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                                                                   EXHIBIT 10.28



                      FOURTH AMENDMENT TO CREDIT AGREEMENT

              This FOURTH  AMENDMENT TO CREDIT  AGREEMENT (this  "Amendment") is
entered into as of March 9, 2000,  by and among  SpectraSite  Communications,
Inc., a Delaware  corporation (the ABorrower@),  SpectraSite  Holdings,  Inc., a
Delaware  corporation  ("Holdco"),  CIBC World Markets  Corp.  and Credit Suisse
First Boston,  as arrangers (the  "Arrangers"),  Credit Suisse First Boston,  as
syndication agent (the "Syndication Agent"), Canadian Imperial Bank of Commerce,
as administrative agent (the "Administrative Agent"),  Canadian Imperial Bank of
Commerce,  as  collateral  agent (the  "Collateral  Agent") and the other Credit
Parties signatory hereto (the "Credit Parties").

                              W I T N E S S E T H:

              WHEREAS,  the Borrower,  Holdco,  the Arrangers,  the  Syndication
Agent, the Administrative Agent, the Collateral Agent and the Credit Parties are
parties to that certain Credit  Agreement dated as of April 20, 1999, as amended
by that certain First Amendment to Credit Agreement dated as of August 23, 1999,
as further amended by that certain Second Amendment to Credit Agreement dated as
of December 22, 1999,  as further  amended by that  certain  Third  Amendment to
Credit  Agreement  dated as of  February  14,  2000 (as the same may be  further
amended,  restated,  supplemented  or otherwise  modified from time to time, the
ACredit Agreement@); and

              WHEREAS,   the  Borrower  and  Holdco  have  requested,   and  the
Arrangers, the Syndication Agent, the Administrative Agent, the Collateral Agent
and the Credit Parties have agreed,  to amend the Credit Agreement as and to the
extent set forth herein;

              NOW THEREFORE,  in  consideration of the premises set forth above,
the  terms  and  conditions   contained  herein  and  other  good  and  valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties  hereby  agree that all  capitalized  terms used  herein  shall have the
meanings ascribed thereto in the Credit Agreement,  as amended hereby, except as
otherwise  defined  or  limited  herein,  and  further  agree,  subject  to  the
conditions precedent to this Amendment hereinafter set forth, as follows:

              1.      Amendments to Article 1.

                      (a)      Article 1 of the Credit Agreement, Definitions,
is hereby modified and amended by adding the following new definitions to be
placed in appropriate alphabetical order:


                      "Additional  Telecorp Towers" shall mean up to 250 Towers
              (such  number  being  subject to  increase  or  decrease  based on
              negotiations  between the Borrower and Telecorp) to be constructed
              or  acquired  by the  Borrower,  from  time to time,  for lease

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              to Telecorp  pursuant to the future tower commitment set forth in
              the Telecorp Purchase Documents.

                      "Fourth  Amendment"  shall mean the Fourth  Amendment  to
              this Agreement dated as of March ___, 2000.

                      "Holdco  2010  Notes"  shall  mean  shall mean the Senior
              Notes and the Senior  Discount Notes, in each case due 2010 issued
              by Holdco  pursuant to the terms and  conditions  of the Indenture
              For 2010 Notes.

                      "Holdco Equity Offering" shall mean the issuance and sale
              by Holdco of  25,645,000  shares of its common  Capital Stock that
              was consummated on or about February 1, 2000.

                     "Indenture For 2010 Notes" shall mean, collectively, that
              certain  Senior Notes  Indenture to be entered into by Holdco,  as
              issuer,  and United  States Trust Company of New York, as trustee,
              in respect of the  Holdco  2010  Notes,  and that  certain  Senior
              Discount Notes Indenture to be entered into by Holdco,  as issuer,
              and United  States  Trust  Company  of New York,  as  trustee,  in
              respect of the Holdco 2010 Notes,  which Indentures shall provide,
              among other things,  that (a) interest  payable on the Holdco 2010
              Notes may be paid at a coupon no greater than, (i) with respect to
              the  Senior  Notes,  12.5%,  and (ii) with  respect  to the Senior
              Discount  Notes,  14.5%,  (b)  interest  shall not be payable with
              respect to more than  $200,000,000  of the Holdco 2010 Notes prior
              to the  expiration  of the Five  Year  PIK  Period  except  from a
              Pre-Funded  Interest Account,  and (c) the Holdco 2010 Notes shall
              have no required cash redemptions  (other than customary change of
              control  redemption  provisions) or principal  maturities prior to
              the Tranche B Maturity Date.

                      "Target  Acquisition" shall mean that certain Acquisition
              of Tower Assets in conjunction  with up to 110 Tower Sites,  which
              shall be  consummated  by the  Borrower  on terms  and  conditions
              reasonably  satisfactory  to  the  Administrative  Agent,  for  an
              aggregate Purchase Price not to exceed $180,000,000.

                    "Telecorp"  shall mean Telecorp PCS,  Inc., a [_________]
              corporation.

                      "Telecorp  Acquisition" shall mean the Acquisition by the
              Borrower  of  certain   Tower  Assets  from   Telecorp   including
              approximately  205 Tower Sites for an aggregate  Purchase Price of
              approximately  $61,500,000,  and the  related  lease to  Telecorp,
              under a master lease  agreement,  of space on such Towers (and any
              Additional  Telecorp  Towers) and ground  space on the land in the
              vicinity  of such  Towers (and any  Additional  Telecorp  Towers),
              pursuant  to the terms and  conditions  of the  Telecorp  Purchase
              Documents.

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                      "Telecorp  Purchase  Documents"  shall mean the documents
              relating to the Telecorp  Acquisition,  which shall  contain terms
              and  conditions  reasonably  satisfactory  to  the  Administrative
              Agent,  as such  documents  may be  amended  from  time  to  time,
              together  with  all  schedules  and  exhibits  thereto  and  other
              documents executed in connection therewith.

                      "UK Investment" shall mean the Investment  (including the
              purchase of  approximately  fifty  percent (50%) of the issued and
              outstanding  equity  interests  in such joint  venture) by Holdco,
              directly  or  indirectly,  in  a  joint  venture  with  an  entity
              organized under the laws of the United Kingdom and having a market
              capitalization  in excess of  $5,000,000,000,  for the  purpose of
              engaging   in  the   business   of  owning,   leasing,   managing,
              Abuilding-out@  and constructing  Towers in the United Kingdom and
              Europe, in an aggregate amount not to exceed,  (a) with respect to
              stock  consideration,  $100,000,000  in  common  Capital  Stock of
              Holdco  (or  assets  of Holdco  acquired  in  connection  with the
              issuance  of such  Capital  Stock),  and (b) with  respect to cash
              consideration, $100,000,000 in cash.

                      "UK  Acquisition  Documents"  shall  mean  the  documents
              relating to the UK  Investment,  as amended from time to time, and
              all schedules and exhibits thereto and other documents executed in
              connection therewith."

                      (b)      Article 1 of the Credit Agreement, Definitions,
is hereby further modified and amended by deleting the existing definition of
AIndentures@ and by substituting the following in lieu thereof:

                      "Indentures" shall mean, collectively,  the Indenture For
              2008 Notes,  the  Indenture  For 2009 Notes and the  Indenture For
              2010 Notes."

                      (c)      Article 1 of the Credit Agreement, Definitions,
is hereby further modified and amended by deleting the existing definition of
APre-Approved Transactions@ and by substituting the following in lieu thereof:

                      "Pre-Approved Transactions= shall mean, collectively, the
              Apex   Acquisition,   the  DigiPH   Acquisition,   the   UbiquiTel
              Investment,  the  AirTouch  Acquisition,  the UK  Investment,  the
              Nextel  2   Acquisition,   the   Telecorp   Acquisition   and  the
              Acquisitions described in Sections 8.5(xiii) and (xv) hereof."

                      (d)      Article 1 of the Credit Agreement, Definitions,
is hereby further modified and amended by deleting the existing definition of
"Pre-Approved Transaction Documents" and by substituting the following in lieu
thereof:


                      "Pre-Approved    Transaction   Documents=   shall   mean,
              collectively,  the Westower Merger  Agreement,  the NTA Investment
              Documents,  the Apex  Acquisition  Documents,  the DigiPH Purchase
              Documents,   the  UbiquiTel  Investment  Documents,

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              the  AirTouch Purchase Documents, the Nextel 2 Purchase
              Documents, UK Investment Documents, the Telecorp Purchase
              Documents, the documents relating to the  acquisition of
              Additional  Nextel Towers and the documents relating to the
              Acquisitions  described in Section  8.5(xiii) and (xv) hereof
             (including all schedules and exhibits thereto)."

                      (e)      Article 1 of the Credit Agreement, Definitions,
is hereby further modified and amended by adding the following sentence at the
end of the existing definition of "Subsidiary":

                      "Notwithstanding  anything  contained in the  foregoing to
              the contrary,  neither the UK Investment nor any entity formed for
              the purpose of making the UK Investment that is owned, directly or
              indirectly,  by Holdco shall be deemed a  Subsidiary  of Holdco or
              the Borrower for purposes of this Agreement."

              2. Amendment to Section 2.7. Section 2.7 of the Credit  Agreement,
Mandatory   Repayments,   is  hereby   modified  and  amended  by  deleting  the
parenthetical beginning in the second line of subsection (c) and by substituting
the following in lieu thereof:

                      "(other  than the  issuance of the Holdco 2009 Notes in an
              amount not to exceed  $340,003,656  and the issuance of the Holdco
              2010 Notes in an amount not to exceed $500,000,000)"

              3.  Amendment  to  Section  5.1.  Section  5.1(h)  of  the  Credit
Agreement,  Title to Assets, is hereby modified and amended by deleting the last
sentence therefrom and by substituting the following in lieu thereof:

              "Tower  Sub does not own any  material  Assets  other  than  Tower
              Assets  comprising  the Nextel  Collateral  and Tower  Space Lease
              Agreements  with  Co-Locators  on  Towers  comprising  the  Nextel
              Collateral, and Holdco does not own any material Assets other than
              (i) the Capital Stock of the Borrower,  (ii) the UK Investment (or
              the Capital  Stock of any entity  formed for the purpose of making
              the  UK  Investment),   (iii)  the  Capital  Stock  of  any  shell
              Subsidiary formed by Holdco solely for the purpose of consummating
              any  Permitted  Acquisition,  and (iv) on the closing  date of any
              Permitted  Acquisition,  the Capital  Stock of any target  company
              acquired in connection with such Permitted Acquisition immediately
              prior to the contribution of such Capital Stock to the Borrower."

              4. Amendment to Section 6.2. Section 6.2 of the Credit  Agreement,
Business;  Compliance  with  Applicable  Law, is hereby  amended by deleting the
second sentence therefrom and substituting the following in lieu thereof:


                      "Holdco will engage  solely in the business of holding the
              Capital Stock of (a) the Borrower,  (b) the UK Investment  (or the
              Capital  Stock of any entity  formed for

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              the purpose of making the UK Investment),  (c) any shell
              Subsidiary  formed by Holdco solely for the purpose of
              consummating any Permitted Acquisition, and (d) on the  closing
              date of any  Permitted  Acquisition,  any  target company
              acquired in connection  with such  Permitted  Acquisition
              immediately prior to the contribution of such Capital Stock to the
              Borrower."

              5. Amendments to Section 6.16.

                      (a)      Section 6.16 of the Credit Agreement, Covenants
Regarding Formation of Subsidiaries and the Making of Investments  and
Acquisitions,  is hereby  modified and amended by deleting the parenthetical
beginning  after the words Asuch  Subsidiary or Person@ in clause (b) of the
first sentence and by substituting the following in lieu thereof:

              "(other than (i) the Foreign Westower Subsidiaries,  in which case
              the pledge shall be of sixty-five percent (65%) (or in the case of
              Westower Highlight Do Brazil,  sixty percent (60%)) of the Capital
              Stock  of such  Subsidiary  and  (ii)  the UK  Investment  (or the
              Capital  Stock of any entity  formed for the purpose of making the
              UK Investment))"

                      (b)  Section  6.16  of  the  Credit  Agreement,  Covenants
Regarding Formation of Subsidiaries and the Making of
Investments  and  Acquisitions,  is  hereby  further  modified  and  amended  by
inserting  A(other than the UK  Investment  (or the Capital  Stock of any entity
formed for the purpose of making the UK Investment))@  immediately following the
words Aafter the Agreement Date@ in the second sentence thereof.

              6.  Amendment  to  Article 6.  Article 6 of the Credit  Agreement,
Affirmative  Covenants,  is hereby  modified and amended by adding the following
new Section 6.17 at the end thereof:



                      "Section 6.17 Special Purpose Vehicles. The Borrower shall
              form one or more special purpose Subsidiaries (the ASPVs") for the
              purpose  of  holding  and  making  Acquisitions  of  Tower  Assets
              permitted  under Section 8.5 hereof,  and with respect to all such
              Acquisitions  completed on and after March ___, 2000, the Borrower
              shall, and shall cause each of its Subsidiaries to, contribute all
              Towers  and  Tower  Assets   acquired  by  the  Borrower  or  such
              Subsidiary to an SPV. The Borrower  shall comply with Section 6.16
              hereof in respect  of each SPV.  Notwithstanding  anything  to the
              contrary  contained in this  Agreement,  the following  provisions
              shall apply with respect to SPVs:  (a) any SPV may transfer  Tower
              Assets to Tower Sub to the  extent  that such Tower  Assets  shall
              constitute  Future  Nextel  Towers;  (b) none of the SPVs may make
              Investments  otherwise permitted to be made by Subsidiaries of the
              Borrower pursuant to Section 8.2 or 8.5(v) hereof; (c) none of the
              SPVs may liquidate or dissolve  itself (or suffer any  liquidation
              or dissolution),  or enter into any merger, consolidation or other
              business   combination   (except  with  another  SPV),   otherwise
              permitted to be made by Subsidiaries  of the Borrower  pursuant to
              Section
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              8.5(ii)   hereof;   (d)   none  of  the  SPVs  may  form
              Subsidiaries;   (e)  SPVs  may  transfer   Assets  freely  amongst
              themselves, but not to the Borrower or any other Subsidiary of the
              Borrower  that does not  constitute  an SPV;  (f) none of the SPVs
              shall create,  assume, incur or remain obligated in respect of, or
              permit to be  outstanding,  any  Indebtedness  except for trade or
              accounts  payable and other  obligations,  and  accrued  expenses,
              incurred  in the  ordinary  course  of  business,  other  than for
              borrowed  money;  and (g) none of the SPVs shall be  obligated  in
              respect of any  Guaranty  of the  performance  obligations  of the
              Borrower  or any of its  Subsidiaries  (other  than under the Loan
              Documents).  Neither Tower Sub nor  California Sub shall be deemed
              SPVs for purposes of this Agreement."

              7. Amendments to Section 8.1.

                      (a)    Section 8.1 of the Credit Agreement, Indebtedness,
is hereby modified and amended by deleting clause (i) from subsection (h) and by
substituting the following in lieu thereof:

              "(i) Indebtedness represented by the Holdco 2008 Notes, the Holdco
2009 Notes and the Holdco 2010 Notes,"

                      (b) Section 8.1 of the Credit Agreement,  Indebtedness, is
hereby further modified and amended by deleting
clause (iii) from subsection (h) and by substituting the following in lieu
thereof:

              "(iii) accrual of interest, accrual of dividends, the accretion of
              accreted value,  the payment of interest in the form of additional
              Indebtedness   and  the  payment  of  dividends  in  the  form  of
              additional  shares in respect of the Holdco 2008 Notes, the Holdco
              2009  Notes,   the  Holdco  2010  Notes  or  any  other  Permitted
              High-Yield Securities,"

                      (c) Section 8.1 of the Credit Agreement,  Indebtedness, is
hereby further modified and amended by deleting
the phrase Aeither of the Indentures"  from clause (iv) of subsection (h) and by
substituting Aany of the Indentures" in lieu thereof.

              8. Amendments to Section 8.5.

                      (a) Section 8.5 of the Credit Agreement, Liquidation;
Merger; Acquisition or Disposition of Assets, is hereby modified and amended by
deleting  existing  subsection  (xii) thereof and substituting the following in
lieu thereof:


                      "(xii)  so long as no  Default  or Event of  Default  then
              exists or would be caused  thereby,  subject  to  compliance  with
              Sections   6.10  and  6.16  hereof,   (A)  the  Borrower  and  its
              Subsidiaries  (other  than  Tower Sub and  California  Tower)  may
              consummate each of the Pre-Approved  Transactions  (other than the
              Nextel  2
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              Acquisition,  the UK  Investment  and  the  transaction described
              in  clause  (xiii)  below),  and (B) the  Borrower  may construct
              or purchase the Additional  Telecorp  Towers;  provided,  however,
              that  with  respect  to the  Telecorp  Acquisition,  the Borrower
              shall provide the Arrangers with evidence satisfactory to them
              that  Holdco  shall have  received at least  $400,000,000  of
              proceeds in connection with the issuance of the 2010 Notes (or, in
              the   alternative,   provide   the   Arrangers   and  the  Lenders
              calculations demonstrating pro forma compliance with the Financial
              Covenants after giving effect to the Telecorp Acquisition)."

                      (b)   Section 8.5 of the Credit Agreement, Liquidation;
Merger; Acquisition or Disposition of Assets, is hereby  further  modified and
amended by adding the  following  new  subsections (xiv) and (xv) at the end
thereof:

                      "(xiv)  so long as no  Default  or Event of  Default  then
              exists or would be caused thereby, and notwithstanding anything to
              the contrary contained herein or in any Loan Document, Holdco may,
              directly or indirectly,  make and hold the UK Investment,  so long
              as the cash portion of the Purchase Price is from the Net Proceeds
              received by Holdco in  connection  with the issuance of the Holdco
              2010 Notes or the Holdco Equity Offering; and

                      "(xv) so long as (A) no Default  or Event of Default  then
              exists or would be caused thereby,  (B) the Borrower shall provide
              the Arrangers with evidence satisfactory to them that Holdco shall
              have received at least $400,000,000 of proceeds in connection with
              the  issuance of the 2010 Notes (or, in the  alternative,  provide
              the Arrangers and the Lenders calculations demonstrating pro forma
              compliance  with the  Financial  Covenants  after giving effect to
              such  Acquisition),   and  (C)  the  Borrower  shall  provide  the
              Administrative  Agent with  evidence  satisfactory  to it that the
              revenue and cash flow acquired by the Borrower in connection  with
              the Target Acquisition shall have no material negative  deviations
              from the  projected  revenue and cash flow  relating to the Target
              Acquisition as set forth in the Borrower=s  Projections  delivered
              to  the  Administrative   Agent  in  connection  with  the  Fourth
              Amendment,  the Borrower may,  subject to compliance with Sections
              6.10, 6.16 and 6.17 hereof, consummate the Target Acquisition."

              9. Amendments to Section 8.7.

                      (a)      Section 8.7 of the Credit Agreement, Restricted
Payments and Purchases, is hereby modified and amended by deleting clause (a)
and by substituting the following in lieu thereof:


             "(a) (i)  interest  payments  on the Holdco  2008 Notes and on the
              Holdco  2009  Notes,  (ii)  interest  payments  on the Holdco 2010
              Notes, and (iii) interest or dividend payments, as applicable,  on
              Permitted High-Yield  Securities issued on or before the

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              Agreement Date, in the case of clauses (i) and (iii),  following
              expiration of  the  Five  Year  PIK  Period  or  from a
              Pre-Funded  Interest Account,"

                      (b)  Section  8.7  of  the  Credit  Agreement,  Restricted
Payments and Purchases, is hereby further modified and
amended by deleting clause (e) and by substituting the following in lieu thereof

           "(e) payments of >Additional Interest= (as that term is defined in
              the Registration Rights Agreements entered into in connection with
              the Holdco 2008  Notes,  the Holdco 2009 Notes and the Holdco 2010
              Notes)  and any other  comparable  payments  in  respect  of other
              Permitted High-Yield Securities"

              10. Amendment to Section 8.9. Section 8.9 of the Credit Agreement,
Corporate Name;  Corporate  Structure;  Business,  is hereby amended by deleting
subsection (b) therefrom and by substituting the following in lieu thereof:

                      "(b) with respect to the  Borrower  and its  Subsidiaries,
              engage in any businesses  other than the Tower  Operations and the
              Other Operations and activities  related or incident thereto,  and
              with respect to Holdco,  engage in any business other than that of
              holding  the  Capital  Stock  of (i)  the  Borrower,  (ii)  the UK
              Investment  (or the  Capital  Stock of any  entity  formed for the
              purpose of making the UK Investment),  (iii) any shell  Subsidiary
              formed  by Holdco  solely  for the  purpose  of  consummating  any
              Permitted  Acquisition,  and  (iv)  on  the  closing  date  of any
              Permitted  Acquisition,  any target company acquired in connection
              with  such  Permitted   Acquisition   immediately   prior  to  the
              contribution of such Capital Stock to the Borrower"

              11.  Amendment  to  Section  10.1.  Section  10.1  of  the  Credit
Agreement,  Events of  Default  (Senior  Obligations),  is hereby  modified  and
amended by deleting the phrase Aeither of the  Indentures"  from  subsection (m)
and by substituting Aany of the Indentures@ in lieu thereof.

              12. No Other  Amendments,  Waivers  or  Consents.  Except  for the
amendments,  waivers  and  consents  set  forth  above,  the text of the  Credit
Agreement and the other Loan Documents shall remain  unchanged and in full force
and effect, and the Arrangers,  the Syndication Agent, the Administrative Agent,
the Collateral  Agent and the Credit Parties hereby reserve the right to require
strict  compliance  with the terms of the  Credit  Agreement  and the other Loan
Documents in the future.

              13. Conditions to Effectiveness. This Amendment shall be effective
as of the date first written above (the AEffective Date@) upon the following:

                      (a)      The Administrative Agent=s receipt of a
counterpart hereof duly executed by the Borrower and Holdco, and by the Majority
Lenders;
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                      (b) With respect to issuance of the Holdco 2010 Notes, the
              Arrangers" receipt of calculations  demonstrating  the Borrower=s
              pro forma compliance with the Credit Agreement through the Tranche
              B Maturity Date; and

                      (c) All of the  representations  and  warranties of Holdco
              and the  Borrower  set  forth  in the  Credit  Agreement  and this
              Amendment,  other  than  those  that  are  expressly  made as of a
              specific date, are true and correct in all material  respects with
              the same effect as though such  representations and warranties had
              been made on and as of the Effective Date as though made on and as
              of such date.

              14.  Amendment  Fee.  The  Borrower  hereby  agrees to pay, on the
Effective  Date, to each Lender that delivers such Lender=s  written  consent to
this Amendment to counsel for the  Administrative  Agent prior to 5:00 p.m. (New
York time) on Thursday,  March 9, 2000,  an amendment  fee in an amount equal to
one-tenth of one percent (0.10%) of such Lender=s Revolving  Commitment and Term
Loans then outstanding.

              15.  Conditions  Subsequent.  As a  condition  subsequent  to  the
amendments set forth in this  Amendment,  the Borrower shall perform or cause to
be performed the  following  (the failure by the Borrower to so perform or cause
to be performed for any reason constituting an Event of Default under the Credit
Agreement):

                      (a)  Collateral.  Promptly  following the closing date for
              each of the Telecorp  Acquisition and the Target Acquisition,  the
              Borrower  shall  execute and deliver to the  Collateral  Agent all
              agreements,   instruments  and  other  items  required  to  be  so
              delivered  pursuant  to  Section  6.16  of the  Credit  Agreement,
              including,  without  limitation,  a collateral  assignment  of the
              Telecorp Purchase Documents in favor of the Collateral Agent; and

                      (b) Definitive Documentation. Promptly upon the closing of
              each of the Telecorp  Acquisition and the Target Acquisition,  the
              Borrower  shall  deliver to the  Arrangers a full set of copies of
              the documents  executed in connection with each such  Acquisition.
              Promptly upon  consummation  of the  transactions  contemplated in
              connection  with  the  issuance  of the  Holdco  2010  Notes,  the
              Borrower  shall  deliver to the  Arrangers a full set of copies of
              the  Indenture  For 2010  Notes,  the  Holdco  2010  Notes and all
              documents executed in connection therewith.

              16.  Representations  and  Warranties.  Each of the  Borrower  and
Holdco, for itself and on behalf of each of its Subsidiaries, agrees, represents
and  warrants  in  favor  of  the  Arrangers,   the   Syndication   Agent,   the
Administrative Agent, the Collateral Agent and the Credit Parties that:



                      (a) This Amendment has been executed and delivered by duly
              authorized  representatives  of the Borrower  and Holdco,  and the
              Credit  Agreement,  as  modified  and  amended by this  Amendment,
              constitutes a legal,  valid and binding obligation of

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              the Borrower and Holdco and is  enforceable  against the Borrower
              and Holdco in accordance with its terms, except as enforceability
              may be limited by  bankruptcy,   insolvency,   reorganization   or
              similar  laws affecting  creditors'  rights  generally and by the
              application of general equitable principles;

                      (b) Before and after giving effect to this  Amendment,  no
              Default or Event of Default with respect to the Borrower or Holdco
              has occurred and is continuing;

                      (c) As of the date hereof and after  giving  effect to the
              issuance  of the  Holdco  2010  Notes,  (i)  the  property  of the
              Borrower,  at a fair  valuation  on a going  concern  basis,  will
              exceed  its debt;  (ii) the  capital of the  Borrower  will not be
              unreasonably small to conduct its business; and (iii) the Borrower
              will not have  incurred  debts,  or have  intended to incur debts,
              beyond its ability to pay such debts as they mature; and

                      (d) No event  contemplated in connection with the issuance
              of the Holdco 2010 Notes shall occur, which has not been consented
              to or waived,  the  occurrence of which  constitutes,  or with the
              passage  of time or giving of notice or both would  constitute,  a
              material  default  by  Holdco,   the  Borrower  or  any  of  their
              respective Subsidiaries under any material indenture, agreement or
              other  instrument,  including,  without  limitation,  the material
              Necessary  Authorizations  and the  Indentures,  or any  judgment,
              decree or order,  to which  Holdco,  the  Borrower or any of their
              respective  Subsidiaries  is a  party  or  by  which  Holdco,  the
              Borrower or any of their  respective  Subsidiaries or any of their
              respective properties may be bound or affected.

              17.  Effect  on  the  Credit  Agreement.  Except  as  specifically
provided herein, the Credit Agreement shall remain in full force and effect, and
is hereby ratified,  reaffirmed and confirmed. This Amendment shall be deemed to
be a Loan Document for all purposes.

              18. Counterparts.  This Amendment may be executed in any number of
separate   counterparts  and  by  the  different   parties  hereto  on  separate
counterparts,  each of which shall be deemed an original and all of which, taken
together, shall be deemed to constitute one and the same instrument.  In proving
this Amendment in any judicial proceedings, it shall not be necessary to produce
or account for more than one such  counterpart  signed by the party against whom
such  enforcement is sought.  Any  signatures  delivered by a party by facsimile
transmission shall be deemed an original signature hereto.



              19. Law of Contract. THIS CONSENT SHALL BE CONSTRUED IN ACCORDANCE
WITH AND GOVERNED BY THE INTERNAL  LAWS OF THE STATE OF NEW YORK  APPLICABLE  TO
CONTRACTS MADE AND TO BE PERFORMED WHOLLY WITHIN SUCH STATE.



                [REMAINDER OF THIS PAGE INTENTIONALLY LEFT BLANK]

                                       10



<PAGE>   11





                      IN WITNESS WHEREOF,  this Amendment has been duly executed
as of the day and year first written above.

BORROWER:                      SPECTRASITE COMMUNICATIONS, INC.


                                        By:      /s/ David P. Tomick
                                           -----------------------------------
                                        Name:         David P. Tomick
                                             ---------------------------------
                                        Title:        Executive Vice President
                                              --------------------------------


                                    Attest:
                                             --------------------------------
                                     Name:
                                             --------------------------------
                                     Title:
                                             --------------------------------

HOLDCO:                        SPECTRASITE HOLDINGS, INC.


                                        By:      /s/ David P. Tomick
                                             --------------------------------
                                        Name:         David P. Tomick
                                             --------------------------------
                                        Title:        Executive Vice President
                                             --------------------------------

                                    Attest:
                                             --------------------------------
                                     Name:
                                             --------------------------------
                                     Title:
                                             --------------------------------



<PAGE>   12



ADMINISTRATIVE                 CANADIAN IMPERIAL BANK OF
AGENT:                                  COMMERCE


                                        By:      /s/  Colleen Risorto
                                             --------------------------------
                                        Name:          Colleen Risorto
                                             --------------------------------
                                        Title:         Executive Director
                                             --------------------------------
                                             CIBC World Markets Corp. as Agent




<PAGE>   13



ARRANGERS:                               CIBC WORLD MARKETS CORP.
                                        (f/k/a CIBC Oppenheimer Corp.)

                                        By:      /s/  Colleen Risorto
                                             --------------------------------
                                        Name:          Colleen Risorto
                                             --------------------------------
                                        Title:         Executive Director
                                             --------------------------------
                                             CIBC World Markets Corp. as Agent


                                        CREDIT SUISSE FIRST BOSTON


                                        By:      /s/  James P. Moran
                                             --------------------------------
                                        Name:          James P. Moran
                                             --------------------------------
                                        Title:              Director

                                        By:      /s/  Kristin Lepri
                                             --------------------------------
                                        Name:          Kristin Lepri
                                             --------------------------------
                                        Title:         Associate
                                             --------------------------------




<PAGE>   14



COLLATERAL AGENT:     CANADIAN IMPERIAL BANK OF COMMERCE


                                        By:      /s/  Colleen Risorto
                                             --------------------------------
                                        Name:          Colleen Risorto
                                             --------------------------------
                                        Title:         Executive Director
                                             --------------------------------
                                             CIBC World Markets Corp. as Agent




<PAGE>   15



SYNDICATION AGENT:    CREDIT SUISSE FIRST BOSTON


                                        By:      /s/  James P. Moran
                                             --------------------------------
                                        Name:          James P. Moran
                                             --------------------------------
                                        Title:              Director
                                             --------------------------------


                                        By:      /s/  Kristin Lepri
                                             --------------------------------
                                        Name:          Kristin Lepri
                                             --------------------------------
                                        Title:         Associate
                                             --------------------------------



<PAGE>   16



MANAGING AGENTS:               BANK OF MONTREAL, CHICAGO BRANCH


                                        By:      /s/  Karen Klapper
                                             --------------------------------
                                        Name:          Karen Klapper
                                             --------------------------------
                                        Title:         Director
                                             --------------------------------


                                        THE BANK OF NOVA SCOTIA

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

                                   FLEET NATIONAL BANK (f/k/a BankBoston, N.A.)


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

                                   DRESDNER BANK AG, NEW YORK AND GRAND
                                   CAYMAN BRANCHES


                                        By:      /s/  Patrick A. Kelehe
                                             --------------------------------
                                        Name:       Patrick A. Kelehe
                                             --------------------------------
                                        Title:         Vice President
                                             --------------------------------

                                        By:      /s/  Brian E. Haughne
                                             --------------------------------
                                        Name:       Brian E. Haughney
                                             --------------------------------
                                        Title:         Assistant Vice President
                                             --------------------------------

                                        TORONTO DOMINION (TEXAS), INC.

                                        By:      /s/  Ann Slanis
                                             --------------------------------
                                        Name:          Ann Slanis
                                             --------------------------------
                                        Title:          Vice President
                                             --------------------------------



<PAGE>   17



                                        UNION BANK OF CALIFORNIA, N.A.


                                        By:      /s/  Peter C. Connoy
                                             --------------------------------
                                        Name:       Peter C. Connoy
                                             --------------------------------
                                        Title:         Vice President
                                             --------------------------------


<PAGE>   18



CO-AGENT:                      CREDIT LYONNAIS NEW YORK BRANCH


                                        By:      /s/  Patrick McCarthy
                                             --------------------------------
                                        Name:          Patrick McCarthy
                                             --------------------------------
                                        Title:         Authorized Signature
                                             --------------------------------


<PAGE>   19



LENDERS:                       CIBC INC.


                                        By:      /s/  Colleen Risorto
                                             --------------------------------
                                        Name:          Colleen Risorto
                                             --------------------------------
                                        Title:           Executive Director
                                             --------------------------------
                                             CIBC World Markets Corp. as Agent





<PAGE>   20



                                        CREDIT SUISSE FIRST BOSTON


                                        By:      /s/ James P. Moran
                                             --------------------------------
                                        Name:         James P. Moran
                                             --------------------------------
                                        Title:             Director
                                             --------------------------------


                                        By:      /s/  Kristin Lepri
                                             --------------------------------
                                        Name:          Kristin Lepri
                                             --------------------------------
                                        Title:
                                             --------------------------------




<PAGE>   21



                                        BANK OF MONTREAL, CHICAGO BRANCH


                                        By:      /s/  Karen Klapper
                                             --------------------------------
                                        Name:          Karen Klapper
                                             --------------------------------
                                        Title:             Director
                                             --------------------------------



<PAGE>   22



                                        THE BANK OF NOVA SCOTIA


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



<PAGE>   23



                                    FLEET NATIONAL BANK (f/k/a BankBoston, N.A.)


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

<PAGE>   24



              DRESDNER BANK AG, NEW YORK AND GRAND CAYMAN BRANCHES


                                        By:      /s/  Patrick A. Keleher
                                             --------------------------------
                                        Name:          Patrick A. Keleher
                                             --------------------------------
                                        Title:            Vice President
                                               --------------------------------


                                        By:      /s/  Brian E. Haughney
                                             --------------------------------
                                        Name:          Brian E. Haughney
                                             --------------------------------
                                        Title:         Assistant Vice President
                                                 -------------------------------



<PAGE>   25



                                        TORONTO DOMINION (TEXAS), INC.


                                        By:      /s/  Ann S. Slanis
                                             --------------------------------
                                        Name:          Ann S. Slanis
                                             --------------------------------
                                        Title:            Vice President
                                               --------------------------------




<PAGE>   26



                                        UNION BANK OF CALIFORNIA, N.A.


                                        By:      /s/  Peter C. Connoy
                                             --------------------------------
                                        Name:          Peter C. Connoy
                                             --------------------------------
                                        Title:               Vice President
                                             --------------------------------




<PAGE>   27



                                        CREDIT LYONNAIS NEW YORK BRANCH


                                        By:      /s/  Patrick McCarthy
                                             --------------------------------
                                        Name:          Patrick McCarthy
                                             --------------------------------
                                        Title:           Authorized Signature
                                             --------------------------------




<PAGE>   28



                                        THE BANK OF NEW YORK


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



<PAGE>   29



                                        CAISSE DE DEPOT ET PLACEMENT DU QUEBEC


                                        By:      /s/  Louie Lavoie
                                             --------------------------------
                                        Name:          Louie Lavoie
                                             --------------------------------
                                        Title:              Manager
                                             --------------------------------


                                        By:      /s/  Lucie Rousseau
                                             --------------------------------
                                        Name:          Lucie Rousseau
                                               --------------------------------
                                        Title:                  Vice President
                                               --------------------------------


<PAGE>   30



                                        CANADIAN IMPERIAL BANK OF COMMERCE


                                        By:      /s/  Colleen Risorto
                                             --------------------------------
                                        Name:          Colleen Risorto
                                             --------------------------------
                                        Title:           Executive Director
                                             --------------------------------
                                              CIBC World Markets Corp. as Agent



<PAGE>   31



                                        THE CIT GROUP/EQUIPMENT FINANCING, INC.


                                        By:      /s/  Daniel E. A. Nichols
                                             --------------------------------
                                        Name:          Daniel E. A. Nichols
                                             --------------------------------
                                        Title          Assistant Vice President
                                             --------------------------------




<PAGE>   32



                                        CYPRESSTREE INVESTMENT FUND, LLC

                                        By:      CypressTree Investment
                                                 Management Company, Inc., its
                                                 Managing Member


                                        By:      /s/  Peter K. Merrill
                                             --------------------------------
                                        Name:          Peter K. Merrill
                                             --------------------------------
                                        Title:              Managing Director
                                             --------------------------------




<PAGE>   33



                                        NORTHAMERICAN SENIOR FLOATING RATE FUND

                                        By:      CypressTree Investment
                                                 Management Company, Inc., its
                                                 Managing Member


                                        By:      /s/  Peter K. Merrill
                                             --------------------------------
                                        Name:          Peter K. Merrill
                                             --------------------------------
                                        Title:              Managing Director
                                             --------------------------------


<PAGE>   34



                                CYPRESSTREE INVESTMENT MANAGEMENT COMPANY, INC.

                                        As:      Attorney-in-Fact and on behalf
                                                 of First Allmerica Financial
                                                 Life Insurance Company as
                                                 Portfolio Manager


                                        By:      /s/  Peter K. Merrill
                                             --------------------------------
                                        Name:          Peter K. Merrill
                                             --------------------------------
                                        Title:              Managing Director
                                             --------------------------------



<PAGE>   35



                                        KZH CYPRESSTREE-1 LLC


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



<PAGE>   36



                                        FREMONT INVESTMENT & LOAN


                                        By:      /s/  Kannika Viravan
                                             --------------------------------
                                        Name:       Kannika Viravan
                                             --------------------------------
                                        Title:         Vice President
                                             --------------------------------



<PAGE>   37



                                        HELLER FINANCIAL, INC.


                                        By:      /s/  Scott Ziemke
                                             --------------------------------
                                        Name:          Scott Ziemke
                                             --------------------------------
                                        Title:      Assistant Vice President
                                             --------------------------------



<PAGE>   38



                                        MERRILL LYNCH SENIOR FLOATING RATE FUND,
                                         INC.


                                        By:      /s/  Joseph Matteo
                                             --------------------------------
                                        Name:          Joseph Matteo
                                             --------------------------------
                                        Title:
                                             --------------------------------



<PAGE>   39



                                        PPM AMERICA, INC., as attorney in fact,
                                        on behalf of Jackson National Life
                                        Insurance Company


                                        By:      /s/  John Walding
                                             --------------------------------
                                        Name:          John Walding
                                             --------------------------------
                                        Title:             Managing Director
                                             --------------------------------



<PAGE>   40



                                        Fleet  National Bank (f/k/a  BankBoston,
                                        N.A.),   as  Trust   Administrator   for
                                        LONGLANE MASTER TRUST IV


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



<PAGE>   41



                                        GALAXY CLO 1999-1, LTD.

                                        By:      SAI Investment Advisor, Inc.,
                                                 its Collateral Manager


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




<PAGE>   42



                                        OXFORD STRATEGIC INCOME FUND

                                        By:      Eaton Vance Management, as
                                                 Investment Advisor


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




<PAGE>   43



                                        SENIOR DEBT PORTFOLIO

                                        By:      Boston Management and Research,
                                                 as Investment Advisor


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




<PAGE>   44



                                        J.H. WHITNEY MARKET VALUE FUND, L.P.

                                        By:      J.H. Whitney Value GP, Ltd.,
                                                 its General Partner


                                        By:      /s/  Daniel J. O'Brien
                                             --------------------------------
                                        Name:       Daniel J. O'Brien
                                             --------------------------------
                                        Title:
                                             --------------------------------



<PAGE>   45



                                        J.H. WHITNEY MEZZANINE FUND, L.P.

                                  By:         Whitney GP, Ltd. - General Partner
                                               -------------------------------


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



<PAGE>   46



                                        BANK OF AMERICA, N.A.


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



<PAGE>   47



                                        DEBT STRATEGIES FUND I, INC.


                                        By:      /s/  Joseph Matte
                                             --------------------------------
                                        Name:          Joseph Matteo
                                             --------------------------------
                                        Title:
                                             --------------------------------




<PAGE>   48



                                        DEBT STRATEGIES FUND II, INC.


                                        By:      /s/  Joseph Matte
                                             --------------------------------
                                        Name:          Joseph Matteo
                                             --------------------------------
                                        Title:
                                             --------------------------------




<PAGE>   49



                                        THE FUJI BANK, LIMITED, NEW YORK BRANCH


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



<PAGE>   50



                                        VAN KAMPEN SENIOR INCOME TRUST


                                        By:      /s/  Darvin D. Pierce
                                             --------------------------------
                                        Name:       Darvin D. Pierce
                                             --------------------------------
                                        Title:         Vice President
                                             --------------------------------

<PAGE>   51



                                        PROSPECT INTERNATIONAL DEBT
                                        STRATEGY FUND


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





<PAGE>   52



                                        EATON VANCE SENIOR INCOME TRUST


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


<PAGE>   53



                                 MERRILL LYNCH SENIOR FLOATING RATE FUNDII, INC.


                                        By:      /s/  Joseph Matteo
                                             --------------------------------
                                        Name:          Joseph Matteo
                                             --------------------------------
                                        Title:
                                              --------------------------------




<PAGE>   54



                                   MORGAN STANLEY DEAN WITTER PRIME INCOME TRUST


                                        By:      /s/  Sheila Finnerty
                                             --------------------------------
                                        Name:       Sheila Finnerty
                                             --------------------------------
                                        Title:         Senior Vice President
                                             --------------------------------


<PAGE>   55



                                        SAWGRASS TRADING LLC


                                        By:      /s/  Kelly C. Walker
                                             ----------------------------
                                        Name:          Kelly C. Walker
                                             ----------------------------
                                        Title:               Vice President
                                             ----------------------------


<PAGE>   56



                                        BANC OF AMERICA SECURITIES LLC


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

<PAGE>   57



                                        FIRST DOMINION FUNDING III


                                        By:      /s/  Andrew H. Marshak
                                             ------------------------
                                        Name:       Andrew H. Marshak
                                             ------------------------
                                        Title:      Managing Director
                                             ------------------------