Lender
                        By:  Imperial Credit Asset Management,
                             as its Investment Manager

                        By:       //Sean R. Walker//
                             -----------------------------------------
                             Name:    Sean R. Walker
                                  ------------------------------------
                             Title:      Vice President
                                   -----------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 80

<PAGE>

                        PRESIDENT & FELLOWS OF HARVARD COLLEGE, as a Lender
                        By:  Regiment Capital Management, LLC,
                             as its Investment Advisor

                        By:  Regiment Capital Advisors, LLC, its Manager and
                             pursuant to delegated authority

                        By:       //Timothy S. Peterson//
                             ---------------------------------------------------
                             Name:    Timothy S. Peterson
                                  ----------------------------------------------
                             Title:      President
                                   ---------------------------------------------

                        REGIMENT CAPITAL LTD. as a Lender
                        By:  Regiment Capital Management, LLC, as its Investment
                             Advisor
                        By:  Regiment Capital Advisors, LLC, its Manager and
                             pursuant to delegated authority

                        By:       //Timothy S. Peterson//
                             ---------------------------------------------------
                             Name:    Timothy S. Peterson
                                  ----------------------------------------------
                             Title:      President
                                   ---------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 81

<PAGE>

                        ROYAL BANK OF CANADA, as a Lender

                        By:       //John M. Crawford//
                             -----------------------------------------------
                             Name:    John M. Crawford
                                  ------------------------------------------
                             Title:      Senior Manager
                                   -----------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 82

<PAGE>

                        SANKATY ADVISORS, INC., as Collateral Manager for
                        BRANT POINT CBO 1999-1, LTD., as Term Lender

                        By        //Diane J. Exter//
                             --------------------------------------------------
                             Name:  Diane J. Exter
                                  ---------------------------------------------
                             Title:    Managing Director, Portfolio Manager
                                   --------------------------------------------

                        SANKATY ADVISORS, LLC, as Collateral Manager for
                        BRANT POINT II CBO 2000-1, LTD., as Term Lender

                        By        //Diane J. Exter//
                             --------------------------------------------------
                             Name:  Diane J. Exter
                                  ---------------------------------------------
                             Title:    Managing Director, Portfolio Manager
                                   --------------------------------------------

                        SANKATY ADVISORS, LLC, as Collateral Manager for
                        CASTLE HILL II-INGOTS, LTD., as Term Lender

                        By        //Diane J. Exter//
                             --------------------------------------------------
                             Name:  Diane J. Exter
                                  ---------------------------------------------
                             Title:    Managing Director, Portfolio Manager
                                   --------------------------------------------

                        SANKATY ADVISORS, INC., as Collateral Manager for
                        GREAT POINT CLO 1998-1 LTD., as Term Lender

                        By        //Diane J. Exter//
                             --------------------------------------------------
                             Name:  Diane J. Exter
                                  ---------------------------------------------
                             Title:    Managing Director, Portfolio Manager
                                   --------------------------------------------

                        SANKATY ADVISORS, LLC, as Collateral Manager for
                        GREAT POINT CLO 1999-1 LTD., as Term Lender

                        By        //Diane J. Exter//
                             --------------------------------------------------
                             Name:  Diane J. Exter
                                  ---------------------------------------------
                             Title:    Managing Director, Portfolio Manager
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 83

<PAGE>

                        SANKATY ADVISORS, LLC, as Collateral Manager for
                        RACE POINT CLO, LIMITED, as Term Lender

                        By        //Diane J. Exter//
                             --------------------------------------------------
                             Name:  Diane J. Exter
                                  ---------------------------------------------
                             Title:    Managing Director, Portfolio Manager
                                   --------------------------------------------

                        SANKATY HIGH YIELD ASSET PARTNERS II, L.P.

                        By        //Diane J. Exter//
                             --------------------------------------------------
                             Name:  Diane J. Exter
                                  ---------------------------------------------
                             Title:    Managing Director, Portfolio Manager
                                   --------------------------------------------

                        SANKATY HIGH YIELD PARTNERS III, L.P.

                        By        //Diane J. Exter//
                             --------------------------------------------------
                             Name:  Diane J. Exter
                                  ---------------------------------------------
                             Title:    Managing Director, Portfolio Manager
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 84

<PAGE>

                        SEABOARD CLO 2000 LTD, as a Lender

                        By:
                             --------------------------------------------------
                             Name:
                                  ---------------------------------------------
                             Title:
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 85

<PAGE>

                        SENECA CBO II, L.P., as a Lender

                        By        //Thomas N. Haag//
                             --------------------------------------------------
                             Name:  Thomas N. Haag
                                  ---------------------------------------------
                             Title:    Portfolio Manager
                                   --------------------------------------------

                        SENECA CBO III, LIMITED, as a Lender

                        By        //Thomas N. Haag//
                             --------------------------------------------------
                             Name:  Thomas N. Haag
                                  ---------------------------------------------
                             Title:    Portfolio Manager
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 86

<PAGE>

                        ROSEMONT CLO, LTD., as a Lender
                        By:  Deerfield Capital Management, L.L.C.,
                             as its Collateral Manager

                        By:       //Mark E. Wittnebel//
                             --------------------------------------------------
                             Name:    Mark E. Wittnebel
                                  ---------------------------------------------
                             Title:      Senior Vice President
                                   --------------------------------------------

                        SEQUILS-CUMBERLAND I, LTD., as a Lender
                        By:  Deerfield Capital Management, L.L.C.,
                             as its Collateral Manager

                        By:       //Mark E. Wittnebel//
                             --------------------------------------------------
                             Name:    Mark E. Wittnebel
                                  ---------------------------------------------
                             Title:      Senior Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 87

<PAGE>

                        SUNTRUST BANK, N.A. as a Lender

                        By:       //William C. Washburn, Jr.//
                             ------------------------------------------
                             Name:    William C. Washburn, Jr.
                                  -------------------------------------
                             Title:      Vice President
                                   ------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 88

<PAGE>

                        SYNDICATED LOAN FUNDING TRUST, as a Lender
                        By:  Lehman Commercial Paper, Inc.,
                             Not in its individual capacity but
                             solely as Asset Manager

                        By:       //G. Robert Berzins//
                             --------------------------------------------------
                             Name:    G. Robert  Berzins
                                  ---------------------------------------------
                             Title:      Authorized Signatory
                                   --------------------------------------------

                        LEHMAN COMMERCIAL PAPER, as a Lender

                        By:       //G. Robert Berzins//
                             --------------------------------------------------
                             Name:    G. Robert Berzins
                                  ---------------------------------------------
                             Title:      Authorized Signatory
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 89

<PAGE>

                        TEXTRON FINANCIAL CORPORATION, as a Lender

                        By:       //Matthew J. Colgan//
                             --------------------------------------------------
                             Name:    Matthew J. Colgan
                                  ---------------------------------------------
                             Title:     Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 90

<PAGE>

                        UNION BANK OF CALIFORNIA, N.A., as a Lender

                        By:       //Peter Connoy//
                             -------------------------------------------------
                             Name:    Peter Connoy
                                  --------------------------------------------
                             Title:     Vice President
                                   -------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 91

<PAGE>

                        VAN KAMPEN CLO I, LIMITED, as a Lender
                        By:  Van Kampen Management, Inc., as Collateral Manager

                        By:       //Brad Langs//
                             ---------------------------------------------------
                             Name:      Brad Langs
                                  ----------------------------------------------
                             Title:      Vice President
                                   ---------------------------------------------

                        VAN KAMPEN CLO II, LIMITED, as a Lender
                        By:  Van Kampen Management, Inc., as Collateral Manager

                        By:       //Brad Langs//
                             ---------------------------------------------------
                             Name:      Brad Langs
                                  ----------------------------------------------
                             Title:      Vice President
                                   ---------------------------------------------

                        VAN KAMPEN SENIOR INCOME TRUST, as a Lender
                        By:  Van Kampen Investment Advisory Corp.

                        By:       //Brad Langs//
                             ---------------------------------------------------
                             Name:      Brad Langs
                                  ----------------------------------------------
                             Title:      Vice President
                                   ---------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 92

<PAGE>

                        WASHINGTON MUTUAL BANK, as a Lender

                        By:       //Tony Yee//
                             --------------------------------------------------
                             Name:      Tony Yee
                                  ---------------------------------------------
                             Title:        Assistant Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 93

<PAGE>

                        WEBSTER BANK, as a Lender

                        By:       //Paul T. Savino//
                             --------------------------------------------------
                             Name:     Paul T. Savino
                                  ---------------------------------------------
                             Title:      Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 94

<PAGE>

                        NIB CAPITAL BANK N.V., as a Lender

                        By:       //Henny J. Th. Spanjaard//
                             --------------------------------------------------
                             Name:      Henny J. Th. Spanjaard
                                  ---------------------------------------------
                             Title:         Head Special Credits
                                   --------------------------------------------

                        By:       //E.M. Snatore//
                             --------------------------------------------------
                             Name:      E.M. Snatore
                                  ---------------------------------------------
                             Title:        Head Risk Management
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 95

<PAGE>

VERESTAR SUBSIDIARY     MARITIME TELECOMMUNICATIONS NETWORK, INC.
GUARANTORS:

                        By:       //Matthew Petzold//
                             --------------------------------------------------
                             Name:  Matthew Petzold
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        VERESTAR INTERNATIONAL, INC.

                        By:       //Matthew Petzold//
                             --------------------------------------------------
                             Name:  Matthew Petzold
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        VERESTAR NETWORKS, INC.

                        By:       //Matthew Petzold//
                             --------------------------------------------------
                             Name:  Matthew Petzold
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

GUARANTORS:             ATC GP, INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        ATC OPERATING, INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        ATC LP, INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 96

<PAGE>

                        ATS/PCS, LLC

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        OMNIAMERICA HOLDINGS CORPORATION

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        OMNIAMERICA TOWERS, INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        NEW LOMA COMMUNICATIONS, INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        ATC TOWER SERVICES, INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        COMM SITE INTERNATIONAL, INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 97

<PAGE>

                        COMM SITE TOWERS, INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        US SITELEASE, INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        AMERICAN TOWER PA LLC

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        UNISITE, INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        AMERICAN TOWER DELAWARE CORPORATION

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        AMERICAN TOWER MANAGEMENT, INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 98

<PAGE>

                        ATC MIDWEST, LLC

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        TELECOM TOWERS, LLC

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial
                                   --------------------------------------------

                        SHREVEPORT TOWER COMPANY

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        AMERICAN TOWER TRUST #1

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        ATC SOUTH LLC

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        MHB TOWER RENTALS OF AMERICA, LLC

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        ATC INTERNATIONAL HOLDING CORP.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                               Signature Page 99

<PAGE>

                        FLASH TECHNOLOGY INTERNATIONAL, INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        AMERICAN TOWER TRUST #2

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        KLINE IRON & STEEL CO., INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        CAROLINA TOWERS, INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        ATC MEXICO HOLDING CORP.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        ATC MEXHOLD, INC.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                        ATC SOUTH AMERICA HOLDING CORP.

                        By        //Brad Singer//
                             --------------------------------------------------
                             Name:  Brad Singer
                                  ---------------------------------------------
                             Title:  Chief Financial Officer
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                              Signature Page 100

<PAGE>

                        SALOMON BROTHERS HOLDING COMPANY, INC. as a Lender

                        By        //Pierre Batrouni//
                             --------------------------------------------------
                             Name:  Pierre Batrouni
                                  ---------------------------------------------
                             Title:    Vice President
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                              Signature Page 101

<PAGE>

                        ROBECO CDO II, LTD., as a Lender

                        By        //Harry M. Sharlach//
                             --------------------------------------------------
                             Name:  Harry M. Sharlach
                                  ---------------------------------------------
                             Title:    Director, Portfolio Manager
                                   --------------------------------------------

                                                           AMERICAN TOWER, L. P.
                                             SEVENTH AMENDMENT TO LOAN AGREEMENT
                                                              Signature Page 102

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