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                                                                     Exhibit 2.4



                       AMENDMENT TO AGREEMENT TO SUBLEASE


         This  Amendment to the  Agreement  to Sublease  (this  "Amendment")  is
entered   into  as  of  March  8,  2001   among   SpectraSite   Holdings,   Inc.
("SpectraSite"),  California Tower, Inc. ("TowerCo"), Verizon Wireless (VAW) LLC
(formerly  known as Vodafone  AirTouch  Licenses  LLC, as  successor to AirTouch
Communications,   Inc.)  ("AirTouch"),  Los  Angeles  SMSA  Limited  Partnership
("LASMSA"),   Oxnard-Ventura-Simi  Limited  Partnership  ("OVS")  (collectively,
AirTouch, LASMSA and OVS referred to herein as the "Sublessors"),

                                   WITNESSETH:

         WHEREAS, the parties hereto entered into an Agreement to Sublease dated
February 16, 2000 (the  "Agreement to Sublease"),  pursuant to which  Sublessors
agreed to lease or sublease certain cellular towers to TowerCo;

         WHEREAS,  pursuant to the Agreement to Sublease,  the Final Closing was
to occur no later than February 15, 2001;

         WHEREAS,  pursuant to a letter agreement dated as of February 15, 2001,
the parties agreed to negotiate in good faith for a three week period to explore
whether the parties desired to extend the date upon which the Final Closing must
occur;

         WHEREAS,  the parties now mutually desire to extend the date upon which
the Final Closing must occur to June 29, 2001 under the terms and conditions set
forth in this Amendment; and

         WHEREAS, in order to effectuate these purposes, the parties hereto have
entered into this Amendment.

         NOW, THEREFORE, for and in consideration of valuable consideration, the
receipt  and  sufficiency  of which are  hereby  acknowledged,  and  further  in
consideration  of the mutual  covenants and  agreements  contained  herein,  the
parties agree as follows:

     1.  Section  1.19 of the  Agreement  to  Sublease  shall be  deleted in its
entirety and replaced with the following:

                  Included Towers.  Means:

                    a.   all Towers  included within a Closing which occurred on
                         or before February 15, 2001;

                    b.   the Tower at the Site  designated on Annex I as PV-386;
                         and

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                    c.   those  Towers  included on Annex I hereto (i) which are
                         not  included in  subsection  1(a) above and (ii) which
                         TowerCo, in its sole discretion, consents to in writing
                         to   be   included   within   a   Closing;    including
                         modifications of terms as the parties may agree.


     2. The third  sentence of Section 2.2(b) of the Agreement to Sublease shall
be deleted in its entirety and replaced with the following:

                  If such  consent is obtained  prior to the Final  Closing Date
                  with respect to any Restricted Item, such item and the related
                  Tower and other  associated  Assets  shall be subjected to the
                  Sublease at the next practicable Subsequent Closing; provided,
                  however,  that Towers and other associated Assets not included
                  within a Closing which occurred on or before February 15, 2001
                  (except the Tower at the Site designated on Annex I as PV-386)
                  must  also  be  consented  to in  writing  prior  to the  next
                  Subsequent  Closing by TowerCo in order to be subjected to the
                  Sublease as provided in Section 1.19(c) herein.

     3. The first  sentence of the first  paragraph  of  Schedule  2.2(b) of the
Agreement to Sublease  shall be deleted in its  entirety  and replaced  with the
following:

          For  Towers  included  within a Closing  which  occurred  on or before
          February 15, 2001:

                           From the Initial  Closing Date  through  February 15,
                           2001, TowerCo shall use its best efforts on behalf of
                           Sublessors  to  obtain  the  consent   referenced  in
                           Section  2.2 of the  Agreement  to subject  any given
                           Restricted Item to the Sublease.

     4. The following is hereby  inserted  after the last  paragraph of Schedule
2.2(b) of the Agreement to Sublease:

          For Towers not included  within a Closing which  occurred on or before
          February 15, 2001 the two paragraphs above shall not apply and instead
          the following three paragraphs shall apply in lieu thereof:

                           After  March 8, 2001  until the Final  Closing  Date,
                           TowerCo  shall use  reasonable  efforts  on behalf of
                           Sublessors  to  obtain  the  consents  referenced  in
                           Section 2.2 of the  Agreement to  Sublease;  provided
                           that TowerCo  shall have (i) the option of requesting
                           from the ground lessor consent to sublease  Available
                           Space  (as   defined  in  the   Sublease)   to  Space

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                           Subtenants  (as defined in the  Sublease) at the same
                           time that it requests consent on behalf of Sublessors
                           to  sublease a  Restricted  Item to TowerCo  and (ii)
                           discretion as to the amount of a one-time payment, if
                           any,  to offer to the  applicable  ground  lessor  in
                           order to obtain the consent to sublease a  Restricted
                           Item to TowerCo and to sublease  Available  Space (as
                           defined  in the  Sublease)  to Space  Subtenants  (as
                           defined in the  Sublease).  If a one-time  payment is
                           accepted  by the  applicable  ground  lessor  and the
                           applicable  Tower is an  Included  Tower  pursuant to
                           Section  1.19(c)  herein,  the  applicable  Sublessor
                           shall pay the  applicable  ground lessor an amount up
                           to $20,000 (per Tower) of any such one-time  payments
                           within 5 business days after the  applicable  Closing
                           on such  Tower  and  TowerCo  shall  pay such  ground
                           lessor any additional  amount  required in connection
                           with such consent.

                           TowerCo  shall  inform  Jason  Wilcox  (or such other
                           person that AirTouch may designate by written notice)
                           at least  weekly of the status of  TowerCo's  efforts
                           and of requested  consents and  inducements  offered.
                           TowerCo shall deliver written  reports,  memoranda or
                           material  correspondence  relating to the  activities
                           described  in  this  schedule  and  of  responses  or
                           counteroffers received from ground lessors and others
                           from whom  consents are  requested.  TowerCo shall be
                           responsible  for compliance  with  applicable Laws in
                           connection  with its activities  under Section 2.2 of
                           the Agreement.

                           AirTouch  will  cooperate in good faith through Jason
                           Wilcox  (or  such  other  person  that  AirTouch  may
                           designate  by written  notice)  who shall  reasonably
                           respond to TowerCo's questions concerning the parties
                           from whom consents are to be requested.  In the event
                           that TowerCo provides AirTouch with a written report,
                           memoranda or material  correspondence  in  connection
                           with a Site for which  TowerCo has  obtained  consent
                           conditioned  upon  AirTouch's  approval  or  consent,
                           written or otherwise ("AirTouch Approval"),  AirTouch
                           shall  provide a written  response to TowerCo  (which
                           shall set forth a good faith  basis for denial if the
                           approval  or consent is denied)  within ten (10) days
                           after the receipt of a written request by TowerCo for
                           AirTouch Approval (an "AirTouch  Approval  Request"),
                           or such Site shall be an Included  Tower for the next
                           applicable  Closing  subject to Section  1.19(c)  and
                           AirTouch  shall take all  necessary  action to ensure
                           that such Site may be closed on;  provided,  however,
                           nothing  contained  herein shall be deemed to require
                           AirTouch to expend any amount  greater  than  $20,000
                           per Tower in  connection  with any AirTouch  Approval
                           Request,   AirTouch   Approval  or  deemed   AirTouch
                           Approval.

     5. The following is hereby inserted before Section 2.3(a):

          For  Towers  included  within a Closing  which  occurred  on or before
          February 15, 2001:


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     6. The following is hereby  inserted  after Section 2.3(a) of the Agreement
to Sublease:

                  TowerCo shall pay the Sublessors $360,000 for the Tower at the
                  Site  designated  on Annex I as PV-386 and the Closing of such
                  Tower shall occur on the first  Subsequent  Closing  following
                  February 15, 2001.

                  For Towers (i) not included within a Closing which occurred on
                  or before  February  15, 2001 and (ii) which are not Towers at
                  Sites  designated  on Annex I as  PV-501,  PV-537,  PV-282  or
                  PV-386:

                    At any  given  Closing,  TowerCo  shall  pay the  Sublessors
                    consideration for each Included Tower that is the subject of
                    such Closing, in the following amounts:

                    (a) $325,000 for each of the first ten (10) Towers for which
                    a Closing occurs after February 15, 2001;

                    (b)  $300,000  for each of the  second  ten (10)  Towers for
                    which a Closing occurs after February 15, 2001; and

                    (c)  $275,000 for each Tower after the first twenty (20) for
                    which a Closing occurs after February 15, 2001.

     7. The following is hereby  inserted before Section 2.3(b) of the Agreement
to Sublease:

     For Towers  included  within a Closing which occurred on or before February
     15, 2001:

     8. The following is hereby  inserted  after Section 2.3(b) of the Agreement
to Sublease:

     Section 2.3(b) shall not apply to Towers closed after February 15, 2001.

     9. The fourth sentence of Section 2.4 of the Agreement to Sublease shall be
deleted in its entirety and replaced with the following:

                  Each  Subsequent  Closing  (i)  which  occurred  on or  before
                  February  15,  2001 shall  involve  no fewer than 45  Included
                  Towers and (ii) which  occurs  after  February  15, 2001 shall
                  involve no fewer  than 10  Included  Towers,  except the Final
                  Closing which may involve fewer than 10 Included Towers.

                  Each  Subsequent  Closing which occurred on or before February
                  15, 2001,  shall occur on months-end  after the month in which
                  the Initial Closing falls (each, a "Subsequent  Closing Date")
                  and with at least ten (10)  Business Days notice from AirTouch
                  to TowerCo being required.

                  Each  Subsequent  Closing which occurs after February 15, 2001
                  (except the Final Closing  which  requires no notice and which
                  shall occur on the Final  Closing  Date) shall occur on a date
                  that TowerCo shall select (that  designated  date also being a

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                  "Subsequent Closing Date") and which in no event shall be less
                  than ten (10)  Business  Days from the date upon which TowerCo
                  delivers  written notice to Jason Wilcox (or such other person
                  that AirTouch may designate by written notice).

     10. The second to last  sentence  and last  sentence  of Section 2.4 of the
Agreement to Sublease  shall be deleted in their  entirety and replaced with the
following sentences:

                  The last Subsequent Closing (the "Final Closing") is scheduled
                  to occur on June 29, 2001 (the "Final Closing  Date").  Unless
                  otherwise  agreed  to  by  the  parties,  each  Closing  after
                  February  15,  2001  shall take  place at  Sublessors'  Orange
                  County, California office located at 15505 Sand Canyon Avenue,
                  Building D, First Floor, Irvine, California 92618.

     11. Section 12.1(e) is hereby deleted in its entirety and replaced with the
following:

                  by either TowerCo or AirTouch,  in the event that all Closings
                  have not  occurred  on or before  June 29, 2001 for any reason
                  other than a breach or default  by such  terminating  party of
                  its   respective   representations,   warranties,   covenants,
                  agreements  or  other  obligations  hereunder,  such  that the
                  conditions to the non-terminating  party's Closing obligations
                  set forth in Section 9.1(a) or 9.1(b), or in Section 8.1(a) or
                  8.1(b), as the case may be, would not be satisfied.

     12. If Closings  occur on 20 or more Towers after  February  15, 2001,  the
parties agree that the Towers at Sites  designated on Annex I as PV-501,  PV-537
and PV-282 will not be Included Towers pursuant to the Agreement to Sublease. If
Closings  do not occur for 20 or more  Towers  after  February  15,  2001,  this
Section  12 shall not have  effect and the  parties  shall not be deemed to have
waived or affected  their rights with respect to the Towers at Sites  designated
on Annex I as PV-501, PV-537, PV-282 as they existed on March 8, 2001.

     13. Except as modified herein, the terms and provisions of the Agreement to
Sublease shall remain in full force and effect without  further  modification or
amendment  whatsoever.  All capitalized terms not otherwise defined herein shall
have the meaning given to them in the Agreement to Sublease.




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         IN WITNESS  WHEREOF,  the parties have  executed  this  Agreement to be
effective as of March 8, 2001.

                   VERIZON WIRELESS (VAW) LLC
                   dba Verizon Wireless

                   BY:  CELLCO PARTNERSHIP, its sole member

                          By:    /s/Richard J. Lynch
                                ------------------------------------
                                              Richard J. Lynch
                                        Executive Vice-President and
                                           Chief Technical Officer

                   LOS ANGELES SMSA LIMITED PARTNERSHIP
                   LOS ANGELES SMSA LIMITED PARTNERSHIP
                   dba AirTouch Wireless

                   BY:  AIRTOUCH CELLULAR, as General Partner

                          By:  /s/Robert F. Swaine
                               -------------------------------------
                          Print Name:   Robert F. Swaine
                                       -----------------------------
                          Title:  Area Vice President, Area Network (Southwest)
                                  ---------------------------------------------

                   OXNARD-VENTURA-SIMI LIMITED PARTNERSHIP
                   dba AirTouch Wireless

                   BY:  AIRTOUCH CELLULAR, as General Partner

                          By:  /s/Robert F. Swaine
                               -------------------------------------
                          Print Name:  Robert F. Swaine
                                       -----------------------------
                          Title:  Area Vice President, Area Network (Southwest)
                                  ---------------------------------------------

                   SPECTRASITE HOLDINGS, INC.

                          By:  /s/Glen F. Spivak
                               --------------------------------------------
                          Print Name:  Glen F. Spivak
                                       ------------------------------------
                          Title:  Vice President
                                  -----------------------------------------

                   CALIFORNIA TOWER, INC.

                          By:      /s/Ralph W. Deppisch
                                   ----------------------------------------
                          Print Name:  Ralph W. Deppisch
                                       ------------------------------------
                          Title:   Vice President General Manager
                                   ----------------------------------------

 [counterpart signature page - March 8, 2001 Amendment to Agreement to Sublease]