AMERICAN RADIO SYSTEMS CORP /MA/
8-K, 1997-12-23
RADIO BROADCASTING STATIONS
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                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                    FORM 8-K


                                 CURRENT REPORT

                       Pursuant to Section 13 or 15(d) of
                       The Securities Exchange Act of 1934

                Date of Report (Date of earliest event reported):
                     December 23, 1997 (November 21, 1997)

                       AMERICAN RADIO SYSTEMS CORPORATION
             (Exact name of registrant as specified in its charter)

    Delaware                      0-26102                    04-3196245
(State or other                  (Commission                (IRS Employer
  jurisdiction of                File Number)             Identification No.)
  incorporation)




                              116 Huntington Avenue
                           Boston, Massachusetts 02116
          (Address of principal executive offices, including zip code)




                                 (617) 375-7500
              (Registrant's telephone number, including area code)






<PAGE>




Item 5.  Other Events

1.  On  December  12,  1997,  American  Tower  Systems  Corporation  ("ATS"),  a
wholly-owned  subsidiary of American Radio Systems Corporation ("ARS"),  entered
into an Agreement and Plan of Merger (the "ATC Merger Agreement") by and between
ATS  and  American  Tower   Corporation   ("ATC"),   an  unaffiliated   Delaware
corporation, pursuant to which ATC will merge with and into ATS, and ATS will be
the surviving  corporation (the "ATC Merger").  Pursuant to the ATC Merger,  ATS
will issue an aggregate of approximately  31.72 million shares of Class A Common
Stock,  $.01 par  value  per  share,  of ATS (the  "ATS  Class A Common  Stock")
(including shares issuable upon exercise of ATC options).  Such number of shares
will represent approximately 35% of the number of shares of common stock, of ATS
(the "ATS  Common  Stock")  which  would be  outstanding  on a pro forma  basis,
assuming the  consummation of the CBS Merger (as defined  below),  including the
Tower  Separation (as defined below),  the Gearon Merger (as defined  below),  a
proposed private  placement of approximately  $80.0 million of ATS Common Stock,
the  exercise  of all  options  to  acquire  ATS  Common  Stock  proposed  to be
outstanding and the conversion of all shares of ARS 7% Convertible  Exchangeable
Preferred  Stock.  Consummation of the ATC Merger is also  conditioned on, among
other things, the expiration or earlier  termination of the waiting period under
the  Hart-Scott-Rodino  Antitrust  Improvements  Act of 1976 (the "HSR Act") and
consummation  of the  Tower  Separation.  The ATC  Merger  also  provides  for a
termination fee of $15.0 million  (together with the reimbursement of reasonable
out-of  pocket  expenses up to an aggregate of $1.0  million)  payable to either
party under certain circumstances.  Such fee is payable to ATC in the event that
the ATC Merger is  terminated  because of failure of the CBS Merger or the Tower
Separation  to occur on or prior to May 31, 1998.  The ATC Merger is expected to
be consummated  in the second quarter of 1998, and ATS will be renamed  American
Tower Corporation upon consummation.

         For more information,  see the ATC Merger Agreement,  which is attached
herewith as Exhibit 2.1,  and the ARS press  release,  dated  December 15, 1997,
which is attached herewith as Exhibit 99.1.

2. On November 21, 1997,  ATS and its  wholly-owned  subsidiary,  American Tower
Systems (Delaware),  Inc. ("ATSI"), entered into an Agreement and Plan of Merger
(the "Gearon  Merger  Agreement")  by and among ATS,  ATSI,  Gearon & Co.,  Inc.
("Gearon"),  a Georgia  corporation,  and J. Michael Gearon,  Jr., the principal
stockholder  of Gearon,  pursuant to which  Gearon will merge with and into ATSI
(the "Gearon Merger").  Pursuant to the Gearon Merger Agreement,  ATS will issue
an aggregate of  approximately  5.333 million shares of ATS Class A Common Stock
and   approximately   $32.0  million  in  cash  for  an  aggregate  agreed  upon
consideration of approximately $80.0 million. Consummation of the transaction is
also conditioned on, among other things,  the expiration or earlier  termination
of the HSR Act waiting period and is expected to occur in January 1998.

         For  more  information,  see the  Gearon  Merger  Agreement,  which  is
attached  herewith as Exhibit 2.2, and the ARS press release,  dated December 3,
1997, which is attached herewith as Exhibit 99.2.



<PAGE>



3. On September 19, 1997, ARS, CBS Corporation  (formerly  Westinghouse Electric
Corporation  ("CBS"))  and R  Acquisition  Corp.  ("CBS  Sub")  entered  into an
Agreement and Plan of Merger (the "Original Merger Agreement") pursuant to which
CBS Sub would be merged  with and into ARS and ARS will become a  subsidiary  of
CBS (the "CBS Merger").  As a condition of the Original Merger Agreement,  prior
to the effective time of the CBS Merger (the "Effective Time"),  ATS, which owns
and operates ARS's  communications  sites business,  would be separated from ARS
and distributed (the "Tower Separation") to the holders of Class A Common Stock,
$.01 par value per share,  Class B Common Stock,  $.01 par value per share,  and
Class C Common Stock, $.01 par value per share, of ARS  (collectively,  the "ARS
Common  Stock").  At the Effective  Time, the holders of ARS Common Stock would,
pursuant to the terms of the Original Merger  Agreement,  be entitled to receive
$44.0 in cash per share of ARS Common  Stock for, in effect,  their  interest in
ARS's radio business.

         On December 18, 1997,  ARS, CBS and CBS Sub entered into an Amended and
Restated Agreement and Plan of Merger (the "Amended  Agreement") to provide that
the Tower  Separation may be  effectuated  (i) through the CBS Merger or (ii) at
ARS'  election,  if the CBS Merger  has not been  consummated  by May 31,  1998,
through  the merger  (the "Tower  Merger")  of ATS Merger  Corporation,  a newly
formed  wholly-owned  subsidiary  of ARS  ("ATS  Merger"),  with and  into  ARS,
pursuant to the  Agreement and Plan of Merger by and between ARS and ATS Merger,
dated as of  December  18,  1997,  which is attached as Exhibit D to the Amended
Agreement. If the Tower Separation is effectuated through the CBS Merger, at the
Effective Time, each holder of ARS Common Stock shall be entitled to receive per
share (i) $44.0 in cash and (ii) one share of ATS Common Stock of the same class
as the  class of ARS  Common  Stock  surrendered.  If the  Tower  Separation  is
effectuated  through the Tower Merger, ARS will redeem, at the effective time of
the Tower Merger (the "Tower Merger  Effective  Time"),  a portion of ARS Common
Stock  in  exchange  for all of the  shares  of ATS  Common  Stock  which  would
otherwise  have been  distributed  to the holders of ARS Common Stock as part of
the CBS Merger.  In such event,  the amount of cash to be received  per share of
ARS Common Stock pursuant to the CBS Merger would be  proportionately  increased
so that each holder of ARS Common Stock will receive  pursuant to the CBS Merger
the same amount of cash he or she would have  received  if the Tower  Merger had
not been  consummated  (assuming no  disposition by such holder of shares of ARS
Common Stock between the Tower Merger  Effective  Time and the Effective  Time).
The provisions with respect to the effectuation of the Tower Separation  through
the CBS Merger or the Tower Merger were added for two reasons: (i) to facilitate
consummation  of the ATC  Merger  (in the  event  the CBS  Merger  has not  been
consummated  by May 31, 1998,  which is the  termination  date of the ATC Merger
Agreement) and (ii) to increase the  likelihood  that such  separation  would be
treated as capital gains for tax purposes. For more information, see Exhibit 2.3
hereto.

         As a result of the request of one of the  holders of ARS Common  Stock,
which  was  aware of the tax  benefit  to  holders  of ARS  Common  Stock of the
provisions  in the  Amended  Agreement,  holders of shares of ARS  Common  Stock
representing  a  majority  of the  voting  power of the shares of the ARS Common
Stock  entitled to vote with respect to such matters  executed and  delivered on
December 19, 1997 written consents  approving and adopting the Amended Agreement
and the Tower  Merger  Agreement  and  approving  the CBS  Merger  and the Tower
Merger, each on the respective terms set forth therein and in accordance with


<PAGE>



Delaware  General  Corporation  Law  (the  "DGCL").   Accordingly,   no  further
stockholder   approval  is  required  and,  therefore,   ARS  will  not  hold  a
stockholder's  meeting and will not seek stockholder proxies with respect to the
Amended Agreement or the Tower Merger Agreement.

         On December 19, 1997,  ARS, CBS and CBS Sub executed an amendment  (the
"First Amendment") to the Amended Agreement  reflecting approval and adoption by
the holders of ARS Common Stock of the Amended Agreement and approval of the CBS
Merger,  changing all references to the term "Proxy  Statement" to  "Information
Statement"  and to the  term  "Tower  Proxy  Statement"  to  "Tower  Information
Statement",  deleting the requirements of meetings of ARS common stockholders to
approve and adopt the  Amended  Agreement  and the Tower  Merger  Agreement  and
approve the transactions  contemplated by each of them, and  acknowledging  that
the Amended Agreement  amended and restated the Original Merger  Agreement.  The
amendment also contained a representation and warranty of ARS to the effect that
the stockholder consents constituted the required vote under the DGCL.
For more information, see Exhibit 2.4.

         The  foregoing  descriptions  of the ATC Merger  Agreement,  the Gearon
Merger  Agreement,  the Amended  Agreement,  the First Amendment,  and the Tower
Merger  Agreement  do not  purport to be  complete  and are  qualified  in their
entirety by the copies of the foregoing  agreements which are attached hereto as
Exhibits.

Item 7.  Financial Statements and Exhibits

         (c).  Exhibits


           Exhibit  2.1 -  Agreement  and  Plan of  Merger,  dated  as of
                           December  12,  1997,  by and between  American  Tower
                           Systems  Corporation,  a  Delaware  corporation,  and
                           American Tower Corporation,  a Delaware  corporation.
                           (Schedules and Exhibits omitted).

           Exhibit  2.2 -  Agreement  and  Plan of  Merger,  dated  as of
                           November  21,  1997,  by  and  among  American  Tower
                           Systems Corporation, a Delaware corporation, American
                           Tower   Systems   (Delaware),    Inc.,   a   Delaware
                           corporation,   Gearon   &  Co.,   Inc.,   a   Georgia
                           corporation,  and J. Michael Gearon,  Jr.  (Schedules
                           and Exhibits omitted).

           Exhibit  2.3 -  Amended  and  Restated  Agreement  and Plan of
                           Merger,  dated as of December 18, 1997,  by and among
                           American  Radio  Systems   Corporation,   a  Delaware
                           Corporation, CBS Corporation (formerly,  Westinghouse
                           Electric  Corporation),  a Pennsylvania  corporation,
                           and  R  Acquisition  Corp.,  a  Delaware  corporation
                           (Schedule  and Exhibits  omitted,  except for Exhibit
                           D).

            Exhibit  2.4 - First  Amendment,  dated  December 19, 1997, to
                           Amended and Restated  Agreement,  dated  December 18,
                           1997 by and among American Radio Systems Corporation,
                           a Delaware Corporation, CBS


<PAGE>



                           Corporation    (formerly,    Westinghouse    Electric
                           Corporation),   a  Pennsylvania  corporation,  and  R
                           Acquisition Corp., a Delaware corporation. (Schedules
                           and Exhibits omitted).


           Exhibit 99.1 -  Press Release, dated as of December 15, 1997.

           Exhibit 99.2 -  Press Release, dated as of December 3, 1997.


<PAGE>





                                   SIGNATURES


Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned hereunto duly authorized.


                            AMERICAN RADIO SYSTEMS
                            CORPORATION
                            (Registrant)


Date: December 23, 1997     By: /s/ Justin D. Benincasa
                                Name: Justin D. Benincasa
                                Title: Vice President and Corporate Controller


                                                                    EXHIBIT 2.1

                          AGREEMENT AND PLAN OF MERGER

                                 By and Between

                       AMERICAN TOWER SYSTEMS CORPORATION

                                       and

                           AMERICAN TOWER CORPORATION

                                   Dated as of

                                DECEMBER 12, 1997



















<PAGE>

<TABLE>
<CAPTION>

                                TABLE OF CONTENTS
                                                                                                               Page
<S>      <C>                                                                                                    <C>

ARTICLE 1

         DEFINED TERMS............................................................................................1

ARTICLE 2

         THE MERGER...............................................................................................2
                  2.1      The Merger.............................................................................2
                  2.2      Closing................................................................................2
                  2.3      Effective Time.........................................................................2
                  2.4      Effect of the Merger...................................................................2
                  2.5      Certificate of Incorporation...........................................................2
                  2.6      Bylaws.................................................................................2
                  2.7      Directors and Officers.................................................................2

ARTICLE 3

         CONVERSION OF SHARES; EXCHANGE OF CERTIFICATES...........................................................3
                  3.1      Conversion of Capital Stock............................................................3
                  3.2      Surrender of Certificates; Payment of Merger Consideration and
                           Preferred Stock Merger Consideration...................................................4
                  3.3      Stock Transfer Books...................................................................4
                  3.4      Dissenting Shares......................................................................5

ARTICLE 4

         REPRESENTATIONS AND WARRANTIES OF ATC ...................................................................5
                  4.1      Organization and Business; Power and Authority; Effect of Transaction..................5
                  4.2      Financial and Other Information.  .....................................................7
                  4.3      Material Statements and Omissions; Absence of Events...................................7
                  4.4      Title to Properties; Leases............................................................8
                  4.5      Compliance with Private Authorizations.................................................9
                  4.6      Compliance with Governmental Authorizations and Applicable Law.........................9
                  4.7      Intangible Assets......................................................................9
                  4.8      Related Transactions..................................................................10
                  4.9      Insurance.............................................................................10
                  4.10     Tax Matters.  ........................................................................10
                  4.11     Employee Retirement Income Security Act of 1974.......................................10
                  4.12     Absence of Sensitive Payments.........................................................12
                  4.13     Bank Accounts, Etc....................................................................12
                  4.14     Employment Arrangements...............................................................13
                  4.15     Material Agreements...................................................................13
                  4.16     Ordinary Course of Business...........................................................13
                  4.17     Material and Adverse Restrictions.....................................................14
                  4.18     Broker or Finder......................................................................15
                  4.19     Solvency..............................................................................15
                  4.20     Environmental Matters.................................................................15
                  4.21     Capital Stock.........................................................................16
 

<PAGE>


                 4.22     State Takeover Statutes...............................................................16


ARTICLE 5

         REPRESENTATIONS AND WARRANTIES OF ATS...................................................................16
                  5.1      Organization and Business; Power and Authority; Effect of Transaction.................16
                  5.2      Financial and Other Information.  ....................................................18
                  5.3      Material Statements and Omissions; Absence of Events..................................18
                  5.4      Title to Properties; Leases...........................................................18
                  5.5      Compliance with Private Authorizations................................................19
                  5.6      Compliance with Governmental Authorizations and Applicable Law........................20
                  5.7      Intangible Assets.....................................................................20
                  5.8      Related Transactions..................................................................20
                  5.9      Insurance.............................................................................21
                  5.10     Tax Matters.  ........................................................................21
                  5.11     Employee Retirement Income Security Act of 1974.......................................21
                  5.12     Absence of Sensitive Payments.........................................................23
                  5.13     Employment Arrangements...............................................................24
                  5.14     Material Agreements...................................................................24
                  5.15     Ordinary Course of Business...........................................................24
                  5.16     Material and Adverse Restrictions.....................................................25
                  5.17     Broker or Finder......................................................................26
                  5.18     Solvency..............................................................................26
                  5.19     Environmental Matters.................................................................26
                  5.20     Capital Stock.........................................................................27
                  5.21     State Takeover Statutes...............................................................27
                  5.22     ATS Private Placement.................................................................27
                  5.23     ARS Organization and Business; Power and Authority; Effect of Transaction.............27

ARTICLE 6

         COVENANTS...............................................................................................29
                  6.1      Access to Information; Confidentiality................................................29
                  6.2      Agreement to Cooperate.  .............................................................30
                  6.3      Public Announcements..................................................................31
                  6.4      Notification of Certain Matters.......................................................31
                  6.5      No Solicitation.......................................................................31
                  6.6      Conduct of Business by ATS Pending the Merger.........................................32
                  6.7      Conduct of Business by ATC Pending the Merger.........................................34
                  6.8      Directors', Officers' and Employees' Indemnification and Insurance....................36
                  6.9      ATC Employees and Benefit Plans.......................................................37
                  6.10     ATC Stock Options.....................................................................38
                  6.11     ATS Voting Agreement.  ...............................................................39
                  6.13     Registration Statement and Proxy/Information Statement.  .............................39
                  6.14     Listing of ATS Class A Common Stock...................................................40
                  6.15     Solicitation of Employees.............................................................40
                  6.16     Additional Tax Matters................................................................40
                  6.17     ATS Registration Rights Agreement.....................................................41
                  6.18     Charter Amendment.....................................................................41

                                       ii

<PAGE>


                  6.19     Conversion of Class B Common Stock....................................................41
                  6.20     ATS Separation Agreement..............................................................41
                  6.21     CBS Merger or Tower Distribution Related Actions......................................41
                  6.22     Efforts Regarding Pending Transactions................................................41
                  6.23     Certain Closing Certificates..........................................................41
                  6.25     Issue of ATS Class B Common Stock.....................................................42
                  6.26     Election of ATS Directors.............................................................42

ARTICLE 7

         CLOSING CONDITIONS......................................................................................42
                  7.1      Conditions to Obligations of Each Party...............................................42
                  7.2      Conditions to Obligations of ATS......................................................43
                  7.3      Conditions to Obligations of ATC.  ...................................................44

ARTICLE 8

         TERMINATION, AMENDMENT AND WAIVER.......................................................................45
                  8.1      Termination...........................................................................45
                  8.2      Effect of Termination.................................................................46

ARTICLE 9

         GENERAL PROVISIONS......................................................................................47
                  9.1      Waivers; Amendments...................................................................47
                  9.2      Fees, Expenses and Other Payments.....................................................47
                  9.3      Notices...............................................................................47
                  9.4      Specific Performance; Other Rights and Remedies.......................................48
                  9.5      Severability..........................................................................48
                  9.6      Counterparts..........................................................................49
                  9.7      Section Headings......................................................................49
                  9.8      Governing Law.........................................................................49
                  9.9      Further Acts..........................................................................49
                  9.10     Entire Agreement......................................................................49
                  9.11     Assignment............................................................................50
                  9.12     Parties in Interest...................................................................50
                  9.13     Non-Survival of Representations, Warranties, Covenants and Agreements.................50


APPENDIX A:                Definitions

EXHIBITS:

         EXHIBIT A:        Certificate of Merger (Section 2.3).
         EXHIBIT B-1:      Existing ATS Restated Certificate of Incorporation (Section 2.5).
         EXHIBIT B-2       Principles on which to restate Existing ATS Restated Certificate of Incorporation
                                    (Section 2.5).
         EXHIBIT C:        ATS Voting Agreement (Section 6.11).
         EXHIBIT D:        ATS Registration Rights Agreement (Section 6.17)

                                       iii

<PAGE>


         EXHIBIT E:        ATC Affiliate Agreement (Section 6.24).
         EXHIBIT F:        Opinion of Vinson & Elkins LLP (Section 7.2(a)).
         EXHIBIT G:        Tax Certificate of ATC and the ATC stockholders (Section 7.2(d)).
         EXHIBIT H:        Opinion of Sullivan & Worcester LLP (Section 7.3(a)).
         EXHIBIT I:        Tax Certificate of ATS (Section 7.3(f)).

                                       iv
</TABLE>

<PAGE>



                          AGREEMENT AND PLAN OF MERGER


         Agreement  and Plan of Merger,  dated as of December 12,  1997,  by and
among American Tower Systems  Corporation,  a Delaware  corporation ("ATS"), and
American Tower Corporation, a Delaware corporation ("ATC").

                              W I T N E S S E T H:

         WHEREAS,  the Boards of Directors of ATC and ATS have  determined  that
the merger (the  "Merger") of ATC into ATS on the terms and conditions set forth
in this Agreement and Plan of Merger (this  "Agreement")  is consistent with and
in furtherance of the long-term  business  strategy of each, and is fair to, and
in the best interests of, ATS, ATC and the stockholders of each; and

         WHEREAS, this Agreement provides that ATC shall be merged with and into
ATS, and ATS shall be the surviving corporation; and

         WHEREAS,  the  Boards of  Directors  of ATC and ATS have  approved  and
adopted this Agreement and have directed that this Agreement be submitted to the
stockholders of ATC and ATS, respectively, for their adoption and approval; and

         WHEREAS,  the Board of Directors of American Radio Systems Corporation,
a Delaware  corporation  ("ARS"),  has approved and adopted this  Agreement  and
approved the Merger on behalf of ARS as the sole stockholder of ATS;

         NOW,   THEREFORE,   in   consideration   of  the   premises   and   the
representations, warranties, covenants and agreements herein contained and other
valuable   consideration,   the   receipt  and   adequacy   whereof  are  hereby
acknowledged,  the  parties  hereto  hereby,  intending  to  be  legally  bound,
represent, warrant, covenant and agree as follows:


                                    ARTICLE 1

                                  DEFINED TERMS

         As used  herein,  unless  the  context  otherwise  requires,  the terms
defined in  Appendix A shall have the  respective  meanings  set forth  therein.
Terms defined in the singular  shall have a comparable  meaning when used in the
plural,  and vice  versa,  and the  reference  to any gender  shall be deemed to
include all genders.  Unless otherwise  defined or the context otherwise clearly
requires,  terms for which  meanings are provided in this  Agreement  shall have
such  meanings  when used in the ATC  Disclosure  Schedule,  the ATS  Disclosure
Schedule and each  Collateral  Document  executed  pursuant hereto or thereto or
otherwise delivered pursuant hereto or thereto. References to "hereof," "herein"
or similar  terms are  intended to refer to the  Agreement  as a whole and not a
particular  section,  and  references  to "this  Section" or "this  Article" are
intended  to  refer  to the  entire  section  or  article  and not a  particular
subsection thereof.


<PAGE>



                                    ARTICLE 2

                                   THE MERGER

         2.1 The Merger.  Upon the terms and subject to the conditions set forth
in this Agreement,  and in accordance with the Delaware General  Corporation Law
(the  "DCL"),  ATC shall be merged with and into ATS. As a result of the Merger,
the separate  corporate  existence of ATC shall cease and ATS shall  continue as
the surviving  corporation in the Merger (sometimes referred to, as such, as the
"Surviving Corporation").

         2.2 Closing.  Unless this Agreement shall have been terminated pursuant
to Section 8.1 and subject to the  satisfaction  or, to the extent  permitted by
Applicable  Law, waiver of the conditions set forth in Article 7, the closing of
the Merger (the  "Closing") will take place, at 10:00 a.m., on the Closing Date,
at the offices of  Sullivan & Worcester  LLP,  One Post Office  Square,  Boston,
Massachusetts 02109, on the date on which the Tower Distribution occurs (whether
by reason of the CBS Merger or otherwise), unless another date, time or place is
agreed to in writing by the  parties.  The date on which the  Closing  occurs is
herein referred to as the "Closing Date."

         2.3 Effective  Time.  Subject to the provisions of this  Agreement,  as
promptly as  practicable  after the Closing,  the parties hereto shall cause the
Merger to be  consummated by filing a Certificate of Merger in the form attached
hereto as Exhibit A and made a part hereof (the "Certificate of Merger") and any
related filings  required under the DCL with the Secretary of State of the State
of Delaware.  The Merger shall become  effective at such time as such  documents
are duly  filed as  aforesaid,  or at such later  time as is  specified  in such
documents (the "Effective Time").

         2.4 Effect of the Merger.  The Merger  shall have the effects  provided
for under the DCL.

         2.5 Certificate of  Incorporation.  Subject to the  consummation of the
Merger,  ATS shall file with the  Secretary of State of the State of Delaware an
Amended and Restated  Certificate of Incorporation,  in the form attached hereto
as Exhibit B-1 and made a part hereof (the "ATS Existing Restated Certificate"),
as amended to  incorporate  the  principles  set forth on Exhibit B-2 and made a
part hereof,  which  principles  will be incorporated in an Amended and Restated
Certificate of Incorporation of ATS (the "ATS Restated  Certificate")  and which
principles  will  control  over  any  provision  in the  Existing  ATS  Restated
Certificate,  which shall be the Certificate of  Incorporation  of the Surviving
Corporation  until  thereafter  changed  or amended  as  provided  therein or by
Applicable Law.

         2.6 Bylaws.  The bylaws of ATS in the form  included as part of Section
2.5 of the ATS Disclosure  Schedule  modified to reflect the change of ATS' name
to "American Tower Corporation" shall be the bylaws of the Surviving Corporation
until amended in accordance  with  Applicable  Law and the Organic  Documents of
ATS.

         2.7 Directors and Officers.  From and after the Effective  Time,  until
successors  are duly elected or appointed and  qualified,  or upon their earlier
resignation  or  removal,  in  accordance  with  Applicable  Law and the Organic
Documents of ATS, (a) the  directors of ATS at the  Effective  Time shall be the
directors of the Surviving Corporation and Fred. R. Lummis and Randall Mays, and
(b) the  officers  of ATS at the  Effective  Time shall be the  officers  of the
Surviving Corporation.



                                       -2-


<PAGE>



                                    ARTICLE 3

                 CONVERSION OF SHARES; EXCHANGE OF CERTIFICATES

         3.1  Conversion of Capital Stock.  At the Effective  Time, by virtue of
the Merger and without any action on the part of ATS or ATC or their  respective
stockholders:

                  (a) Each share of Common Stock,  par value $.01 per share,  of
         ATS (the "ATS Common Stock") issued and outstanding  immediately  prior
         to the Effective Time shall remain outstanding.

                  (b) Each share (each, an "ATC Share" and collectively the "ATC
         Shares") of Class A Common Stock,  par value $.01 per share, of ATC and
         Class B Common Stock,  par value $.01 per share,  of ATC  (collectively
         for both such classes,  the "ATC Common Stock") issued and  outstanding
         immediately prior to the Effective Time (other than Dissenting  Shares)
         shall,  by virtue of the Merger and  without  any action on the part of
         the holder  thereof,  be converted into the right to receive the number
         of shares (the "Merger  Consideration")  of Class A Common  Stock,  par
         value $.01 per share, of ATS (the "ATS Class A Common Stock")  obtained
         by dividing the Aggregate  Merger Shares by the number of shares of ATC
         Common Stock determined on a Fully-Diluted  Basis  immediately prior to
         the Effective Time (the "Exchange Ratio"). The parties acknowledge that
         the Exchange  Ratio has been  determined  to give the ATC  stockholders
         (assuming  there are no Dissenting  Shares) in the aggregate  shares of
         ATS  Class  A  Common   Stock   representing   35%  of  the   Surviving
         Corporation's  outstanding  common stock  determined on a Fully-Diluted
         Basis.

                  (c) Each share of ATC Common  Stock owned by ATS or any of its
         Subsidiaries or ATC or any of its Subsidiaries immediately prior to the
         Effective Time shall automatically be canceled and extinguished without
         any  conversion  thereof  and no  payment  shall be made  with  respect
         thereto.

                  (d) Each share of Senior  Preferred  Stock, par value $.01 per
         share,  of ATC (the "ATC  Preferred  Stock"),  issued  and  outstanding
         immediately  prior to the Effective Time shall, by virtue of the Merger
         and without any action on the part of the holder thereof,  be converted
         into the right to receive cash or other immediately  available funds in
         the amount of $200.00 (the "Preferred Stock Merger Consideration").

         In the event either the Gearon Transaction or the ATS Private Placement
has not been  consummated  prior to the Effective  Time, the parties hereto will
negotiate in good faith to determine  the net effect,  if any, of the failure to
so consummate either or both of the foregoing on the enterprise value of ATS. If
the  parties  agree that the net effect of the  failure of either or both of the
Gearon  Transaction and the ATS Private Placement to occur is a reduction in the
ATS enterprise value, the parties shall also determine an appropriate adjustment
of the number of Aggregate Merger Shares so that the Aggregate Merger Shares, as
adjusted,  constitute a higher  percentage  to reflect the  relative  enterprise
values of ATS and ATC.  The parties  shall  negotiate  in good faith for fifteen
(15) days following the request by either party to do so. Any mater not resolved
within  such  fifteen  (15)-day  period  shall  be  submitted  to  a  nationally
recognized,  independent  investment  banking firm  selected by agreement of the
parties  hereto.  Within five (5) days after the selection of such firm, ATC and
ATS shall each submit to such firm and the other its calculation of its proposed
adjustment,  together with its  methodology.  The parties shall instruct such to
render a final  and  binding  decision  by  selecting  one of the two  submitted
adjustment  proposals that more fairly represents,  in the opinion of such firm,
the  adjustment   required  by  reason  of  the  enterprise   reductions  solely
attributable to the items set forth above. The investment banking firm shall not
have any discretion to select an adjustment  other than one 

                                       -3-


<PAGE>


of the two proposed. The parties shall instruct such firm to render its decision
within  fifteen  (15) days after  submission  of the  adjust.  Each party  shall
cooperate in all reasonable respects with such firm in making its determination.
The  Termination  Date shall be extended to allow for the foregoing  discussions
for the later of the fifteen (15)-day period the parties negotiate in good faith
or, if they fail to reach  agreement,  for the period required by the investment
banking firm to render its decision.

          At the Effective  Time,  all ATC Shares shall no longer be outstanding
and shall  automatically  be canceled and retired and shall cease to exist,  and
certificates  previously  evidencing any such ATC Shares (each, a "Certificate")
shall  thereafter  represent  the right to receive,  upon the  surrender of such
Certificate  in  accordance  with the  provisions  of  Section  3.2,  the Merger
Consideration  multiplied  by the  number  of ATC  Shares  represented  by  such
Certificate,  and a holder of more than one Certificate  shall have the right to
receive  the  Merger  Consideration  multiplied  by the  number  of  ATC  Shares
represented by all such Certificates,  or, in the case of a holder of Dissenting
Shares,  the right to perfect the right to receive payment for Dissenting Shares
pursuant to Section 262 of the DCL. In lieu of any such fractional shares,  each
holder of ATC Common Stock who would  otherwise  have been entitled to receive a
fraction of a share of ATS Class A Common Stock,  upon surrender of Certificates
for  exchange  pursuant  to this  Article,  shall be  entitled to receive a cash
payment equal to such fraction  multiplied by the closing price per share of ATS
Class A Common Stock on the Nasdaq  National  Market  ("Nasdaq") or, if not then
traded on  Nasdaq,  on the  principal  stock  exchange  on which the ATS Class A
Common Stock is admitted to trading, as reported by the Wall Street Journal, for
the first trading day  immediately  following the Effective Time, and the Merger
Consideration to which a holder is entitled shall be deemed to be such number of
shares  of ATS  Class  A  Common  Stock  and  such  cash.  The  holders  of such
Certificates  previously evidencing ATC Shares outstanding  immediately prior to
the  Effective  Time  shall  cease to have any rights  with  respect to such ATC
Shares, except as otherwise provided herein or by Applicable Law.

         At the  Effective  Time,  all shares of ATC  Preferred  Stock  shall no
longer be outstanding and shall  automatically be canceled and retired and shall
cease to exist,  and  certificates  previously  evidencing any such shares shall
thereafter  represent the right to receive,  upon the surrender of  certificates
representing  such shares in accordance  with the provisions of Section 3.2, the
Preferred Stock Merger  Consideration  multiplied by the number of shares of ATC
Preferred Stock represented by such  certificate,  and a holder of more than one
certificate  shall  have  the  right  to  receive  the  Preferred  Stock  Merger
Consideration multiplied by the number of ATC Preferred Stock represented by all
such certificates. The holders of such certificates previously evidencing shares
of ATC Preferred Stock outstanding immediately prior to the Effective Time shall
cease to have any  rights  with  respect  to such  shares,  except as  otherwise
provided herein or by Applicable Law.

         3.2  Surrender of  Certificates;  Payment of Merger  Consideration  and
Preferred  Stock Merger  Consideration.  At and after the  Effective  Time,  the
Surviving  Corporation  shall  issue to each  holder of ATC Common  Stock,  upon
surrender  of each of his or its  Certificates,  a  certificate  of ATS  Class A
Common  Stock  representing  the Merger  Consideration  with  respect to the ATC
Shares  represented  by such  Certificate  in accordance  with the provisions of
Section  3.1,  plus cash in amount  sufficient  to make  payment for  fractional
shares. In addition,  the Surviving  Corporation shall pay to each holder of ATC
Preferred  Stock,  upon  surrender  of his or its stock  certificate  evidencing
ownership of ATC Preferred Stock, in cash or immediately available funds by wire
transfer  to an account or  accounts  designated  by ATC to ATS at least two (2)
Business Days prior to the Closing,  the sum of $200.00 multiplied by the number
of shares of ATC Preferred Stock evidenced by such certificate. In the event any
ATC stockholder  has not delivered the certificate  referred to in Section 6.28,
the  Surviving   Corporation   shall  be  entitled  to  withhold  from  delivery
certificates  for the ATS Class A Common Stock to which such  stockholder  would
otherwise be entitled,  a number of shares of ATS 


                                       -4-


<PAGE>

Class A Common Stock required to enable the Surviving Corporation to comply with
the applicable provisions of the Code.

         3.3 Stock  Transfer  Books.  At the Effective  Time, the stock transfer
books of ATC shall be closed,  and there shall be no further  transfer of shares
of ATC Common Stock or ATC Preferred Stock thereafter on the records of ATC. Any
Certificates  representing ATC Shares or certificates representing shares of ATC
Preferred  Stock  presented  after  the  Effective  Time for  transfer  shall be
canceled and  exchanged  for the amount to which the ATC Shares or shares of ATC
Preferred Stock  represented  thereby shall be entitled pursuant to Sections 3.1
and 3.2.

         3.4 Dissenting Shares.

                  (a)  Notwithstanding  any other provision of this Agreement to
         the  contrary,   shares  of  ATC  Common  Stock  that  are  outstanding
         immediately  prior  to the  Effective  Time and  which  are held by ATC
         stockholders  who  shall  have not  voted in  favor  of the  Merger  or
         consented  thereto in writing  and who shall be  entitled  to and shall
         have demanded  properly in writing  appraisal rights for such shares of
         ATC Common  Stock in  accordance  with  Section  262 of the DCL and who
         shall not have  withdrawn  such  demand  or  otherwise  have  forfeited
         appraisal rights (collectively,  the "Dissenting Shares"), shall not be
         converted   into  or   represent   the  right  to  receive  the  Merger
         Consideration  payable in  respect  of each  share of ATC Common  Stock
         represented thereby. Such ATC stockholders shall be entitled to receive
         payment of the appraised  value of such shares of ATC Common Stock held
         by them  in  accordance  with  the  provisions  of the  DCL;  provided,
         however,  that all Dissenting Shares held by ATC stockholders who shall
         have  failed  to  perfect  or who  effectively  shall  have  withdrawn,
         forfeited or lost their appraisal rights with respect to such shares of
         ATC Common  Stock under the DCL shall  thereupon be deemed to have been
         converted into and to have become exchangeable for, as of the Effective
         Time, the right to receive,  without any interest  thereon,  the Merger
         Consideration upon surrender, in the manner provided in Section 3.2, of
         the Certificates with respect to such shares.

                  (b) ATC  shall  give ATS  prompt  notice  of any  demands  for
         appraisal rights received by it,  withdrawals of such demands,  and any
         other  instruments  served  pursuant to the DCL and received by ATC and
         relating  thereto.  ATC shall  give ATS the  opportunity  to direct all
         negotiations  and  proceedings  with  respect to demands for  appraisal
         rights under the provisions of the DCL. ATC shall not,  except with the
         prior  written  consent of ATS,  make any payment  with  respect to any
         demands for appraisal rights,  or offer to settle, or settle,  any such
         demands.

         3.5 Option  Securities and Convertible  Securities;  Payment Rights. At
the Effective Time,  subject to the provisions of Section 6.10, each outstanding
Option  Security and each  Convertible  Security of ATC, if any,  whether or not
then  exercisable  for or convertible  into ATC Shares or other ATC  securities,
outstanding  immediately  prior to the  Effective  Time,  shall be canceled  and
retired and shall cease to exist,  and the holder  thereof shall not be entitled
to receive any consideration therefor.




                                       -5-


<PAGE>


                                    ARTICLE 4

                      REPRESENTATIONS AND WARRANTIES OF ATC

         ATC  hereby  represents  and  warrants  to ATS  as  follows  (it  being
understood  and agreed by the  parties  that,  except as the  context  otherwise
requires,  the  representations  and warranties of ATC set forth in this Article
shall apply to each of its Subsidiaries with the same force and effect as though
each of them were named in each Section hereof):

         4.1  Organization  and  Business;   Power  and  Authority;   Effect  of
Transaction.

                  (a) ATC is a corporation duly organized,  validly existing and
         in good standing under the laws of its  jurisdiction  of  organization,
         has all requisite  power and authority  (corporate and other) to own or
         hold under  lease its  properties  and to conduct  its  business as now
         conducted  and is duly  qualified  and in good  standing  as a  foreign
         corporation in each other  jurisdiction  (as shown on Section 4.1(a) of
         the ATC  Disclosure  Schedule)  in which the  character of the property
         owned or  leased  by it or the  nature of its  business  or  operations
         requires such qualification, except for such qualifications the failure
         of which to obtain,  individually or in the aggregate, would not have a
         Material Adverse Effect on ATC.

                  (b) ATC has all requisite  power and authority  (corporate and
         other) and has in full force and effect all Governmental Authorizations
         and  Private  Authorizations  necessary  to  enable it to  execute  and
         deliver,  and to perform its obligations under, this Agreement and each
         Collateral  Document executed or required to be executed by it pursuant
         hereto or thereto and to consummate the  Transactions to which ATC is a
         party;  and the execution,  delivery and  performance of this Agreement
         and each Collateral  Document executed or required to be executed by it
         pursuant  hereto or thereto have been duly  authorized by all requisite
         corporate or other  action on the part of ATC,  other than the approval
         of the  stockholders of ATC, and no other corporate  proceedings on the
         part  of  ATC  are  necessary  to  authorize   this  Agreement  or  the
         transactions  contemplated  hereby or to  consummate  the Merger or the
         other  transactions  so  contemplated  (other than, with respect to the
         Merger,  the ATC Required Vote).  This Agreement has been duly executed
         and  delivered by ATC and  constitutes,  and each  Collateral  Document
         executed or required to be executed by it pursuant hereto or thereto or
         to consummate the Transactions  when executed and delivered by ATC will
         constitute, legal, valid and binding obligations of ATC, enforceable in
         accordance with their respective terms,  except as such  enforceability
         may be subject to bankruptcy, moratorium,  insolvency,  reorganization,
         arrangement,  voidable  preference,  fraudulent  conveyance  and  other
         similar  laws  relating to or  affecting  the rights of  creditors  and
         except as the same may be subject  to the effect of general  principles
         of equity.  The  provisions of Section 203 of the DCL will not apply to
         ATC by reason of this  Agreement or the Merger.  As of the date hereof,
         the Board of  Directors  of ATC,  at a meeting  duly called and held at
         which a quorum was present throughout, has approved the Merger and this
         Agreement,  and has recommended that the ATC  stockholders  approve and
         adopt  this  Agreement  and  the  transactions   contemplated   hereby,
         including  without  limitation the Merger and the ATC Voting  Agreement
         and the acquisition by ATS of the "beneficial"  ownership  contemplated
         thereby.

                  (c)  Except  as  set  forth  in  Section  4.1(c)  of  the  ATC
         Disclosure Schedule,  neither the execution and delivery by ATC of this
         Agreement  or  any  Collateral  Document  executed  or  required  to be
         executed by it pursuant hereto or thereto,  nor the consummation of the
         Transactions  by ATC, nor  compliance  with the terms,  conditions  and
         provisions hereof or thereof by ATC:


                                       -6-


<PAGE>


                           (i) will  conflict  with,  or  result  in a breach or
                  violation  of, or  constitute  a default  under,  any  Organic
                  Document of ATC or any Applicable  Law, or will conflict with,
                  or result in a breach or violation of, or constitute a default
                  under,  or  permit  the  acceleration  of  any  obligation  or
                  liability in, or but for any  requirement  of giving of notice
                  or passage of time or both  would  constitute  such a conflict
                  with,  breach or violation of, or default under, or permit any
                  such acceleration in, any Material Agreement of ATC; or

                           (ii)  will   require   ATC  to  make  or  obtain  any
                  Governmental  Authorization,  Governmental  Filing or  Private
                  Authorization  including  without  limitation  under  the FCA,
                  except as required by the Hart-Scott-Rodino Act and other than
                  any of the foregoing that have been obtained.

                  (d)  Except  as  set  forth  in  Section  4.1(d)  of  the  ATC
         Disclosure Schedule, ATC does not have any Subsidiaries,  each of which
         is (i) wholly-owned unless noted otherwise in Section 4.1(d) of the ATC
         Disclosure  Schedule,  (ii) a  corporation  which  is  duly  organized,
         validly  existing and in good standing under the laws of the respective
         state of incorporation set forth opposite its name on Section 4.1(d) of
         the ATC  Disclosure  Schedule,  and (iii)  duly  qualified  and in good
         standing as a foreign  corporation in each other jurisdiction (as shown
         on  Section  4.1(d)  of the  ATC  Disclosure  Schedule)  in  which  the
         character  of the  property  owned or leased by it or the nature of its
         business or operations requires such qualification, with full power and
         authority (corporate and other) to carry on the business in which it is
         engaged, except for such qualifications the failure of which to obtain,
         individually  or in the  aggregate,  would not have a Material  Adverse
         Effect on ATC. ATC owns, directly or indirectly, all of the outstanding
         capital stock and equity  interests (as shown in Section  4.1(d) of the
         ATC  Disclosure  Schedule)  of each  Subsidiary,  free and clear of all
         Liens (except for  Permitted  Liens or except as described in the notes
         to the ATC Financial  Statements or set forth in Section  4.1(d) of the
         ATC Disclosure Schedule),  and all such stock or other equity interests
         has been duly  authorized  and  validly  issued  and is fully  paid and
         nonassessable.   There  are  no   outstanding   Option   Securities  or
         Convertible  Securities,  or agreements or understandings of any nature
         whatsoever,  relating to the  authorized  and  unissued or  outstanding
         capital stock or equity interests of any Subsidiary of ATC.

         4.2 Financial and Other Information.  The financial  statements of ATC,
furnished  by ATC,  and  included  in the ATS  Information  Statement  (the "ATC
Financial  Statements"),  including  in each case the notes  thereto,  have been
prepared in accordance  with GAAP applied on a consistent  basis  throughout the
periods  covered  thereby,  except as otherwise noted therein or as set forth in
Section 4.2 of the ATC Disclosure  Schedule,  and fairly present in all material
respects the financial  condition and the results of operations and cash flow of
ATC, on the bases therein stated,  as of the respective  dates thereof,  and for
the  respective  periods  covered  thereby  subject,  in the  case of  unaudited
financial  statements,  to normal  nonmaterial  year-end audit  adjustments  and
accruals.

         4.3 Material Statements and Omissions;  Absence of Events.  Neither any
representation  or  warranty  made by ATC  contained  in this  Agreement  or any
certificate,  document or other instrument or other information  furnished or to
be  furnished  by ATC  pursuant  to the  provisions  hereof  (including  without
limitation  information  with respect to ATC  furnished for inclusion in the ATS
Prospectus and the ATS Registration  Statement) nor the ATC Disclosure  Schedule
or the ATC Business Description contains or will contain any untrue statement of
a material  fact or omits or will omit to state any  material  fact  required to
make any statement  contained herein or therein,  in light of the  circumstances
under  which they were made,  not

                                       -7-


<PAGE>

misleading;  provided,  however,  that to the extent  that any such  information
contains any financial  projections,  ATC represents and warrants only that such
projections  have been  prepared in good faith on the basis of the ATC Financial
Statements  and other  information  and  assumptions  which ATC  believes  to be
reasonable.  Since the date of the most recent financial statements constituting
a part  of the ATC  Financial  Statements,  except  to the  extent  specifically
described  in  Section  4.3 of the ATC  Disclosure  Schedule,  there has been no
change in ATC which has had a Material  Adverse Effect on ATC. There is no Event
known to ATC which has had,  or (so far as ATC can now  reasonably  foresee)  is
likely  to  have,  a  Material  Adverse  Effect  on ATC,  except  to the  extent
specifically  described in Section 4.3 of the ATC Disclosure Schedule and except
for matters  affecting the tower rental,  ownership  and  construction  industry
generally, including without limitation competition, regulation and resources or
events arising out of the execution or public announcement of this Agreement.

         4.4 Title to Properties; Leases.

                  (a) ATC has, to ATC's knowledge,  good and indefeasible  title
         to all of its real property  (other than  leasehold  real property) and
         good  title to all of its other  assets  (other  than  real  property),
         tangible and intangible  (the "ATC Assets");  all of such real property
         and other  assets  are so owned,  in each  case,  free and clear of all
         Liens,  except (i)  Permitted  Liens,  and (ii) Liens  described in the
         notes to the ATC Financial Statements or set forth on Section 4.4(a) of
         the ATC Disclosure Schedule. Except for financing statements evidencing
         Liens referred to in the preceding  sentence,  no financing  statements
         under the Uniform  Commercial  Code and no other filing which names ATC
         as debtor or which covers or purports to cover any of the ATC Assets is
         on file in any state or other  jurisdiction,  and ATC has not signed or
         agreed to sign any such financing  statement or filing or any agreement
         authorizing  any secured party  thereunder  to file any such  financing
         statement or filing.  Except as disclosed in Section  4.4(a) of the ATC
         Disclosure  Schedule,  all  improvements  on the real property owned or
         leased by ATC are, to ATC's  knowledge,  in compliance  with applicable
         zoning,  wetlands and land use laws,  ordinances  and  regulations  and
         applicable title covenants,  conditions,  restrictions and reservations
         in all  respects  necessary  to conduct  the  operations  as  presently
         conducted,  except for any instances of non-compliance which do not and
         will not in the aggregate have a Material Adverse Effect on ATC. Except
         as described in the notes to the ATC Financial  Statements or disclosed
         in  Section   4.4(a)  of  the  ATC  Disclosure   Statement,   all  such
         improvements   comply  with  all  Applicable   Laws,  ATC  Governmental
         Authorizations   and   ATC   Private   Authorizations,   except   where
         noncompliance  is not  reasonably  likely  to have a  Material  Adverse
         Effect on ATC. There is no pending or, to ATC's  knowledge,  threatened
         or  contemplated  action  to take by  eminent  domain or  otherwise  to
         condemn any part of any real property  constituting a material  portion
         of the real  property  owned by ATC or,  to ATC's  knowledge,  any real
         property  leased by ATC.  Except as  described  in the notes to the ATC
         Financial  Statements  or set  forth  in  Section  4.4(a)  of  the  ATC
         Disclosure  Schedule,  such real property (other than land),  fixtures,
         fixed assets and other material items of personal  property,  including
         equipment, have, in ATC's reasonable business judgment, been maintained
         in a manner consistent with customary  industry practices and currently
         permit the business of ATC (the "ATC  Business")  to be operated in all
         material  respects in accordance  with the terms and  conditions of all
         Applicable  Laws,  ATC  Governmental  Authorizations  and  ATC  Private
         Authorizations.

                  (b) Each Lease or other  occupancy  or other  agreement  under
         which ATC holds real or personal  property  constituting  a part of the
         ATC Assets  has been duly  authorized,  executed  and  delivered  by or
         assigned  to ATC and,  to ATC's  knowledge,  each of the other  parties
         thereto,  and is a legal,  valid and binding obligation of ATC, and, to
         ATC's  knowledge,  each of the other parties  thereto,  enforceable  in
         accordance with its terms, except as such enforceability may be limited
         by 

                                       -8-


<PAGE>

         bankruptcy,  moratorium,  insolvency  and similar  laws  affecting  the
         rights and remedies of creditors and  obligations of debtors  generally
         and by general principles of equity , and except for such exceptions to
         the foregoing as,  individually  or in the aggregate,  have not had and
         will not have  any  Material  Adverse  Effect  on ATC.  ATC has a valid
         leasehold  interest in and enjoys peaceful and  undisturbed  possession
         under all Leases  pursuant to which it holds any such real  property or
         tangible personal property, subject to the terms of each such Lease and
         Applicable  Law and except for such  exceptions  to the  foregoing  as,
         individually  or in the  aggregate,  have not had and will not have any
         Material  Adverse  Effect  on ATC.  All of such  Leases  are  valid and
         subsisting and in full force and effect,  and neither ATC nor, to ATC's
         knowledge,  any other  party  thereto,  is in  material  default in the
         performance,  observance or fulfillment of any obligation,  covenant or
         condition  contained in any such Lease,  except for such  exceptions to
         the foregoing as,  individually  or in the aggregate,  have not had and
         will not have any Material Adverse Effect on ATC.

         4.5  Compliance  with  Private  Authorizations.  ATC has  obtained  all
Private Authorizations  (collectively,  the "ATC Private  Authorizations") which
are necessary for the ownership or operation of the ATC Assets or the conduct of
the ATC Business which, if not obtained and maintained,  could,  individually or
in the aggregate, be reasonably likely to have a Material Adverse Effect on ATC.
All of the ATC Private  Authorizations are valid and in good standing and are in
full force and effect,  except for such exceptions as are not reasonably  likely
to have a Material  Adverse Effect on ATC. ATC is not in breach or violation of,
or in default in the performance,  observance or fulfillment of, any ATC Private
Authorization,  and no Event exists or has occurred,  which constitutes,  or but
for any  requirement  of  giving  of notice  or  passage  of time or both  would
constitute,  such  a  breach,  violation  or  default,  under  any  ATC  Private
Authorization,  except for such  defaults,  breaches or violations as do not and
are not reasonably  likely to have in the aggregate a Material Adverse Effect on
ATC.  No ATC  Private  Authorization  is the subject of any pending or, to ATC's
knowledge,  threatened  attack,  revocation  or  termination,  except  for  such
exceptions as are not  reasonably  likely to have a Material  Adverse  Effect on
ATC.

         4.6 Compliance with Governmental Authorizations and Applicable Law.

                  (a)  ATC  has   obtained   all   Governmental   Authorizations
         (collectively,   the  "ATC  Governmental   Authorizations")  which  are
         necessary  for the  ownership  or  operation  of the ATC  Assets or the
         conduct of the ATC Business as now conducted and which, if not obtained
         and  maintained,  would,  individually  or in the  aggregate,  have any
         Material   Adverse  Effect  on  ATC.  None  of  the  ATC   Governmental
         Authorizations  is subject to any  restriction or condition which would
         limit in a material  respect the  ownership  or  operations  of the ATC
         Assets or the  conduct  of the ATC  Business  as  currently  conducted,
         except for  restrictions  and  conditions  generally  applicable to ATC
         Governmental   Authorizations   of  such  type.  The  ATC  Governmental
         Authorizations  are valid and in good  standing,  are in full force and
         effect  and  are not  impaired  by any  act or  omission  of ATC or its
         officers,  directors,   employees  or  agents,  and  the  ownership  or
         operation  of the ATC Assets or the conduct of the ATC  Business are in
         accordance with the ATC  Governmental  Authorizations,  except for such
         exceptions to the foregoing as, individually or in the aggregate,  have
         not had and will  not have any  Material  Adverse  Effect  on ATC.  All
         material reports, forms and statements required to be filed by ATC with
         all  Authorities  with respect to the ATC Business  have been filed and
         are true,  complete  and  accurate  in all  material  respects.  No ATC
         Governmental  Authorization  is the subject of any pending or, to ATC's
         knowledge,  threatened  challenge or  proceeding to revoke or terminate
         any ATC  Governmental  Authorization  which,  if revoked or terminated,
         would have a Material Adverse Effect on ATC.

                                       -9-


<PAGE>


                  (b) ATC is in  compliance  with all  Applicable  Laws,  except
         where such noncompliance, individually or in the aggregate, has not had
         and is not  reasonably  like to have a Material  Adverse Effect on ATC.
         Except as set forth in Section 4.6(b) of the ATC  Disclosure  Schedule,
         there are no Legal  Actions of any kind pending or, to the knowledge of
         ATC, threatened at law, in equity or before any Authority against ATC.

         4.7  Intangible  Assets.  Except as set forth in Section 4.7 of the ATC
Disclosure   Schedule,   no   Intangible   Assets   (except   ATC   Governmental
Authorizations and ATC Private Authorizations) are required for the ownership or
operation  of the ATC Assets or the  conduct of the ATC  Business  as  currently
owned,  operated and conducted,  except for such exceptions to the foregoing as,
individually  or in the  aggregate,  have not had and will not have any Material
Adverse Effect on ATC. ATC does not, to its knowledge,  wrongfully infringe upon
or unlawfully use any Intangible Assets owned or claimed by another, and ATC has
not  received  any  notice of any  claim or  infringement  relating  to any such
Intangible  Asset,  except  from  ATS and  except  for  such  exceptions  to the
foregoing as,  individually or in the aggregate,  have not had and will not have
any Material Adverse Effect on ATC.

         4.8  Related  Transactions.  ATC  is  not a  party  or  subject  to any
Contractual  Obligation relating to the ownership or operation of the ATC Assets
or the  conduct  of the  ATC  Business  between  ATC  and  any of its  officers,
directors or  stockholders  or, to the  knowledge  of ATC, any  Affiliate of any
thereof,  including without limitation any Contractual  Obligation providing for
the  furnishing of services to or by,  providing  for rental of property,  real,
personal or mixed,  to or from,  or  providing  for the lending or  borrowing of
money to or from or otherwise  requiring  payments to or from,  any such Person,
other than (i)  Employment  Arrangements  listed or described in Section 4.14 of
the ATC Disclosure Schedule, (ii) Contractual Obligations between ATC and any of
its  directors,  stockholders  or  officers  or  any  Affiliate  of  any  of the
foregoing,  which will be terminated, at no cost or expense to ATC, prior to the
Closing,  (iii) as  specifically  set forth in Section 4.8 of the ATC Disclosure
Schedule,  or (iv) transactions  related to payments that are a part of the $5.0
million allowance described in Section 6.0(a)(iv)(A).

         4.9 Insurance.  ATC  maintains,  with respect to the ATC Assets and the
ATC Business, policies of fire and extended coverage and casualty, liability and
other forms of  insurance  in such  amounts and against such risks and losses as
are customary for companies engaged in similar businesses.

         4.10 Tax Matters.

                  (a) ATC has in accordance  with all Applicable  Laws filed all
         Tax  Returns  which are  required  to be filed,  and has paid,  or made
         adequate  provision for the payment of, all Taxes which have become due
         and payable  pursuant  to said Tax  Returns and all other  governmental
         charges and  assessments  received to date other than those Taxes being
         contested in good faith for which  adequate  provision has been made on
         the most recent balance sheet forming part of ATC Financial Statements.
         The Tax Returns of ATC have been  prepared in all material  respects in
         accordance with all Applicable Laws. All Taxes which ATC is required by
         law to withhold and collect have been duly withheld and collected,  and
         have been paid over, in a timely manner,  to the proper  Authorities to
         the extent due and payable.  ATC has not executed any waiver to extend,
         or  otherwise  taken or failed to take any  action  that would have the
         effect of extending,  the applicable  statute of limitations in respect
         of any Tax  liabilities  of ATC  for  the  fiscal  years  prior  to and
         including  the  most  recent  fiscal  year.  ATC is  not a  "consenting
         corporation"  within the meaning of Section 341(f) of the Code. ATC has
         at all times been taxable as a Subchapter C corporation under the Code,
         and has never been a member of any 

                                      -10-


<PAGE>


         consolidated  group for Tax purposes,  except as otherwise set forth in
         Section 4.10(a) of the ATC Disclosure Schedule.

                  (b) Federal and state  income Tax Returns of ATC have not been
         examined by the IRS or applicable state Authority, and ATC has not been
         notified  of any  proposed  examination,  except  as shown  in  Section
         4.10(b) of the ATC Disclosure Schedule.

                  (c)  ATC is  not a  party  to any  tax  sharing  agreement  or
         arrangement with any other Person.

                  (d) All of the ATC stockholders are "U.S.  persons" within the
         meaning of Section 7701(a)(30) of the Code.

         4.11 Employee Retirement Income Security Act of 1974.

                  (a) ATC (which for purposes of this Section  shall include any
         ERISA Affiliate of ATC) currently  sponsors,  maintains and contributes
         only to the Plans and Benefit Arrangements set forth in Section 4.11(a)
         of the ATC Disclosure Schedule.  ATC has delivered or made available to
         ATS true,  complete  and  correct  copies of (i) each Plan and  Benefit
         Arrangement  (or,  in  the  case  of any  unwritten  Plans  or  Benefit
         Arrangements,  reasonable  descriptions  thereof),  (ii)  the two  most
         recent  annual  reports  on Form  5500  (including  all  schedules  and
         attachments  thereto)  filed with the  Internal  Revenue  Service  with
         respect to each Plan (if any such  report was  required  by  Applicable
         Law),  (iii) the most  recent  summary  plan  description  (or  similar
         document)  for each Plan for which such a summary plan  description  is
         required  by  Applicable   Law  or  was  otherwise   provided  to  plan
         participants  or  beneficiaries,  and (iv)  each  trust  agreement  and
         insurance or annuity contract or other funding or financing arrangement
         relating to any Plan.  To the knowledge of ATC, each such Form 5500 and
         each such summary plan  description (or similar  document) does not, as
         of the date hereof,  contain any material  misstatements.  ATC does not
         contribute to or have an  obligation  to contribute  to, and has not at
         any time  within  six (6)  years  prior  to the date of this  Agreement
         contributed  to or had an  obligation  to  contribute  to,  and no Plan
         listed in Section  4.11(a) of the ATC  Disclosure  Schedule  is, (i) an
         employee  pension  benefit  plan within the meaning of Section  3(2) of
         ERISA,  (ii) a  Multiemployer  Plan, or (iii) a Plan subject to Section
         412 of the Code,  Section 302 of ERISA or Title IV of ERISA. ATC has no
         actual or  potential  liability  under Title IV of ERISA.  ATC does not
         maintain  any Plan that  provides for  post-retirement  medical or life
         insurance  benefits,  and ATC does not have any obligation or liability
         with respect to any such Plan  previously  maintained by ATC, except as
         the  provisions  of COBRA may  apply to any  former  employees  of ATC.
         Except as set forth in Section 4.11(a) of the ATC Disclosure  Schedule,
         as to all Plans and Benefit  Arrangements  listed in Section 4.11(a) of
         the ATC Disclosure Schedule:

                           (i) all such Plans and  Benefit  Arrangements  comply
                  and  have  been  administered  in  form  and in  operation  in
                  accordance  with  their   respective   terms,   and  with  all
                  Applicable  Laws,  in all material  respects,  and ATC has not
                  received   any  notice  from  any   Authority   disputing   or
                  investigating such compliance;

                           (ii) none of the assets of any such Plan are invested
                  in employer securities or employer real property;

                                      -11-


<PAGE>

                           (iii) there are no Claims (other than routine  Claims
                  for benefits or actions seeking qualified  domestic  relations
                  orders) pending or, to ATC's knowledge,  threatened  involving
                  such  Plans  or the  assets  of  such  Plans,  and,  to  ATC's
                  knowledge,  no facts exist which are reasonably likely to give
                  rise  to any  such  Claims  (other  than  routine  Claims  for
                  benefits  or  actions  seeking  qualified  domestic  relations
                  orders);

                           (iv) all  material  contributions  to,  and  material
                  payments  from,  the Plans and Benefit  Arrangements  that may
                  have been required to be made in accordance  with the terms of
                  the  Plans  and  Benefit  Arrangements,   and  any  applicable
                  collective  bargaining  agreement,  have been  made.  All such
                  contributions  to, and  payments  from,  the Plans and Benefit
                  Arrangements,  except  those  payments to be made from a trust
                  qualified  under  Section  401(a) of the Code,  for any period
                  ending  before the Closing Date that are not yet, but will be,
                  required to be made, will be properly accrued and reflected on
                  the financial books and records of ATC;

                           (v) No act,  omission  or  transaction  has  occurred
                  which would result in  imposition  on ATC of (A) any breach of
                  fiduciary duty  liability  damages under Section 409 of ERISA,
                  (B) a civil penalty assessed  pursuant to subsections (c), (i)
                  or (l) of Section 502 of ERISA or (C) a tax  imposed  pursuant
                  to Chapter 43 of Subtitle D of the Code;

                           (vi) ATC has not incurred any material liability to a
                  Plan  (other  than  for   contributions  not  yet  due)  which
                  liability has not been fully paid or accrued for payment as of
                  the date hereof;

                           (vii)  except  as  otherwise   contemplated  by  this
                  Agreement or the ATC Disclosure Schedule, no current or former
                  employee of ATC will be entitled to any additional benefits or
                  any  acceleration  of the time of  payment  or  vesting of any
                  benefits under any Plan or Benefit  Arrangement as a result of
                  the transactions contemplated by this Agreement;

                           (viii) no  compensation  payable by ATC to any of its
                  employees  under  any  existing  Plan,   Benefit   Arrangement
                  (including by reason of the transactions  contemplated hereby)
                  will be subject to  disallowance  under Section  162(m) of the
                  Code;

                           (ix) any amount  that could be  received  (whether in
                  cash or property or the  vesting of  property)  as a result of
                  any of the transactions  contemplated by this Agreement by any
                  employee,  officer,  director or independent contractor of ATC
                  who is a "disqualified individual" (as such term is defined in
                  proposed  Treasury  Regulation  Section  1.280G-1)  under  any
                  employment  arrangement  would  not  be  characterized  as  an
                  "excess parachute payment" (as such term is defined in Section
                  280G(b)(1)  of the  Code),  except  for  any  amount  that  is
                  approved by the  stockholders  of ATC on or before the Closing
                  Date in the manner provided in Section 280G(b)(5) of the Code;
                  and

                           (x) there are no outstanding  options (or contractual
                  obligations  to issue  options) to acquire ATC Common Stock or
                  other ATC  securities  other than options held by employees or
                  directors of ATC and issued under  Benefit  Arrangements  (the
                  aggregate  number of which are as set forth in Section 4.11(a)
                  of the ATC Disclosure Schedule).

                                      -12-


<PAGE>


                  (b) The  execution,  delivery and  performance  by ATC of this
         Agreement  and the  Collateral  Documents  executed  or  required to be
         executed  by ATC  pursuant  hereto and  thereto  will not  involve  any
         prohibited  transaction  within the meaning of ERISA or Section 4975 of
         the Code with respect to any Plan listed in Section  4.11(a) of the ATC
         Disclosure Schedule.

         4.12  Absence  of  Sensitive  Payments.   Neither  ATC  nor,  to  ATC's
knowledge,  any  of  its  officers,   directors,   employees,  agents  or  other
representatives, has with respect to the ATC Assets or the ATC Business (a) made
any  contributions,  payments  or  gifts  to or  for  the  private  use  of  any
governmental official, employee or agent where either the payment or the purpose
of such  contribution,  payment or gift is illegal  under the laws of the United
States or the  jurisdiction  in which made or (b)  established or maintained any
unrecorded fund or asset for any illegal purpose or made any false or artificial
entries on its books.

         4.13 Bank Accounts,  Etc.  Section 4.13 of the ATC Disclosure  Schedule
contains a true,  accurate and complete list as of the date hereof of all banks,
trust companies,  savings and loan associations and brokerage firms in which ATC
has an account or a safe deposit box and the names of all Persons  authorized to
draw thereon, to have access thereto, or to authorize  transactions therein, the
names of all Persons,  if any,  holding valid and subsisting  powers of attorney
from ATC and a summary statement as to the terms thereof.

         4.14  Employment  Arrangements.  Section  4.14  of the  ATC  Disclosure
Schedule contains a true, accurate and complete list of all employees of ATC and
its  Subsidiaries  as of the  date  of this  Agreement  (the  "ATC  Employees"),
together with each such  employee's  title or the capacity in which he or she is
employed  and  each  such  employee's  compensation.  ATC has no  obligation  or
liability,  contingent or other,  under any Employment  Arrangement with any ATC
Employee, other than (i) those listed or described in Section 4.11(a) or Section
4.14 of the ATC  Disclosure  Schedule,  (ii) those  incurred in the ordinary and
usual course of business, or (iii) such obligations or liabilities as do not and
will not have, in the aggregate,  any Material  Adverse Effect on ATC. Except as
described in Section 4.14 of the ATC  Disclosure  Schedule,  (a) none of the ATC
Employees is now, or since  January 1, 1995 has been,  represented  by any labor
union or other employee collective bargaining organization,  and ATC is not, and
never has been, a party to any labor or other  collective  bargaining  agreement
with respect to any of the ATC Employees,  (b) there are no pending  grievances,
disputes or  controversies  with any union or any other  employee or  collective
bargaining organization of such employees, or threats of strikes, work stoppages
or slowdowns or any pending demands for collective  bargaining by any such union
or other  organization,  (c)  neither ATC nor any of such  employees  is now, or
since  January  1,  1995  has  been,  subject  to or  involved  in or,  to ATC's
knowledge,  threatened  with, any union elections,  petitions  therefor or other
organizational  or recruiting  activities,  in each case with respect to the ATC
Employees,  and (d) none of the ATC  Employees  has  notified ATC that he or she
does not intend to  continue  employment  with ATC until the Closing or with ATS
following  the  Closing.   ATC  has  performed  in  all  material  respects  all
obligations  required to be performed  under all Employment  Arrangements of ATC
and is not in material breach or violation of or in material  default or arrears
under any of the terms, provisions or conditions thereof.

         4.15 Material Agreements.  Listed on Section 4.15 of the ATC Disclosure
Schedule are all Material  Agreements  relating to the ownership or operation of
the ATC Assets or the conduct of the ATC  Business or to which ATC is a party or
to which it is bound or which any of the ATC Assets is subject.  True,  accurate
and complete copies of each of such Material Agreements have been made available
by ATC to ATS. All of such Material  Agreements  are valid,  binding and legally
enforceable  obligations of ATC, except as such enforceability may be limited by
bankruptcy,  moratorium,  insolvency  and similar laws  affecting the rights and
remedies  of  creditors  and  obligations  of debtors  generally  and by general
principles  of  equity.  ATC has  complied  with all of the  material  terms and
conditions  of each such Material  Agreement  and has not done or

                                      -13-


<PAGE>

performed,  or failed  to do or  perform  (and  there is no  pending  or, to the
knowledge  of  ATC,  threatened  in  writing  Claim  with  which  ATC has not so
complied,  done and  performed  or failed to do and perform) any act which would
invalidate or provide  grounds for the other party thereto to terminate (with or
without notice,  passage of time or both) such Material  Agreement or impair the
rights or  benefits,  or increase the costs,  of ATC under any of such  Material
Agreements, except for such noncompliances, acts or omissions that, individually
or in the aggregate, have not had and will not have a Material Adverse Effect on
ATC. Without  limiting the generality of the foregoing,  Section 4.15 of the ATC
Disclosure  Schedule sets forth a true, correct and complete  description of all
material  acquisitions  pending or which are actively  being  negotiated and the
current  status of all such  acquisitions,  except  for those  which ATC  cannot
disclose  due to its  obligations  to maintain the same in  confidence,  none of
which, if consummated on the terms and conditions  currently  being  negotiated,
will have a Material Adverse Effect on ATC.

         4.16 Ordinary Course of Business.  Since September 30, 1997, except (i)
as may be described on Section 4.16 of the ATC Disclosure  Schedule,  or (ii) as
may be required or  expressly  permitted  or  contemplated  by the terms of this
Agreement, ATC:

                  (a) has operated its business in all material  respects in the
         normal,  usual and customary  manner in the ordinary and regular course
         of business,  consistent with past practice,  it being  understood that
         the  acquisition  and  financing  of  communications  sites and related
         assets and other business involved in the communications sites industry
         and the  construction  of  communications  towers and related assets is
         part of the ordinary course of business of ATC;

                  (b) except in each case in the  ordinary  course of  business,
         consistent with past practice, it being understood that the acquisition
         and  financing  of  communications  sites and related  assets and other
         business  involved  in  the  communications   sites  industry  and  the
         construction of communications towers and related assets is part of the
         ordinary course of business of ATC:

                           (i) has not  incurred  any  obligation  or  liability
                  (fixed,  contingent or other)  individually  having a value in
                  excess of $100,000;

                           (ii)  has  not  sold  or  otherwise  disposed  of  or
                  contracted  to  sell  or  otherwise  dispose  of  any  of  its
                  properties or assets having a value in excess of $100,000;

                           (iii) has not entered into any individual  commitment
                  having a value in excess of $100,000; and

                           (iv) has not canceled any debts or claims;

                  (c) has not created or permitted to be created any Lien on any
         of its property, except for Permitted Liens;

                  (d) has not made or  committed  to make any  additions  to its
         property or any purchases of equipment,  except in the ordinary  course
         of business consistent with past practice or for normal maintenance and
         replacements;

                  (e) except in the ordinary course of business  consistent with
         past practice,  has not increased the compensation payable or to become
         payable to any of the ATC  Employees or otherwise  materially  altered,
         modified or changed the terms of their employment;

                                      -14-


<PAGE>


                  (f) has not suffered any damage,  destruction or loss (whether
         or not covered by insurance) or any  acquisition  or taking of property
         by any  Authority  that  has  had or is  reasonably  likely  to  have a
         Material Adverse Effect on ATC;

                  (g) has not waived any rights of material  value  without fair
         and adequate consideration;

                  (h) has not experienced any work stoppage;

                  (i) except in the ordinary course of business, has not entered
         into,  amended or  terminated  any Lease,  Governmental  Authorization,
         Private Authorization, Material Agreement or Employment Arrangement, or
         any  transaction,  agreement or arrangement  with any Affiliate of ATC;
         and

                  (j) has not made, paid or declared any Distribution.

         4.17  Material  and  Adverse  Restrictions.  ATC is not a  party  to or
subject  to,  nor is any of the ATC  Assets  subject  to,  any  Applicable  Law,
Governmental  Authorization,  Contractual  Obligation,  Employment  Arrangement,
Material  Agreement  or  Private  Authorization,  or  any  other  obligation  or
restriction  of any kind or  character,  which now has or, as far as ATC can now
reasonably foresee, at any time in the future, individually or in the aggregate,
is likely to have, any Material  Adverse  Effect on ATC,  except as set forth in
Section 4.17 of the ATC Disclosure Schedule and except for matters affecting the
tower rental and construction industry generally.

         4.18  Broker or Finder.  No Person  assisted  in or  brought  about the
negotiation of this Agreement or the Merger in the capacity of broker,  agent or
finder or in any similar  capacity on behalf of ATC or, to the knowledge of ATC,
any of the ATC stockholders  which, in any case, will result in liability to the
Surviving  Corporation  which was not  reflected  in the  financial  information
heretofore furnished by ATC to ATS.

         4.19 Solvency. As of the execution and delivery of this Agreement,  ATC
is, and immediately prior to the consummation of the Merger will be, Solvent.

         4.20 Environmental Matters.  Except as set forth in Section 4.20 of the
ATC  Disclosure  Schedule,  with respect to the ATC Assets and the ATC Business,
ATC:

                  (a) has not been notified that it is potentially liable under,
         has not received any request for  information  or other  correspondence
         concerning its potential liability with respect to any site or facility
         under,  and,  to ATC's  knowledge,  is not a  "potentially  responsible
         party" under, the Comprehensive  Environmental  Response,  Compensation
         and  Liability  Act of 1980,  as  amended,  the  Resource  Conservation
         Recovery Act, as amended, or any similar state law;

                  (b) has not  entered  into or  received  any  consent  decree,
         compliance  order  or  administrative  order  issued  pursuant  to  any
         Environmental Law;

                  (c) is  not a  party  in  interest  or in  default  under  any
         judgment,  order, writ,  injunction or decree of any Final Order issued
         pursuant to any Environmental Law;

                  (d) has  obtained all  Environmental  Permits  required  under
         Environmental  Laws, and has filed all applications,  notices and other
         documents  required to be filed prior to the date of this 

                                      -15-


<PAGE>

         Agreement to effect the timely renewal or issuance of all Environmental
         Permits  for the  continued  conduct of its  business in the manner now
         conducted;

                  (e)  is in  compliance  in  all  material  respects  with  all
         Environmental  Laws, and is not the subject of or, to ATC's  knowledge,
         threatened  with any Legal  Action  involving  a demand for  damages or
         other  potential  liability,   including  any  Lien,  with  respect  to
         violations or breaches of any Environmental Law;

                  (f) has  provided  ATS with copies of all  environmental  site
         assessments,  audits or other  investigatory  reports in its possession
         that  pertain to any  property  currently  owned,  leased,  operated or
         occupied by ATC;

                  (g) has not installed or used any above ground or  underground
         storage  tanks,  friable  asbestos,  polychlorinated  biphenyls or urea
         formaldehyde foam insulation on any property currently owned, leased or
         operated by ATC and, to ATC's  knowledge,  there are no above ground or
         underground storage tanks, friable asbestos,  polychlorinated biphenyls
         or urea formaldehyde  foam insulation or any property  currently owned,
         leased or operated by ATC;

                  (h) has not  disposed  of,  released,  spilled  or buried  any
         Hazardous  Materials  (nor has any Person acting on its behalf done so)
         in violation of  Environmental  Laws on any property or facility owned,
         leased,  operated  or  occupied  by ATC or to  ATC's  knowledge  at any
         facility or site to which Hazardous  Materials from or generated by ATC
         may have been taken at any time in the past;

                  (i) has no knowledge of any disposal, release, spill or burial
         of any Hazardous  Materials by ATC (or any Person acting on its behalf)
         on any  property  which could  reasonably  be expected to result or has
         resulted in contamination which requires investigation,  remediation or
         other  response  activity on or beneath any  properties  or  facilities
         currently owned, leased, operated or occupied by ATC; and

                  (j) has no knowledge of any past or present  Event  related to
         ATC's properties,  operations or business, which Event, individually or
         in the  aggregate,  could  reasonably be expected to interfere  with or
         prevent  continued  material  compliance  with all  Environmental  Laws
         applicable  to  the  conduct  of  ATC's  business  in  the  manner  now
         conducted, or which, individually or in the aggregate, could reasonably
         be  expected  to form the basis of any  material  Claim  against ATC in
         connection with the release or threatened  release into the environment
         of any Hazardous Material.

         4.21 Capital Stock. The authorized and outstanding capital stock of ATC
is as set forth in  Section  4.21 of the ATC  Disclosure  Schedule.  All of such
outstanding  capital stock has been duly authorized and validly issued, is fully
paid  and  nonassessable  and is  owned  of  record  and,  to  ATC's  knowledge,
beneficially as shown in Section 4.21 of the ATC Disclosure Schedule.  Except as
described in Section 4.21 of the ATC Disclosure Schedule, ATC has not granted or
issued, nor has ATC agreed to grant or issue, any shares of its capital stock or
any Option Security or Convertible Security,  and ATC is not a party to or bound
by any  agreement,  put or  commitment  pursuant  to  which it is  obligated  to
purchase,  redeem or otherwise acquire any shares of capital stock or any Option
Security  or  Convertible  Security.  The  affirmative  vote of the holders of a
majority of the shares of ATC Common Stock (the "ATC Required Vote") is the only
unobtained   vote  necessary  to  approve  and  adopt  this  Agreement  and  the
transactions  contemplated by this Agreement.  As of the date of this Agreement,
[e] votes  constituted  a majority of the  outstanding  voting  power of the ATC
Common Stock.

                                      -16-


<PAGE>



         4.22 State Takeover  Statutes.  To ATC's  knowledge,  no state takeover
Law,  statute or similar  statute or regulation  applies or purports to apply to
the Merger,  this  Agreement  or any of the  transactions  contemplated  by this
Agreement.



                                    ARTICLE 5

                      REPRESENTATIONS AND WARRANTIES OF ATS

         ATS  hereby  represents  and  warrants  to ATC  as  follows  (it  being
understood  and agreed by the  parties  that,  except as the  context  otherwise
requires,  the  representations  and warranties of ATS set forth in this Article
shall apply to each of its Subsidiaries with the same force and effect as though
each of them were named in each Section hereof):

         5.1  Organization  and  Business;   Power  and  Authority;   Effect  of
Transaction.

                  (a) ATS is a corporation duly organized,  validly existing and
         in good standing under the laws of its  jurisdiction  of  organization,
         has all requisite  power and authority  (corporate and other) to own or
         hold under  lease its  properties  and to conduct  its  business as now
         conducted  and is duly  qualified  and in good  standing  as a  foreign
         corporation  in each other  jurisdiction  in which the character of the
         property  owned  or  leased  by it or the  nature  of its  business  or
         operations requires such qualification,  except for such qualifications
         the failure of which to obtain, individually or in the aggregate, would
         not have a Material Adverse Effect on ATS.

                  (b) ATS has all requisite  power and authority  (corporate and
         other) and has in full force and effect all Governmental Authorizations
         and  Private  Authorizations  necessary  to  enable it to  execute  and
         deliver,  and to perform its obligations under, this Agreement and each
         Collateral  Document executed or required to be executed by it pursuant
         hereto or thereto and to consummate the  Transactions to which ATS is a
         party;  and the execution,  delivery and  performance of this Agreement
         and each Collateral  Document executed or required to be executed by it
         pursuant  hereto or thereto have been duly  authorized by all requisite
         corporate  or  other  action  on the  part  of ATS,  including  without
         limitation by the requisite approval of ARS, as the sole stockholder of
         ATS,  and no  other  corporate  proceedings  on  the  part  of ATS  are
         necessary to authorize this Agreement or the transactions  contemplated
         hereby  or to  consummate  the  Merger  or the  other  transactions  so
         contemplated.  This  Agreement  has been duly executed and delivered by
         ATS and constitutes,  and each Collateral Document executed or required
         to be executed by it pursuant  hereto or thereto or to  consummate  the
         Transactions when executed and delivered by ATS will constitute, legal,
         valid and binding  obligations of ATS,  enforceable in accordance  with
         their respective terms, except as such enforceability may be subject to
         bankruptcy,   moratorium,  insolvency,   reorganization,   arrangement,
         voidable  preference,  fraudulent  conveyance  and other  similar  laws
         relating to or affecting the rights of creditors and except as the same
         may be subject to the effect of general principles of equity.

                  (c)  Except  as  set  forth  in  Section  5.1(c)  of  the  ATS
         Disclosure Schedule,  neither the execution and delivery by ATS of this
         Agreement  or  any  Collateral  Document  executed  or  required  to be
         executed by it pursuant hereto or thereto,  nor the consummation of the
         Transactions  by ATS, nor  compliance  with the terms,  conditions  and
         provisions hereof or thereof by ATS:


                                      -17-


<PAGE>

                           (i) will  conflict  with,  or  result  in a breach or
                  violation  of, or  constitute  a default  under,  any  Organic
                  Document of ATS or any Applicable  Law, or will conflict with,
                  or result in a breach or violation of, or constitute a default
                  under,  or  permit  the  acceleration  of  any  obligation  or
                  liability in, or but for any  requirement  of giving of notice
                  or passage of time or both  would  constitute  such a conflict
                  with,  breach or violation of, or default under, or permit any
                  such acceleration in, any Material Agreement of ATS; or

                           (ii)  will   require   ATS  to  make  or  obtain  any
                  Governmental  Authorization,  Governmental  Filing or  Private
                  Authorization  including  without  limitation  under  the FCA,
                  except as required by the Hart-Scott-Rodino Act and other than
                  any of the foregoing that have been obtained.

                  (d)  Except  as  set  forth  in  Section  5.1(d)  of  the  ATS
         Disclosure Schedule, ATS does not have any Subsidiaries,  each of which
         is (i) wholly-owned unless noted otherwise in Section 5.1(d) of the ATS
         Disclosure  Schedule,  (ii) an Entity which is duly organized,  validly
         existing and in good standing under the laws of the respective state of
         organization,  and  (iii)  duly  qualified  and in good  standing  as a
         foreign corporation or other Entity in each other jurisdiction in which
         the  character of the  property  owned or leased by it or the nature of
         its business or operations requires such qualification, with full power
         and authority  (corporate  and other) to carry on the business in which
         it is engaged,  except for such  qualifications the failure of which to
         obtain,  individually  or in the  aggregate,  would not have a Material
         Adverse  Effect on ATS. ATS owns,  directly or  indirectly,  all of the
         outstanding capital stock and equity interests of each Subsidiary, free
         and clear of all Liens  (except  for  Permitted  Liens or except as set
         forth on Section 5.1(d) of the ATS Disclosure  Schedule),  and all such
         stock or other equity  interests has been duly  authorized  and validly
         issued and is fully paid and  nonassessable.  There are no  outstanding
         Option   Securities  or  Convertible   Securities,   or  agreements  or
         understandings of any nature whatsoever, relating to the authorized and
         unissued  or  outstanding  capital  stock or  equity  interests  of any
         Subsidiary  of ATS,  except as set forth in  Section  5.1(d) of the ATS
         Disclosure  Schedule with respect to the  noncorporate  Subsidiaries of
         ATS.

         5.2 Financial and Other Information.  The financial  statements of ATS,
furnished  by ATS,  and  included  in the ATS  Information  Statement  (the "ATS
Financial  Statements"),  including  in each case the notes  thereto,  have been
prepared in accordance  with GAAP applied on a consistent  basis  throughout the
periods  covered  thereby,  except as otherwise noted therein or as set forth in
Section 5.2 of the ATS Disclosure  Schedule,  and fairly present in all material
respects the financial  condition and the results of operations and cash flow of
ATS, on the bases therein stated,  as of the respective  dates thereof,  and for
the  respective  periods  covered  thereby  subject,  in the  case of  unaudited
financial  statements,  to normal  nonmaterial  year-end audit  adjustments  and
accruals.

         5.3 Material Statements and Omissions;  Absence of Events.  Neither any
representation  or  warranty  made by ATS  contained  in this  Agreement  or any
certificate,  document or other instrument or other information  furnished or to
be  furnished  by ATS  pursuant  to the  provisions  hereof  (including  without
limitation  information  with respect to ATS included in the ATS  Prospectus and
the ATS  Registration  Statement)  nor the ATS  Disclosure  Schedule  or the ATS
Information  Statement  contains  or will  contain  any  untrue  statement  of a
material  fact or omits or will omit to state any material fact required to make
any statement  contained herein or therein,  in light of the circumstances under
which they were made, not misleading; provided, however, that to the extent that
any such  information  contains any financial  projections,  ATS  represents and
warrants  only that such  projections  have been  prepared  in good faith on the
basis of the 

                                      -18-


<PAGE>

ATS  Financial  Statements  and  other  information  and  assumptions  which ATS
believes  to be  reasonable.  Since  the  date  of  the  most  recent  financial
statements  constituting a part of the ATS Financial  Statements,  except to the
extent  specifically  described in Section 5.3 of the ATS  Disclosure  Schedule,
there has been no change in ATS which has had a Material  Adverse Effect on ATS.
There  is no  Event  known  to ATS  which  has  had,  or (so  far as ATS can now
reasonably  foresee) is likely to have, a Material Adverse Effect on ATS, except
to the  extent  specifically  described  in  Section  5.3 of the ATS  Disclosure
Schedule  and except for  matters  affecting  the tower  rental,  ownership  and
construction  industry  generally,  including  without  limitation  competition,
regulation  and  resources  or events  arising  out of the  execution  or public
announcement of this Agreement.

         5.4 Title to Properties; Leases.

                  (a) ATS has, to ATS' knowledge, good and indefeasible title to
         all of its real property  (other than leasehold real property) and good
         title to all of its other assets (other than real  property),  tangible
         and intangible (the "ATS Assets");  all of such real property and other
         assets are so owned, in each case, free and clear of all Liens,  except
         (i) Permitted  Liens, and (ii) Liens set forth on Section 5.4(a) of the
         ATS Disclosure  Schedule.  Except for financing  statements  evidencing
         Liens referred to in the preceding  sentence,  no financing  statements
         under the Uniform  Commercial  Code and no other filing which names ATS
         as debtor or which covers or purports to cover any of the ATS Assets is
         on file in any state or other  jurisdiction,  and ATS has not signed or
         agreed to sign any such financing  statement or filing or any agreement
         authorizing  any secured party  thereunder  to file any such  financing
         statement or filing.  Except as disclosed in Section  5.4(a) of the ATS
         Disclosure  Schedule,  all  improvements  on the real property owned or
         leased by ATS are, to ATS'  knowledge,  in compliance  with  applicable
         zoning,  wetlands and land use laws,  ordinances  and  regulations  and
         applicable title covenants,  conditions,  restrictions and reservations
         in all  respects  necessary  to conduct  the  operations  as  presently
         conducted,  except for any instances of non-compliance which do not and
         will not in the aggregate have a Material Adverse Effect on ATS. Except
         as disclosed in Section  5.4(a) of the ATS  Disclosure  Statement,  all
         such  improvements  comply with all Applicable  Laws, ATS  Governmental
         Authorizations   and   ATS   Private   Authorizations,   except   where
         noncompliance  is not  reasonably  likely  to have a  Material  Adverse
         Effect on ATS. There is no pending or, to ATS' knowledge, threatened or
         contemplated  action to take by eminent  domain or otherwise to condemn
         any part of any real property  constituting  a material  portion of the
         real  property  owned by ATS or, to ATS'  knowledge,  any real property
         leased  by ATS.  Except  as set  forth  in  Section  5.4(a)  of the ATS
         Disclosure  Schedule,  such real property (other than land),  fixtures,
         fixed assets and other material items of personal  property,  including
         equipment,  have, in ATS' reasonable business judgment, been maintained
         in a manner consistent with customary  industry practices and currently
         permit the business of ATS (the "ATS  Business")  to be operated in all
         material  respects in accordance  with the terms and  conditions of all
         Applicable  Laws,  ATS  Governmental  Authorizations  and  ATS  Private
         Authorizations.

                  (b) Each Lease or other  occupancy  or other  agreement  under
         which ATS holds real or personal  property  constituting  a part of the
         ATS Assets  has been duly  authorized,  executed  and  delivered  by or
         assigned  to ATS and,  to ATS'  knowledge,  each of the  other  parties
         thereto,  and is a legal,  valid and binding obligation of ATS, and, to
         ATS'  knowledge,  each of the other  parties  thereto,  enforceable  in
         accordance with its terms, except as such enforceability may be limited
         by  bankruptcy,  moratorium,  insolvency and similar laws affecting the
         rights and remedies of creditors and  obligations of debtors  generally
         and by general principles of equity , and except for such exceptions to
         the foregoing as,  individually  or in the aggregate,  have not had and
         will not have  any  Material  Adverse

                                      -19-


<PAGE>

         Effect  on ATS.  ATS  has a  valid  leasehold  interest  in and  enjoys
         peaceful and undisturbed  possession under all Leases pursuant to which
         it holds any such real property or tangible personal property,  subject
         to the terms of each such Lease and  Applicable Law and except for such
         exceptions to the foregoing as, individually or in the aggregate,  have
         not had and will not have any  Material  Adverse  Effect on ATS. All of
         such Leases are valid and subsisting and in full force and effect,  and
         neither ATS nor, to ATS'  knowledge,  any other  party  thereto,  is in
         material default in the  performance,  observance or fulfillment of any
         obligation,  covenant or condition  contained in any such Lease, except
         for  such  exceptions  to  the  foregoing  as,  individually  or in the
         aggregate,  have not had and will not have any Material  Adverse Effect
         on ATS.

         5.5  Compliance  with  Private  Authorizations.  ATS has  obtained  all
Private Authorizations  (collectively,  the "ATS Private  Authorizations") which
are necessary for the ownership or operation of the ATS Assets or the conduct of
the ATS Business which, if not obtained and maintained,  could,  individually or
in the aggregate, be reasonably likely to have a Material Adverse Effect on ATS.
All of the ATS Private  Authorizations are valid and in good standing and are in
full force and effect,  except for such exceptions as are not reasonably  likely
to have a Material  Adverse Effect on ATS. ATS is not in breach or violation of,
or in default in the performance,  observance or fulfillment of, any ATS Private
Authorization,  and no Event exists or has occurred,  which constitutes,  or but
for any  requirement  of  giving  of notice  or  passage  of time or both  would
constitute,  such  a  breach,  violation  or  default,  under  any  ATS  Private
Authorization,  except for such  defaults,  breaches or violations as do not and
are not reasonably  likely to have in the aggregate a Material Adverse Effect on
ATS.  No ATS  Private  Authorization  is the  subject of any pending or, to ATS'
knowledge,  threatened  attack,  revocation  or  termination,  except  for  such
exceptions as are not  reasonably  likely to have a Material  Adverse  Effect on
ATS.

         5.6 Compliance with Governmental Authorizations and Applicable Law.

                  (a)  ATS  has   obtained   all   Governmental   Authorizations
         (collectively,   the  "ATS  Governmental   Authorizations")  which  are
         necessary  for the  ownership  or  operation  of the ATS  Assets or the
         conduct of the ATS Business as now conducted and which, if not obtained
         and  maintained,  would,  individually  or in the  aggregate,  have any
         Material   Adverse  Effect  on  ATS.  None  of  the  ATS   Governmental
         Authorizations  is subject to any  restriction or condition which would
         limit in a material  respect the  ownership  or  operations  of the ATS
         Assets or the  conduct  of the ATS  Business  as  currently  conducted,
         except for  restrictions  and  conditions  generally  applicable to ATS
         Governmental   Authorizations   of  such  type.  The  ATS  Governmental
         Authorizations  are valid and in good  standing,  are in full force and
         effect  and  are not  impaired  by any  act or  omission  of ATS or its
         officers,  directors,   employees  or  agents,  and  the  ownership  or
         operation  of the ATS Assets or the conduct of the ATS  Business are in
         accordance with the ATS  Governmental  Authorizations,  except for such
         exceptions to the foregoing as, individually or in the aggregate,  have
         not had and will  not have any  Material  Adverse  Effect  on ATS.  All
         material reports, forms and statements required to be filed by ATS with
         all  Authorities  with respect to the ATS Business  have been filed and
         are true,  complete  and  accurate  in all  material  respects.  No ATS
         Governmental  Authorization  is the  subject of any pending or, to ATS'
         knowledge,  threatened  challenge or  proceeding to revoke or terminate
         any ATS  Governmental  Authorization  which,  if revoked or terminated,
         would have a Material Adverse Effect on ATS.

                  (b) ATS is in  compliance  with all  Applicable  Laws,  except
         where such noncompliance, individually or in the aggregate, has not had
         and is not  reasonably  like to have a Material  Adverse Effect on ATS.
         Except as set forth in Section 5.6(b) of the ATS  Disclosure  Schedule,
         there are no 

                                      -20-

<PAGE>

         5.7  Intangible  Assets.  Except as set forth in Section 5.7 of the ATS
Disclosure   Schedule,   no   Intangible   Assets   (except   ATS   Governmental
Authorizations and ATS Private Authorizations) are required for the ownership or
operation  of the ATS Assets or the  conduct of the ATS  Business  as  currently
owned,  operated and conducted,  except for such exceptions to the foregoing as,
individually  or in the  aggregate,  have not had and will not have any Material
Adverse Effect on ATS. ATS does not, to its knowledge,  wrongfully infringe upon
or unlawfully use any Intangible Assets owned or claimed by another, and ATS has
not  received  any  notice of any  claim or  infringement  relating  to any such
Intangible Asset,  except for such exceptions to the foregoing as,  individually
or in the aggregate,  have not had and will not have any Material Adverse Effect
on ATS.

         5.8 Related Transactions. ATS is not a party or subject to any material
Contractual  Obligation relating to the ownership or operation of the ATS Assets
or the  conduct  of the  ATS  Business  between  ATS  and  any of its  officers,
directors or  stockholders  or, to the  knowledge  of ATS, any  Affiliate of any
thereof,  including without limitation any Contractual  Obligation providing for
the  furnishing of services to or by,  providing  for rental of property,  real,
personal or mixed,  to or from,  or  providing  for the lending or  borrowing of
money to or from or otherwise  requiring  payments to or from,  any such Person,
other than (i)  Employment  Arrangements  listed or described in Section 5.13 of
the ATS Disclosure Schedule, (ii) Contractual Obligations between ATS and any of
its  directors,  stockholders  or  officers  or  any  Affiliate  of  any  of the
foregoing, which are on arms' length terms and conditions, (iii) as specifically
set forth in Section 5.8 of the ATS Disclosure Schedule; provided, however, that
the foregoing representation and warranty shall not apply to the fact that prior
to  the  consummation  of  the  CBS  Merger,  all  administrative,   accounting,
corporate, data processing and other informational,  financial,  human resources
services, legal and other support services will have been provided by ARS to ATS
and  without  which  services  ATS could not operate in the  ordinary  course of
business.  Following  consummation  of the Merger,  a  sufficient  number of the
individuals  presently  providing  such  services  to ATS on  behalf of ARS will
continue to be available to provide  services  consistent  with past practice to
ATS so that ATS will be able to operate in the ordinary course of business.

         5.9 Insurance.  ATS  maintains,  with respect to the ATS Assets and the
ATS Business, policies of fire and extended coverage and casualty, liability and
other forms of  insurance  in such  amounts and against such risks and losses as
are customary for companies engaged in similar businesses.

         5.10 Tax Matters.

                  (a) ATS has in accordance  with all Applicable  Laws filed all
         Tax  Returns  which are  required  to be filed,  and has paid,  or made
         adequate  provision for the payment of, all Taxes which have become due
         and payable  pursuant  to said Tax  Returns and all other  governmental
         charges and  assessments  received to date other than those Taxes being
         contested in good faith for which  adequate  provision has been made on
         the most recent balance sheet forming part of ATS Financial Statements.
         The Tax Returns of ATS have been  prepared in all material  respects in
         accordance with all Applicable Laws. All Taxes which ATS is required by
         law to withhold and collect have been duly withheld and collected,  and
         have been paid over, in a timely manner,  to the proper  Authorities to
         the extent due and payable.  ATS has not executed any waiver to extend,
         or  otherwise  taken or failed to take any  action  that would have the
         effect of extending,  the applicable  statute of limitations in respect
         of any Tax  liabilities  of ATS  for  the  fiscal  years  prior  to and
         including  the  most  recent  fiscal  year.  ATS is  not a  "consenting
         corporation"  within the meaning of Section 341(f) of the Code.

                                      -21-


<PAGE>

         ATS has at all times been taxable as a Subchapter C  corporation  under
         the Code, and has never been a member of any consolidated group for Tax
         purposes, except as a member of the consolidated group with ARS and all
         of its  Subsidiaries  which can be consolidated  for Federal income tax
         purposes.

                  (b) Federal and state  income Tax Returns of ATS have not been
         examined by the IRS or applicable state Authority, and ATS has not been
         notified  of any  proposed  examination,  except  as shown  in  Section
         5.10(b) of the ATS Disclosure Schedule.

                  (c)  ATS is  not a  party  to any  tax  sharing  agreement  or
         arrangement  with any other  Person,  except  as set  forth in  Section
         5.10(c) of the ATS Disclosure Schedule.

         5.11 Employee Retirement Income Security Act of 1974.

                  (a) ATS (which for purposes of this Section  shall include any
         ERISA Affiliate of ATS) currently  sponsors,  maintains and contributes
         only to the Plans and Benefit Arrangements set forth in Section 5.11(a)
         of the ATS Disclosure Schedule.  ATS has delivered or made available to
         ATC true,  complete  and  correct  copies of (i) each Plan and  Benefit
         Arrangement  (or,  in  the  case  of any  unwritten  Plans  or  Benefit
         Arrangements,  reasonable  descriptions  thereof),  (ii)  the two  most
         recent  annual  reports  on Form  5500  (including  all  schedules  and
         attachments  thereto)  filed with the  Internal  Revenue  Service  with
         respect to each Plan (if any such  report was  required  by  Applicable
         Law),  (iii) the most  recent  summary  plan  description  (or  similar
         document)  for each Plan for which such a summary plan  description  is
         required  by  Applicable   Law  or  was  otherwise   provided  to  plan
         participants  or  beneficiaries,  and (iv)  each  trust  agreement  and
         insurance or annuity contract or other funding or financing arrangement
         relating to any Plan.  To the knowledge of ATS, each such Form 5500 and
         each such summary plan  description (or similar  document) does not, as
         of the date hereof,  contain any material  misstatements.  ATS does not
         contribute to or have an  obligation  to contribute  to, and has not at
         any time  within  six (6)  years  prior  to the date of this  Agreement
         contributed  to or had an  obligation  to  contribute  to,  and no Plan
         listed in Section  5.11(a)  of the ATS  Disclosure  Schedule  is, (i) a
         Multiemployer  Plan, or (ii) a Plan subject to Section 412 of the Code,
         Section  302 of  ERISA  or  Title IV of  ERISA.  ATS has no  actual  or
         potential  liability under Title IV of ERISA. ATS does not maintain any
         Plan  that  provides  for  post-retirement  medical  or life  insurance
         benefits,  and ATS  does  not have any  obligation  or  liability  with
         respect to any such Plan  previously  maintained by ATS,  except as the
         provisions of COBRA may apply to any former employees of ATS. Except as
         set forth in Section 5.11(a) of the ATS Disclosure Schedule,  as to all
         Plans and  Benefit  Arrangements  listed in Section  5.11(a) of the ATS
         Disclosure Schedule:

                           (i) all such Plans and  Benefit  Arrangements  comply
                  and  have  been  administered  in  form  and in  operation  in
                  accordance  with  their   respective   terms,   and  with  all
                  Applicable  Laws,  in all material  respects,  and ATS has not
                  received   any  notice  from  any   Authority   disputing   or
                  investigating such compliance;

                           (ii) none of the assets of any such Plan are invested
                  in employer securities or employer real property;

                           (iii) there are no Claims (other than routine  Claims
                  for benefits or actions seeking qualified  domestic  relations
                  orders)  pending or, to ATS' knowledge,  threatened  involving
                  such  Plans  or  the  assets  of  such  Plans,  and,  to  ATS'
                  knowledge,  no facts exist which are

                                      -22-


<PAGE>

                  reasonably  likely to give rise to any such Claims (other than
                  routine  Claims  for  benefits  or actions  seeking  qualified
                  domestic relations orders);

                           (iv) all  material  contributions  to,  and  material
                  payments  from,  the Plans and Benefit  Arrangements  that may
                  have been required to be made in accordance  with the terms of
                  the  Plans  and  Benefit  Arrangements,   and  any  applicable
                  collective  bargaining  agreement,  have been  made.  All such
                  contributions  to, and  payments  from,  the Plans and Benefit
                  Arrangements,  except  those  payments to be made from a trust
                  qualified  under  Section  401(a) of the Code,  for any period
                  ending  before the Closing Date that are not yet, but will be,
                  required to be made, will be properly accrued and reflected on
                  the financial books and records of ATS;

                           (v) No act,  omission  or  transaction  has  occurred
                  which would result in  imposition  on ATS of (A) any breach of
                  fiduciary duty  liability  damages under Section 409 of ERISA,
                  (B) a civil penalty assessed  pursuant to subsections (c), (i)
                  or (l) of Section 502 of ERISA or (C) a tax  imposed  pursuant
                  to Chapter 43 of Subtitle D of the Code;

                           (vi) ATS has not incurred any material liability to a
                  Plan  (other  than  for   contributions  not  yet  due)  which
                  liability has not been fully paid or accrued for payment as of
                  the date hereof;

                           (vii)  except  as  otherwise   contemplated  by  this
                  Agreement or the ATS Disclosure Schedule, no current or former
                  employee of ATS will be entitled to any additional benefits or
                  any  acceleration  of the time of  payment  or  vesting of any
                  benefits under any Plan or Benefit  Arrangement as a result of
                  the transactions contemplated by this Agreement;

                           (viii) no  compensation  payable by ATS to any of its
                  employees  under  any  existing  Plan,   Benefit   Arrangement
                  (including by reason of the transactions  contemplated hereby)
                  will be subject to  disallowance  under Section  162(m) of the
                  Code;

                           (ix) any amount  that could be  received  (whether in
                  cash or property or the  vesting of  property)  as a result of
                  any of the transactions  contemplated by this Agreement by any
                  employee,  officer,  director or independent contractor of ATS
                  who is a "disqualified individual" (as such term is defined in
                  proposed  Treasury  Regulation  Section  1.280G-1)  under  any
                  employment  arrangement  would  not  be  characterized  as  an
                  "excess parachute payment" (as such term is defined in Section
                  280G(b)(1) of the Code),;

                           (x)  all  such  Plans  maintained  by  ATS  that  are
                  intended  to  comply  with  Sections  401 and 501 of the  Code
                  comply  in  all   material   respects   with  all   applicable
                  requirements of such sections, and no Event has occurred which
                  is known to ATS which  will give rise to  disqualification  of
                  any such Plan under such  sections  or to a tax under  Section
                  511 of the Code and each such Plan has been the  subject  of a
                  determination  letter from the Internal Revenue Service to the
                  effect  that  such Plan and  related  trust is  qualified  and
                  exempt from  Federal  income Taxes under  Sections  401(a) and
                  501(a),  respectively,  of the  Code;  no  such  determination
                  letter  has  been  revoked,  and,  to the  knowledge  of  ATS,
                  revocation has not been threatened.  ATS has delivered or made
                  available  to ATC a  copy  of the  most  recent  determination
                  letter  received  with  respect  to each Plan for which such a
                  letter  has  been  issued,  as well  as a copy of any  pending
                  application for a determination  letter. ATS has also 

                                      -23-


<PAGE>

                  provided  or  made  available  to  ATC  a  list  of  all  Plan
                  amendments  as to which a favorable  determination  letter has
                  not yet been received;

                           (xi) no Plan  which is an  employee  stock  ownership
                  plan  (an  "ESOP")  constitutes  a  leveraged  employee  stock
                  ownership plan within the meaning of Section 4975(e)(7) of the
                  Code  and  there  are no  unallocated  shares  of stock of ATS
                  currently held under any such ESOP in a suspense account; and

                           (xii)   there   are  no   outstanding   options   (or
                  contractual  obligations  to issue  options)  to  acquire  ATS
                  Common Stock or other ATS  securities  other than options held
                  by employees  or  directors  of ATS and issued  under  Benefit
                  Arrangements  (the aggregate  number of which are as set forth
                  in Section 5.11(a) of the ATS Disclosure Schedule).

                  (b) The  execution,  delivery and  performance  by ATS of this
         Agreement  and the  Collateral  Documents  executed  or  required to be
         executed  by ATS  pursuant  hereto and  thereto  will not  involve  any
         prohibited  transaction  within the meaning of ERISA or Section 4975 of
         the Code with respect to any Plan listed in Section  5.11(a) of the ATS
         Disclosure Schedule.

         5.12 Absence of Sensitive Payments. Neither ATS nor, to ATS' knowledge,
any of its officers, directors, employees, agents or other representatives,  has
with respect to the ATS Assets or the ATS  Business (a) made any  contributions,
payments  or  gifts  to or for the  private  use of any  governmental  official,
employee or agent where either the payment or the purpose of such  contribution,
payment  or  gift  is  illegal  under  the  laws  of the  United  States  or the
jurisdiction  in which made or (b) established or maintained any unrecorded fund
or asset for any illegal purpose or made any false or artificial  entries on its
books.

         5.13  Employment  Arrangements.  ATS has no  obligation  or  liability,
contingent or other,  under any Employment  Arrangement with any employee of ATS
or any of its Subsidiaries (the "ATS Employees"), other than (i) those listed or
described  in Section  5.11(a) or Section 5.13 of the ATS  Disclosure  Schedule,
(ii) those incurred in the ordinary and usual course of business,  or (iii) such
obligations or  liabilities  as do not and will not have, in the aggregate,  any
Material  Adverse Effect on ATS.  Except as described in Section 5.13 of the ATS
Disclosure  Schedule,  (a)  none  of the ATS  Employees  is now,  or  since  its
organization  has  been,  represented  by any  labor  union  or  other  employee
collective bargaining organization,  and ATS is not, and never has been, a party
to any labor or other collective bargaining agreement with respect to any of the
ATS Employees,  (b) there are no pending  grievances,  disputes or controversies
with any union or any other employee or collective  bargaining  organization  of
such employees, or threat of strikes, work stoppages or slowdowns or any pending
demands for collective  bargaining by any such union or other organization,  (c)
neither  ATS nor any of such  employees  is now, or since its  organization  has
been,  subject to or involved in or, to ATS'  knowledge,  threatened  with,  any
union  elections,  petitions  therefor  or other  organizational  or  recruiting
activities,  in each case with respect to the ATS Employees, and (d) none of the
ATS  Employees  has  notified  ATS that he or she does not  intend  to  continue
employment with ATS until the Closing or with ATS following the Closing. ATS has
performed in all  material  respects  all  obligations  required to be performed
under  all  Employment  Arrangements  of ATS and is not in  material  breach  or
violation  of or in  material  default  or  arrears  under  any  of  the  terms,
provisions or conditions thereof.

         5.14 Material Agreements.  Listed on Section 5.14 of the ATS Disclosure
Schedule are all Material  Agreements  relating to the ownership or operation of
the ATS Assets or the conduct of the ATS  Business or to which ATS is a party or
to which it is bound or which any of the ATS Assets is subject.  True,  accurate
and complete copies of each of such Material Agreements have been made available
by ATS to ATC. All of such 

                                      -24-


<PAGE>


Material Agreements are valid,  binding and legally  enforceable  obligations of
ATS,  except as such  enforceability  may be limited by bankruptcy,  moratorium,
insolvency  and similar laws  affecting the rights and remedies of creditors and
obligations of debtors  generally and by general  principles of equity.  ATS has
complied  with all of the material  terms and  conditions  of each such Material
Agreement and has not done or  performed,  or failed to do or perform (and there
is no pending or, to the  knowledge  of ATS,  threatened  in writing  Claim with
which ATS has not so complied,  done and  performed or failed to do and perform)
any act which would invalidate or provide grounds for the other party thereto to
terminate  (with or  without  notice,  passage  of time or both)  such  Material
Agreement or impair the rights or benefits,  or increase the costs, of ATS under
any of  such  Material  Agreements,  except  for  such  noncompliances,  acts or
omissions that, individually or in the aggregate, have not had and will not have
a  Material  Adverse  Effect on ATS.  Without  limiting  the  generality  of the
foregoing,  Section  5.14  of the ATS  Disclosure  Schedule  sets  forth a true,
correct and complete  description of all material  acquisitions pending or which
are actively being  negotiated and the current status of all such  acquisitions,
except for those which ATS cannot  disclose due to its  obligations  to maintain
the  same  in  confidence,  none of  which,  if  consummated  on the  terms  and
conditions  currently being  negotiated,  will have a Material Adverse Effect on
ATS.

         5.15 Ordinary Course of Business.  Since September 30, 1997, except (i)
as may be described on Section 5.15 of the ATS Disclosure  Schedule,  or (ii) as
may be required or  expressly  permitted  or  contemplated  by the terms of this
Agreement, ATS:

                  (a) has operated its business in all material  respects in the
         normal,  usual and customary  manner in the ordinary and regular course
         of business,  consistent with past practice,  it being  understood that
         the  acquisition  and  financing  of  communications  sites and related
         assets and other business involved in the communications sites industry
         and the  construction  of  communications  towers and related assets is
         part of the ordinary course of business of ATS;

                  (b) except in each case in the  ordinary  course of  business,
         consistent with past practice, it being understood that the acquisition
         and  financing  of  communications  sites and related  assets and other
         business  involved  in  the  communications   sites  industry  and  the
         construction of communications towers and related assets is part of the
         ordinary course of business of ATS:

                           (i) has not  incurred  any  obligation  or  liability
                  (fixed,  contingent or other)  individually  having a value in
                  excess of $100,000;

                           (ii)  has  not  sold  or  otherwise  disposed  of  or
                  contracted  to  sell  or  otherwise  dispose  of  any  of  its
                  properties or assets having a value in excess of $100,000;

                           (iii) has not entered into any individual  commitment
                  having a value in excess of $100,000; and

                           (iv) has not canceled any debts or claims;

                  (c) has not created or permitted to be created any Lien on any
         of its property, except for Permitted Liens;

                  (d) has not made or  committed  to make any  additions  to its
         property or any purchases of equipment,  except in the ordinary  course
         of business consistent with past practice or for normal maintenance and
         replacements;

                                      -25-


<PAGE>


                  (e) except in the ordinary course of business  consistent with
         past practice,  has not increased the compensation payable or to become
         payable to any of the ATS  Employees or otherwise  materially  altered,
         modified or changed the terms of their employment;

                  (f) has not suffered any damage,  destruction or loss (whether
         or not covered by insurance) or any  acquisition  or taking of property
         by any  Authority  that  has  had or is  reasonably  likely  to  have a
         Material Adverse Effect on ATS;

                  (g) has not waived any rights of material  value  without fair
         and adequate consideration;

                  (h) has not experienced any work stoppage;

                  (i) except in the ordinary course of business, has not entered
         into,  amended or  terminated  any Lease,  Governmental  Authorization,
         Private Authorization, Material Agreement or Employment Arrangement, or
         any  transaction,  agreement or arrangement  with any Affiliate of ATS;
         and

                  (j) has not made, paid or declared any Distribution.

         5.16  Material  and  Adverse  Restrictions.  ATS is not a  party  to or
subject  to,  nor is any of the ATS  Assets  subject  to,  any  Applicable  Law,
Governmental  Authorization,  Contractual  Obligation,  Employment  Arrangement,
Material  Agreement  or  Private  Authorization,  or  any  other  obligation  or
restriction  of any kind or  character,  which now has or, as far as ATS can now
reasonably foresee, at any time in the future, individually or in the aggregate,
is likely to have, any Material  Adverse  Effect on ATS,  except as set forth in
Section 5.16 of the ATS Disclosure Schedule and except for matters affecting the
tower rental and construction industry generally.

         5.17  Broker or Finder.  No Person  assisted  in or  brought  about the
negotiation of this Agreement or the Merger in the capacity of broker,  agent or
finder or in any similar  capacity on behalf of ATS or, to the knowledge of ATS,
ARS which, in each case,  will result in liability to the Surviving  Corporation
which was not reflected in the financial information heretofore furnished by ATS
to ATC.

         5.18 Solvency. As of the execution and delivery of this Agreement,  ATS
is, and immediately prior to the consummation of the Merger will be, Solvent.

         5.19 Environmental Matters.  Except as set forth in Section 5.19 of the
ATS  Disclosure  Schedule,  with respect to the ATS Assets and the ATS Business,
ATS:

                  (a) has not been notified that it is potentially liable under,
         has not received any request for  information  or other  correspondence
         concerning its potential liability with respect to any site or facility
         under, and, to ATS' knowledge, is not a "potentially responsible party"
         under,  the  Comprehensive  Environmental  Response,  Compensation  and
         Liability Act of 1980, as amended, the Resource  Conservation  Recovery
         Act, as amended, or any similar state law;

                  (b) has not  entered  into or  received  any  consent  decree,
         compliance  order  or  administrative  order  issued  pursuant  to  any
         Environmental Law;


                                      -26-


<PAGE>


                  (c) is  not a  party  in  interest  or in  default  under  any
         judgment,  order, writ,  injunction or decree of any Final Order issued
         pursuant to any Environmental Law;

                  (d) has  obtained all  Environmental  Permits  required  under
         Environmental  Laws, and has filed all applications,  notices and other
         documents  required to be filed prior to the date of this  Agreement to
         effect the timely renewal or issuance of all Environmental  Permits for
         the continued conduct of its business in the manner now conducted;

                  (e)  is in  compliance  in  all  material  respects  with  all
         Environmental  Laws,  and is not the subject of or, to ATS'  knowledge,
         threatened  with any Legal  Action  involving  a demand for  damages or
         other  potential  liability,   including  any  Lien,  with  respect  to
         violations or breaches of any Environmental Law;

                  (f) has  provided  ATC with copies of all  environmental  site
         assessments,  audits or other  investigatory  reports in its possession
         that  pertain to any  property  currently  owned,  leased,  operated or
         occupied by ATS;

                  (g) has not installed or used any above ground or  underground
         storage  tanks,  friable  asbestos,  polychlorinated  biphenyls or urea
         formaldehyde foam insulation on any property currently owned, leased or
         operated by ATS and, to ATS'  knowledge,  there are no above  ground or
         underground storage tanks, friable asbestos,  polychlorinated biphenyls
         or urea formaldehyde  foam insulation or any property  currently owned,
         leased or operated by ATS;

                  (h) has not  disposed  of,  released,  spilled  or buried  any
         Hazardous  Materials  (nor has any Person acting on its behalf done so)
         in violation of  Environmental  Laws on any property or facility owned,
         leased,  operated  or  occupied  by ATS  or to  ATS'  knowledge  at any
         facility or site to which Hazardous  Materials from or generated by ATS
         may have been taken at any time in the past;

                  (i) has no knowledge of any disposal, release, spill or burial
         of any Hazardous  Materials by ATS (or any Person acting on its behalf)
         on any  property  which could  reasonably  be expected to result or has
         resulted in contamination which requires investigation,  remediation or
         other  response  activity on or beneath any  properties  or  facilities
         currently owned, leased, operated or occupied by ATS; and

                  (j) has no knowledge of any past or present  Event  related to
         ATS' properties,  operations or business, which Event,  individually or
         in the  aggregate,  could  reasonably be expected to interfere  with or
         prevent  continued  material  compliance  with all  Environmental  Laws
         applicable to the conduct of ATS' business in the manner now conducted,
         or  which,  individually  or in  the  aggregate,  could  reasonably  be
         expected  to form  the  basis  of any  material  Claim  against  ATS in
         connection with the release or threatened  release into the environment
         of any Hazardous Material.

         5.20 Capital Stock. The authorized and outstanding capital stock of ATS
is as set forth in  Section  5.20 of the ATS  Disclosure  Schedule.  All of such
outstanding  capital stock has been duly authorized and validly issued, is fully
paid  and  nonassessable  and  is  owned  of  record  and,  to  ATS'  knowledge,
beneficially  by ARS.  Except as described in Section 5.20 of the ATS Disclosure
Schedule,  ATS has not granted or issued,  nor has ATS agreed to grant or issue,
any shares of its capital stock or any Option Security or Convertible  Security,
and ATS is not a party to or bound by any agreement,  put or commitment pursuant
to which it is obligated to purchase,  redeem or otherwise acquire any shares of
capital stock or any Option Security or 

                                      -27-


<PAGE>


Convertible  Security.  The  shares  of ATS  Class A Common  Stock to be  issued
pursuant to  consummation of the Merger or upon exercise of the ATS Options have
been duly authorized and, when so issued, will be validly issued, fully paid and
nonassumable,  and all such shares have been duly reserved for issuance pursuant
to such consummation or exercise.

         5.21 State Takeover Statutes. To ATS' knowledge, no state takeover Law,
statute or similar  statute or  regulation  applies or  purports to apply to the
Merger,  this  Agreement  or  any  of  the  transactions  contemplated  by  this
Agreement.

         5.22  ATS  Private  Placement.  ATS and the  Persons  named  in the ATS
Information  Statement (and possible other Persons) intend to enter into binding
and definitive documentation substantially on the terms and conditions described
in the ATS  Information  Statement  with  respect to the ATS Private  Placement.
Pursuant  to such  documentation,  ATS and such  Persons  will  have  agreed  to
purchase  shares of ATS Class B Common Stock for a per share  purchase  price of
not less than $9.00 per share and for an aggregate  purchase  price equal to not
less than $80.0 million on such other terms and conditions  not materially  less
favorable,  in the aggregate, to ATS than those described in the ATS Information
Statement.

         5.23 ARS  Organization  and Business;  Power and  Authority;  Effect of
Transaction.

                  (a) ARS is a corporation duly organized,  validly existing and
         in good standing under the laws of its  jurisdiction  of  organization,
         has all requisite  power and authority  (corporate and other) to own or
         hold under  lease its  properties  and to conduct  its  business as now
         conducted  and is duly  qualified  and in good  standing  as a  foreign
         corporation  in each other  jurisdiction  in which the character of the
         property  owned  or  leased  by it or the  nature  of its  business  or
         operations requires such qualification,  except for such qualifications
         the failure of which to obtain, individually or in the aggregate, would
         not have a Material Adverse Effect on ARS.

                  (b) ARS has all requisite  power and authority  (corporate and
         other) and has in full force and effect all Governmental Authorizations
         and  Private  Authorizations  necessary  to  enable it to  execute  and
         deliver, and to perform its obligations under, the CBS Merger Agreement
         and each  agreement  or  other  document  executed  or  required  to be
         executed by it pursuant thereto,  including without  limitation the ATS
         Separation  Agreement,  and to consummate  the CBS Merger and the Tower
         Distribution;  and the execution,  delivery and  performance of the CBS
         Merger  Agreement  and each  agreement  or other  document  executed or
         required to be  executed by ARS  pursuant  thereto,  including  without
         limitation the ATS Separation  Agreement,  have been duly authorized by
         all  requisite  corporate  or other  action on the part of ARS,  and no
         other  corporate  proceedings  on the  part of ARS,  including  without
         limitation  that of the  ARS  common  stockholders,  are  necessary  to
         authorize  the CBS Merger  Agreement or the  transactions  contemplated
         thereby,  including without limitation the ATS Separation Agreement, or
         to consummate the CBS Merger and the Tower Distribution. The CBS Merger
         Agreement has been duly executed and delivered by ARS and  constitutes,
         and each  agreement  or  other  document  executed  or  required  to be
         executed by it pursuant thereto or to consummate the CBS Merger and the
         Tower Distribution, when executed and delivered by ARS will constitute,
         legal, valid and binding obligations of ARS,  enforceable in accordance
         with  their  respective  terms,  except as such  enforceability  may be
         subject  to   bankruptcy,   moratorium,   insolvency,   reorganization,
         arrangement,  voidable  preference,  fraudulent  conveyance  and  other
         similar  laws  relating to or  affecting  the rights of  creditors  and
         except as the same may be subject  to the effect of general  principles
         of equity.  No  consent or  approval  from the  stockholders  of ARS is
         required to consummate the Merger (including the issuance of the Merger
         Consideration) or the Tower  Distribution,  except 

                                      -28-


<PAGE>

         that a waiver of the restricted payments covenant of the Certificate of
         Designation  with respect to the ARS  Cumulative  Preferred  Stock (the
         "ARS Preferred  Certificate") will be required from the holders thereof
         in order to effect the Tower Distribution,  whether pursuant to the CBS
         Merger Agreement or otherwise.

                  (c)  Except  as set  forth  in  Section  5.23(c)  of  the  ATS
         Disclosure  Schedule or in Section  5.23(b),  neither the execution and
         delivery by ARS of the CBS Merger  Agreement or any  agreement or other
         document  executed or  required to be executed by it pursuant  thereto,
         nor the  consummation  of the CBS Merger or the Tower  Distribution  by
         ARS, nor compliance with the terms, conditions and provisions hereof or
         thereof by ARS:

                           (i) will  conflict  with,  or  result  in a breach or
                  violation  of, or  constitute  a default  under,  any  Organic
                  Document of ARS or any Applicable  Law, or will conflict with,
                  or result in a breach or violation of, or constitute a default
                  under,  or  permit  the  acceleration  of  any  obligation  or
                  liability in, or but for any  requirement  of giving of notice
                  or passage of time or both  would  constitute  such a conflict
                  with,  breach or violation of, or default under, or permit any
                  such acceleration in, any Material Agreement of ARS; or

                           (ii)  will   require   ARS  to  make  or  obtain  any
                  Governmental  Authorization,  Governmental  Filing or  Private
                  Authorization  including  without  limitation  under  the FCA,
                  except as required by the Hart-Scott-Rodino Act and other than
                  any of the foregoing that have been obtained.

                                    ARTICLE 6

                                    COVENANTS

         6.1 Access to Information; Confidentiality.

                  (a)  Each  party  shall  afford  to the  other  party  and its
         accountants, counsel, financial advisors and other representatives (the
         "Representatives")  full access during normal business hours throughout
         the  period  prior  to  the  Closing  Date  to  all  of  its  (and  its
         Subsidiaries')  properties,  books, contracts,  commitments and records
         (including  without  limitation Tax Returns),  but excluding any of the
         foregoing  that are or may become the subject  of, and not  disclosable
         under,  the  terms  of  any  confidential  agreement  (the  "Restricted
         Information")  and,  during such period,  shall  furnish  promptly upon
         request (i) a copy of each report, schedule and other document filed or
         received by either party pursuant to the requirements of any Applicable
         Law  (including  without  limitation  the  FCA) or filed by it with any
         Authority in connection  with the Merger or any other report,  schedule
         or  documents  which  may have a  material  effect  on the  businesses,
         operations,  properties, prospects, personnel, condition, (financial or
         other), or results of operations of their respective  businesses,  (ii)
         to the extent not provided for pursuant to the  preceding  clause,  all
         financial records,  ledgers, work papers and other sources of financial
         information  possessed or controlled by it or its accountants deemed by
         each party or its  Representatives  necessary or useful for the purpose
         of  performing  an audit of the  business and assets of ATC and ATS, as
         applicable,  and, in the case of ATS, certifying  financial  statements
         and financial information pursuant to the provisions of Section 7.2(d),
         and (iii) such other information concerning any of the foregoing as ATS
         or ATC shall reasonably request, other than any Restricted Information.
         All Confidential  Information  furnished  pursuant to the provisions of
         this Agreement, including without limitation this Section, will be kept
         confidential  and shall not,  without the prior 

                                      -29-


<PAGE>

         written consent of the party disclosing such Confidential  Information,
         which  consent  shall  not  be   unreasonably   withheld,   delayed  or
         conditioned,  be disclosed by the other party in any manner whatsoever,
         in whole or in part,  and,  except as required by Applicable Law, shall
         not be used for any purposes,  other than in connection with the Merger
         (including  without  limitation  in connection  with any  registration,
         proxy or  information  statement or similar  document filed pursuant to
         any  federal  or state  securities  Law) . Except as  otherwise  herein
         provided,  each party  agrees to reveal such  Confidential  Information
         only to those of its  Representatives or other Persons who need to know
         such  Confidential  Information  for  the  purpose  of  evaluating  and
         consummating  the Merger who are informed of its  confidential  nature.
         For purposes of this Agreement,  "Confidential  Information" shall mean
         any and all information  (excluding information that (i) has been or is
         obtained from a source  independent of the disclosing party, (ii) is or
         becomes  generally  available  to the public  other than as a result of
         unauthorized   disclosure   by  the  receiving   party,   or  (iii)  is
         independently  developed by the receiving party without reliance in any
         way on  information  provided by the  disclosing  party) related to the
         business or businesses of ATS and its  Affiliates,  on the one hand, or
         ATC and its  Affiliates,  on the  other  hand,  including  any of their
         respective successors and assigns.

                  (b)  In  the  event  that  this  Agreement  is  terminated  in
         accordance  with its terms,  each party shall  promptly  redeliver  all
         written  Confidential  Information provided pursuant to this Section or
         any other  provision of this Agreement or otherwise in connection  with
         the  Merger  and  shall  not  retain  any  copies,  extracts  or  other
         reproductions in whole or in part of such written material, other than,
         in the event any Legal Action or Claim is then  pending,  threatened or
         reasonably  likely to be  asserted,  one copy  thereof  which  shall be
         delivered to independent counsel for such party.

                  (c) No  investigation  pursuant to this  Section or  otherwise
         shall affect any representation or warranty in this Agreement of either
         party or any condition to the obligations of the parties hereto.

                  (d)  The  provisions  of  this  Section  shall  apply  to  all
         Subsidiaries of ATC and ATS.

         6.2 Agreement to Cooperate.

                  (a) Each of the parties hereto shall use  reasonable  business
         efforts  (x) to take,  or cause to be taken,  all actions and to do, or
         cause to be done,  all  things  necessary,  proper or  advisable  under
         Applicable  Law to  consummate  the Merger  according  to the terms and
         subject to the conditions  hereof,  and (y) to refrain from taking,  or
         cause to be taken,  any action and to refrain  from doing or causing to
         be done,  anything which could impede or impair the consummation of the
         Merger  according to the terms and subject to the conditions  hereof or
         the consummation of the other  Transactions  according to the terms and
         subject to the  conditions  hereof,  including,  in all cases,  without
         limitation  using its  reasonable  business  efforts (i) to prepare and
         file with the applicable  Authorities as promptly as practicable  after
         the  execution  of  this  Agreement  all  requisite   applications  and
         amendments  thereto,  together  with  related  information,   data  and
         exhibits,  necessary to request issuance of orders approving the Merger
         by all such  applicable  Authorities,  (ii) to obtain all  necessary or
         appropriate  waivers,  consents  and  approvals,  (iii) to  effect  all
         necessary  registrations,  filings and submissions  (including  without
         limitation,  if required,  filings within ten (10) business days of the
         date of this Agreement under the  Hart-Scott-Rodino Act and all filings
         necessary  for  ATS to own  and  operate  the  ATC  Assets  and the ATC
         Business), (iv) to lift any injunction or other legal bar to the Merger
         (and,  in such case,  to proceed  with the Merger as  expeditiously  as
         possible),  and  (v) to  obtain  the  satisfaction  of  the  conditions
         specified  in Article 7,  including  without  limitation  the truth and
         correctness  as of the Closing Date as if made on and as of the Closing
         Date (other than those that 

                                      -30-


<PAGE>

         speak as of a specific  date which need only be true and  correct as of
         such date) of the  representations and warranties of such party and the
         performance  and  satisfaction as of the Closing Date of all agreements
         and conditions to be performed or satisfied by such party.

                  (b)  ATC  shall  cooperate  and use  its  reasonable  business
         efforts to cause its  independent  accountants to reasonably  cooperate
         with ATS, and at ATS' expense,  in order to enable ATS to have ATC's or
         ATS' independent  accountants prepare audited financial  statements for
         ATC described in Section 7.2(d).  ATC will use its reasonable  business
         efforts  to  ensure  that  such  financial  statements  will  have been
         prepared in accordance with GAAP applied on a basis consistent with the
         ATC  Financial  Statements  and will  present  fairly  in all  material
         respects the financial condition, results of operation and cash flow of
         ATC. Without limiting the generality of the foregoing,  ATC agrees that
         it will (i) consent to the use of such audited financial  statements in
         any  registration,  proxy or  information  statement or other  document
         filed by ATS or any of its  Affiliates  under the Securities Act or the
         Exchange Act and (ii)  execute and  deliver,  and cause its officers to
         execute and deliver, such  "representation"  letters as are customarily
         delivered in  connection  with audits and as ATS' or ATC's  independent
         accountants may reasonably request under the circumstances.

                  (c) Without  limiting  the  generality  of the  foregoing,  as
         promptly as practicable after the execution of this Agreement,  ATS and
         ATC shall,  at the written  request of the other made from time to time
         within thirty (30) days of the date of this Agreement, deliver or cause
         to be  delivered  to ATC or ATS, as the case may be,  copies of (i) all
         title report and title  insurance and (ii) Phase I  environmental  site
         assessment reports or other  environmental  reports or studies in their
         possession with respect to real property owned or leased by such party.
         Each of ATS and ATC (an "investigating  party") may at its own cost and
         expense  obtain,  and deliver to the other party (the  "owning  party")
         full and complete copies of,  preliminary  title reports and/or Phase I
         environmental site assessment reports (or other  environmental  reports
         or studies)  with respect to any real  property  owned or leased by the
         owning  party  (i)  which is not  covered  by a title or  environmental
         report  delivered  to the  investigating  party or (ii) with respect to
         which the title or environment  report so furnished,  in the reasonable
         business judgment of the investigating  party,  raises questions of (x)
         defects  in  title,  in the case of  title  reports,  or (y)  potential
         liability, in the case of Phase I environmental site assessment reports
         (or other environmental reports or studies) which, in the case of title
         defects or potential  liability has had or could reasonably be expected
         to have a Material Adverse Effect on the owning or leasing party.  Site
         assessments shall be conducted by such consultants and professionals as
         ATS and ATC  shall  mutually  agree  and  shall  be  arranged  at times
         mutually  convenient  to the  parties.  Each of ATC and  ATS  shall  be
         entitled  to  have  representatives  present  at  the  time  such  site
         assessments  are  conducted,  and to have copies of all  correspondence
         with any environmental  company conducting the site assessment pursuant
         to the provisions of this Section.

                  (d) ATC agrees that prior to the Closing Date it will not make
         or permit to be made any  change  affecting  any bank,  trust  company,
         savings and loan association,  brokerage firm or safe deposit box or in
         the names of the Persons  authorized  to draw  thereon,  to have access
         thereto  or to  authorize  transactions  therein  or in such  powers of
         attorney,  or open any  additional  accounts  or  boxes  or  grant  any
         additional  powers of attorney,  without in each case  notifying ATS in
         writing on or prior to the Closing Date.

         6.3 Public Announcements.  Until the Closing or the termination of this
Agreement,  each party shall  consult  with the other  before  issuing any press
release or otherwise making any public statements with

                                      -31-


<PAGE>

respect  to this  Agreement  or the  Merger  and shall not issue any such  press
release  or make any such  public  statement  without  the prior  consent of the
other.  Notwithstanding  the foregoing,  the parties  acknowledge and agree that
they may, without each other's prior consent,  issue such press releases or make
such public  statements as may be required by Applicable  Law, in which case the
disclosing  party shall use its reasonable  business efforts to consult with the
other  party and agree upon the  nature,  content  and form of such  disclosure,
press release or other statement.

         6.4  Notification  of Certain  Matters.  Each party  shall give  prompt
notice to the other, of the occurrence or  non-occurrence  of any Event of which
such party becomes  aware the  occurrence  or  non-occurrence  of which would be
reasonably  likely  to  cause  (a) any  representation  or  warranty  made by it
contained in this  Agreement to be untrue or inaccurate in any material  respect
or (b) any failure  made by it to comply  with or satisfy,  or be able to comply
with or satisfy, in any material respect,  any covenant,  condition or agreement
to be complied  with or  satisfied  by it under this  Agreement  in any material
respect,  such that, in any such case,  one or more of the conditions of Closing
would not be  satisfied;  provided,  however,  that the  delivery  of any notice
pursuant  to this  Section  shall not limit or  otherwise  affect the rights and
remedies  available  hereunder  to  the  party  receiving  such  notice  or  the
obligations  of the party  delivering  such  notice and shall not, in any event,
affect the representations,  warranties, covenants and agreements of the parties
or the conditions to their respective obligations under this Agreement.

         6.5 No  Solicitation.  Neither ATC nor ATS shall,  nor shall  either of
them  knowingly  permit  any of its or any of  their  Representatives  or,  with
respect  to  ATS,  permit  ARS  (including,  without  limitation,  any  officer,
director,  stockholder or any investment  banker,  broker,  finder,  attorney or
accountant  retained by it) to,  initiate,  solicit or  facilitate,  directly or
indirectly,  any  inquiries  or the making of any  proposal  with respect to any
Alternative   Transaction  applicable  to  it,  engage  in  any  discussions  or
negotiations concerning,  or provide to any other Person any information or data
relating to, it for the  purposes of, or otherwise  cooperate in any way with or
assist or  participate  in, or  facilitate  any  inquiries  or the making of any
proposal which constitutes, or may reasonably be expected to lead to, a proposal
to seek or effect any Alternative  Transaction  applicable to it, or agree to or
endorse any  Alternative  Transaction  applicable to it. If ATC or ATS or any of
its  Representatives  receives  any  inquiry  with  respect  to  an  Alternative
Transaction  applicable to it while this Agreement is in effect,  ATC or ATS, as
the case may be,  shall  inform the  inquiring  party that it is not entitled to
enter  into  discussions  or  negotiations   relating  to  such  an  Alternative
Transaction.  The provisions of this Section shall apply to all  Subsidiaries of
ATC and ATS.

         6.6 Conduct of Business by ATS Pending the Merger. Without limiting any
other  covenant  or  agreement  of ATS set  forth in this  Agreement,  except as
otherwise  permitted  or  contemplated  by  this  Agreement,  including  without
limitation pursuant to the ATS Separate Agreement and, in the case of paragraphs
(a) and (b)(ii)  and (iii),  the Tower  Distribution,  after the date hereof and
prior to the Closing Date or earlier  termination of this  Agreement  unless ATC
shall otherwise agree in writing,  ATS shall, and shall cause its  Subsidiaries,
to:

                  (a) conduct its  business in the  ordinary and usual course of
         business and consistent  with past practice,  it being  understood that
         the  acquisition of  communications  sites and related assets and other
         business  involved  in  the  communications   sites  industry  and  the
         construction  and  maintenance  of  communications  towers and  related
         assets is part of the  ordinary  course of business  of ATS;  provided,
         however,  that any such  acquisition or construction  activity shall be
         subject to the other  paragraphs  of this  Section,  including  without
         limitation paragraphs (d) and (l);

                                      -32-
<PAGE>


                  (b) not (i) amend or propose to amend their respective Organic
         Documents, (ii) split, combine or reclassify (whether by stock dividend
         or otherwise) its  outstanding  capital stock or issue or authorize the
         issuance  of any  other  securities  in  respect  of, in lieu of, or in
         substitution  for shares of its capital stock,  or (iii)  declare,  set
         aside or pay any  dividend  or  distribution  payable  in cash,  stock,
         property or otherwise;

                  (c) not  issue,  sell,  transfer,  assign,  convey,  pledge or
         dispose of, or agree to issue, sell, transfer,  assign,  convey, pledge
         or dispose of, any shares of ATS Common Stock,  Convertible Securities,
         Option Securities or other equity securities;

                  (d) not (i) incur or become  contingently  liable with respect
         to any  Indebtedness  for Money Borrowed other than (x) borrowings,  in
         addition to those  permitted or consented to pursuant to the provisions
         of clause (y) immediately  following,  not to exceed the sum of (I) the
         principal  amount of  borrowings  presently  outstanding  and (II) $5.0
         million  in  the  aggregate  outstanding  at  any  one  time,  and  (y)
         borrowings necessary to finance acquisitions and construction  projects
         permitted  or consented  pursuant to the  provisions  of paragraph  (l)
         below, (ii) redeem,  purchase,  acquire or offer to purchase or acquire
         any  shares of its  capital  stock,  Convertible  Securities  or Option
         Securities (iii) sell, lease, license,  pledge,  dispose of or encumber
         any properties or assets or sell any businesses other than (A) pursuant
         to  agreements  which  are  described  in  Section  6.6(d)  of the  ATS
         Disclosure   Schedule,   (B)  Liens  arising  in  accordance  with  the
         provisions  of  indebtedness  in  effect  on  the  date  hereof  and in
         accordance  with  their  present  terms,  and (C)  leases of towers and
         shelter  space  to  third-party  customers,  or (iv)  make  any  loans,
         advances  or capital  contributions  to, or  investments  in, any other
         Person, except to officers and employees of ATS for travel, business or
         relocation  expenses in the ordinary course of business consistent with
         past practices;

                  (e) use  reasonable  business  efforts to preserve  intact its
         business organization and goodwill,  keep available the services of its
         present  officers  and key  employees,  and  preserve  the goodwill and
         business  relationships  with  customers  and  others  having  business
         relationships  with them and not  engage  in any  action,  directly  or
         indirectly,  with the  intent  to  adversely  impact  the  transactions
         contemplated by this Agreement;

                  (f) at ATC's  reasonable  request,  confer on a regular  basis
         with one or more  representatives of ATC to report material operational
         matters and the general status of ongoing operations, including without
         limitation the status of pending and  prospective  acquisitions  and of
         the  CBS  Merger,  including  the  satisfaction  of the  conditions  to
         consummation  thereof,  to the extent  permitted or not  restricted  by
         confidentiality provisions;

                  (g) not adopt,  enter into, amend or terminate any employment,
         severance,  special  pay  arrangement  with  respect to  employment  or
         termination of employment or other similar  arrangements  or agreements
         with any directors, officers or key employees;

                  (h) maintain with financially  responsible insurance companies
         insurance  on the ATS Assets and the ATS  Business in such  amounts and
         against such risks and losses as are consistent with past practice;

                  (i) not make any Tax election that could  reasonably be likely
         to have a Material  Adverse  Effect on ATS or settle or compromise  any
         material income Tax liability;

                                      -33-
<PAGE>


                  (j) except in the ordinary  course of business,  not modify or
         amend  in  any  material  adverse  manner  or  terminate  any  Material
         Agreement to which ATS is a party or by which any of the ATS Assets may
         be bound or to which any of them may be  subject  or waive,  release or
         assign any material rights or claims thereunder;

                  (k) not make any material  change to its  accounting  methods,
         principles or practices, except as may be required by GAAP;

                  (l) not  enter  into or  agree to  enter  into any  Restricted
         Transaction (or group of related Restricted Transactions),  whether for
         its own account or for any other Person,  if (i) the  aggregate  amount
         reasonably expected to be expended by ATS or any of its Subsidiaries in
         connection with such individual  Restricted  Transaction (together with
         any group of related Restricted  Transactions) exceeds $5.0 million, or
         (ii)  the  aggregate  amount  to be  expended  in  connection  with all
         Restricted  Transactions (together with any group of related Restricted
         Transactions)  exceeds  $20.0  million;  provided,  however,  that  the
         foregoing  restriction  shall not apply to any  Restricted  Transaction
         pursuant to agreements which are described in Section 6.6(l) of the ATS
         Disclosure Schedule. (ATC agrees not to unreasonably withhold, delay or
         condition a consent to any  Restricted  Transaction as to which ATS has
         requested its consent  pursuant to the  provisions of this Section,  it
         being understood that any such consent shall not, however,  relieve ATS
         from the  obligation to comply with the  provisions  of this  Agreement
         (other than, to the extent so consented  to,  paragraph (d) hereof) and
         shall  not  be  deemed  to  be a  waiver  of  any  condition  of  ATC's
         obligations to consummate the Merger set forth in Section 7.3);

                  (m) except as set forth in Section 5.13 of the ATS  Disclosure
         Schedule,  (i) not grant to any executive officer or other key employee
         of ATS any increase in compensation, except for normal increases in the
         ordinary  course of business  consistent  with past practice,  (ii) not
         grant to any such  executive  officer  any  increase  in  severance  or
         termination  pay,  (iii)  not  adopt  or  amend  any  Plan  or  Benefit
         Arrangement (including change any actuarial or other assumption used to
         calculate  funding  obligations with respect to any Plan, or change the
         manner  in which  contributions  to any  Plan are made or the  basis on
         which  such  contributions  are  determined)  and  (iv)  except  in the
         ordinary  course,  not enter  into,  amend in any  material  respect or
         terminate   any    Governmental    Authorization,    material   Private
         Authorization  or  Contract,  except,  for purposes of this clause (iv)
         only, as would not,  individually  or in the  aggregate,  be reasonably
         likely to have a Material Adverse Effect on ATS;

                  (n) not  voluntarily  take or permit  to be taken  any  action
         which if taken  between the end of its most recent  fiscal  quarter and
         prior to the date of this  Agreement  would  have been  required  to be
         noted as an exception on Section 5.15 of the ATS  Disclosure  Schedule,
         other than as permitted or not  restricted by the preceding  provisions
         of this Section 6.6; and

                  (o) not  authorize  or enter  into any  agreement  that  would
         violate any of the foregoing.

         6.7 Conduct of Business by ATC Pending the Merger. Without limiting any
other  covenant  or  agreement  of ATC set  forth in this  Agreement,  except as
otherwise  permitted  or  contemplated  by this  Agreement,  or as set  forth or
described in the ATC Disclosure Schedule, after the date hereof and prior to the
Closing  Date  or  earlier  termination  of this  Agreement,  unless  ATS  shall
otherwise consent in writing, ATC shall, and shall cause its Subsidiaries to:

                                      -34-
<PAGE>


                  (a) conduct its  business in the  ordinary and usual course of
         business and consistent  with past practice,  it being  understood that
         the  acquisition of  communications  sites and related assets and other
         business  involved  in  the  communications   sites  industry  and  the
         construction  and  maintenance  of  communications  towers and  related
         assets is part of the  ordinary  course of business  of ATC;  provided,
         however,  that any such  acquisition or construction  activity shall be
         subject to the other  paragraphs  of this  Section,  including  without
         limitation paragraphs (d) and (l);

                  (b) not (i) amend or propose to amend their respective Organic
         Documents, (ii) split, combine or reclassify (whether by stock dividend
         or otherwise) its  outstanding  capital stock or issue or authorize the
         issuance  of any  other  securities  in  respect  of, in lieu of, or in
         substitution  for shares of its capital stock,  or (iii)  declare,  set
         aside or pay any  dividend  or  distribution  payable  in cash,  stock,
         property or otherwise;

                  (c) not  issue,  sell,  transfer,  assign,  convey,  pledge or
         dispose of, or agree to issue, sell, transfer,  assign,  convey, pledge
         or dispose of, any shares of ATC Common Stock,  Convertible Securities,
         Option Securities or other equity securities;

                  (d) not (i) incur or become  contingently  liable with respect
         to any  Indebtedness  for Money Borrowed other than (x) borrowings,  in
         addition to those  permitted or consented to pursuant to the provisions
         of clause (y) immediately following,  not to exceed $2.5 million in the
         aggregate outstanding at any one time, (y) borrowings necessary to fund
         finance acquisitions or construction projects permitted pursuant to the
         provisions  of  paragraph  (l)  below  or to fund  bonus  payments  and
         transaction fees permitted by the provisions of this Agreement, and (z)
         up to $4.5 million of  subordinated  borrowings to exercise  redemption
         rights with respect to ATC's preferred  stock,  (ii) redeem,  purchase,
         acquire  or offer to  purchase  or acquire  any  shares of its  capital
         stock,  Convertible  Securities or Option Securities (iii) sell, lease,
         license,  pledge,  dispose  of or  encumber  any  properties  or assets
         (except  for  nonstrategic  assets  that in the  aggregate  have a fair
         market value of less than $1.0  million) or sell any  businesses  other
         than (A) pursuant to agreements  which are described in Section  6.7(d)
         of the ATC Disclosure  Schedule,  (B) Liens arising in accordance  with
         the  provisions  of  indebtedness  in effect on the date  hereof and in
         accordance  with  their  present  terms,  and (C)  leases of towers and
         shelter space to third-party customers or (iv) make any loans, advances
         or capital  contributions  to, or  investments  in,  any other  Person,
         except  to  officers  and  employees  of ATC for  travel,  business  or
         relocation  expenses in the ordinary course of business consistent with
         past practices;

                  (e) use  reasonable  business  efforts to preserve  intact its
         business organization and goodwill,  keep available the services of its
         present officers and key employees  (other than individuals  identified
         to ATS prior to date hereof with specific reference to this provision),
         and preserve the goodwill and business relationships with customers and
         others having  business  relationships  with them and not engage in any
         action, directly or indirectly, with the intent to adversely impact the
         transactions contemplated by this Agreement;

                  (f) at ATS' reasonable request, confer on a regular basis with
         one or  more  representatives  of ATS to  report  material  operational
         matters and the general status of ongoing operations, including without
         limitation the status of pending and  prospective  acquisitions  to the
         extent permitted or not restricted by confidentiality provisions;

                                      -35-
<PAGE>


                  (g) not adopt,  enter into, amend or terminate any employment,
         severance,  special  pay  arrangement  with  respect to  employment  or
         termination of employment or other similar  arrangements  or agreements
         with any directors, officers or key employees;

                  (h) maintain with financially  responsible insurance companies
         insurance  on the ATC Assets and the ATC  Business in such  amounts and
         against such risks and losses as are consistent with past practice;

                  (i) not make any Tax election that could  reasonably be likely
         to have a Material  Adverse  Effect on ATC or settle or compromise  any
         material income Tax liability;

                  (j) except in the ordinary  course of business,  not modify or
         amend in a manner  materially  adverse to ATC or terminate any Material
         Agreement to which ATC is a party or by which any of the ATC Assets may
         be bound or to which any of them may be  subject  or waive,  release or
         assign any material rights or claims thereunder;

                  (k) not make any material  change to its  accounting  methods,
         principles or practices, except as may be required by GAAP;

                  (l) not  enter  into or  agree to  enter  into any  Restricted
         Transactions (or group of related Restricted Transactions), whether for
         its own account or for any other Person,  if (i) the  aggregate  amount
         reasonably expected to be expended by ATC or any of its Subsidiaries in
         connection with such individual  Restricted  Transaction (together with
         any group of related Restricted  Transactions) exceeds $5.0 million, or
         (ii)  the  aggregate  amount  to be  expended  in  connection  with all
         Restricted  Transactions (together with any group of related Restricted
         Transactions)  exceeds  $20.0  million;  provided,  however,  that  the
         foregoing restriction shall not apply to any Restricted Transaction
         pursuant to agreements which are described in Section 6.7(l) of the ATC
         Disclosure Schedule. (ATS agrees not to unreasonably withhold, delay or
         condition a consent to any  Restricted  Transaction as to which ATC has
         requested its consent  pursuant to the  provisions of this Section,  it
         being understood that any such consent shall not, however,  relieve ATC
         from the  obligation to comply with the  provisions  of this  Agreement
         (other than, to the extent so consented  to,  paragraph (d) hereof) and
         shall not be deemed to be a waiver of any condition of ATS' obligations
         to consummate the Merger set forth in Section 7.2);

                  (m) except as set forth in Section 4.14 of the ATC  Disclosure
         Schedule,  (i) not grant to any executive officer or other key employee
         of ATC any increase in compensation, except for normal increases in the
         ordinary  course  of  business  consistent  with  past  practice  or as
         required under Benefit Arrangements in effect as of September 30, 1997,
         (ii) not grant to any such executive  officer any increase in severance
         or  termination   pay,   except  as  was  required  under  any  Benefit
         Arrangements  in effect as of September  30,  1997,  (iii) not adopt or
         amend any Plan or Benefit  Arrangement  (including change any actuarial
         or other assumption used to calculate funding  obligations with respect
         to any Plan,  or change the manner in which  contributions  to any Plan
         are made or the basis on which such  contributions  are determined) and
         (iv)  except  in the  ordinary  course,  not enter  into,  amend in any
         material respect or terminate any Governmental Authorization,  material
         Private Authorization or Contract,  except, for purposes of this clause
         (iv)  only,  as  would  not,  individually  or  in  the  aggregate,  be
         reasonably likely to have a Material Adverse Effect on ATC;

                                      -36-
<PAGE>


                  (n) not  voluntarily  take or permit  to be taken  any  action
         which if taken  between the end of its most recent  fiscal  quarter and
         prior to the date of this  Agreement  would  have been  required  to be
         noted as an exception on Section 4.16 of the ATC  Disclosure  Schedule,
         other than as permitted or not restricted pursuant to the provisions of
         this Section 6.7; and

                  (o) not  authorize  or enter  into any  agreement  that  would
         violate any of the foregoing.

         6.8 Directors', Officers' and Employees' Indemnification and Insurance.

                  (a) The Organic  Documents of ATS shall contain  provisions no
         less  favorable with respect to  indemnification  than are set forth in
         the Organic  Documents of ATS, as in effect on the date  hereof,  which
         provisions shall not be amended,  repealed or otherwise  modified for a
         period of six (6) years  from the  Effective  Time in any  manner  that
         would affect adversely the rights  thereunder of individuals who at any
         time prior to the Effective Time were directors,  officers or employees
         of ATC or any of its Subsidiaries,  unless such  modification  shall be
         required by Applicable Law.

                  (b) From and after the Effective  Time,  ATS shall  indemnify,
         defend and hold harmless the present and former officers, directors and
         employees  of  ATC  or  any  of  its  Subsidiaries  (collectively,  the
         "Indemnified Parties") against all losses,  expenses,  claims, damages,
         liabilities  or amounts that are paid in settlement of, or otherwise in
         connection with any claim,  action,  suit,  proceeding or investigation
         (as used in this Section, a "claim"),  based in whole or in part on the
         fact  that the  Indemnified  Party  (or the  Person  controlled  by the
         Indemnified Party) is or was a director,  officer or employee of ATC or
         any  of its  Subsidiaries  and  arising  out of  actions  or  omissions
         occurring  at or  prior  to  the  Effective  Time  (including,  without
         limitation,  in  connection  with this  Agreement,  the  Merger and the
         transactions  contemplated  hereby),  whether asserted or claimed prior
         to, at or after the Effective  Time, in each case to the fullest extent
         permitted  under the DCL (and shall pay any expenses,  as incurred,  in
         advance of the final  disposition  of any such action or  proceeding to
         each Indemnified  Party to the fullest extent permitted under the DCL).
         Without limiting the foregoing,  in the event any such claim is brought
         against any of the Indemnified  Parties,  (i) such Indemnified  Parties
         may retain counsel  (including local counsel)  satisfactory to them and
         which  shall be  reasonably  satisfactory  to ATS and ATS shall pay all
         reasonable  fees and  expenses  of such  counsel  for such  Indemnified
         Parties;  and (ii) ATS  shall  use its best  efforts  to  assist in the
         defense of any such  claim;  provided,  however,  that ATS shall not be
         liable for any settlement  effected without its written consent,  which
         consent shall not be unreasonably withheld, delayed or conditioned.

                  (c) ATS will use its best  efforts  to cause to be  maintained
         for a period of not less than six (6) years from the  Effective  Time a
         directors'  and  officers'  insurance and  indemnification  policy that
         provides  coverage for events  occurring  on or prior to the  Effective
         Time ("D&O  Insurance")  for all Persons who are directors and officers
         of ATC or any of its  Subsidiaries  on the date of this  Agreement,  so
         long as the annual premium therefor would not be in excess of $500,000.
         If any then existing D&O Insurance  expires,  is terminated or canceled
         during such six-year period,  ATS will use its best efforts to cause to
         be obtained as much D&O  Insurance as can be obtained for the remainder
         of such period for an annualized premium not in excess of $500,000,  on
         terms and conditions no less  advantageous  to the covered Persons than
         the then existing D&O Insurance.

                  (d) In the event ATS or any of their respective  successors or
         assigns (i) consolidates with or merges into any other person and shall
         not be the  continuing  or  surviving  corporation  or  entity  of such
         consolidation or merger or (ii) transfers all or  substantially  all of
         its  properties  and assets to any 

                                      -37-
<PAGE>


         person,  then and in each such case, proper provisions shall be made so
         that the successors and assigns of ATS shall assume the obligations set
         forth in this Section.

                  (e) This  Section is  intended  to be for the  benefit of, and
         shall be  enforceable  by, the  Indemnified  Parties,  their  heirs and
         personal representatives and shall be binding on ATS and its successors
         and  assigns.  ATS shall  furnish ATC with a copy of the D&O  insurance
         complying  with the  provisions  of this Section 6.8 at or prior to the
         Closing.

         6.9 ATC Employees and Benefit Plans.

                  (a)  Notwithstanding  any  provision in this  Agreement to the
         contrary,  on or prior to the Closing Date, ATC may (i) take any action
         permitted under Paragraph  VIII(c) of ATC's 1995 Stock Option Plan with
         respect to any or all Option  Securities  issued and outstanding  under
         such plan, (ii) accelerate the vesting and exercisability of any or all
         of  such  Option  Securities,  (iii)  amend  any  or  all  such  Option
         Securities to provide that such Option  Security  shall  continue to be
         exercisable for its entire stated term without regard to the employment
         status or death of the  holder of such  Option  Security,  and (iv) pay
         bonuses to the employees of ATC and its Subsidiaries in such amounts as
         ATC shall determine in its sole discretion; provided, however, that (A)
         the  aggregate  amount of the bonuses  paid  pursuant to clause (iv) of
         this sentence, when added to any fees or expense reimbursements paid or
         payable to any  financial  advisers  in  connection  with the Merger or
         related financial  advice,  shall not exceed $5.0 million (which amount
         shall not include  nor be reduced by any  performance  bonuses  paid to
         employees of ATC and its  Subsidiaries  with  respect to calendar  year
         1997 on a basis consistent with past practices), and (B) ATC shall have
         any  action or  payment  described  in this  sentence  approved  by the
         stockholders  of ATC in  accordance  with  the  provisions  of  Section
         280G(b)(5)  of the  Code to the  extent  necessary  to  ensure  that no
         actions taken with respect to the employees of ATC and its Subsidiaries
         or payments  made to such  employees  would result in imposition of the
         sanctions  imposed under  Sections 280G and 4999 of the Code. Any bonus
         paid pursuant to clause (iv) of the  preceding  sentence may be paid in
         cash, by reducing the purchase price of shares of ATC Common Stock that
         may be acquired under an Option  Security issued under ATC's 1995 Stock
         Option Plan, or any combination of the foregoing.  Any actions taken or
         payments made by ATC pursuant to the  provisions of this Section 6.9(a)
         may vary among the individual employees of ATC and its Subsidiaries and
         may vary among the Option  Securities held by any individual  employee,
         all as determined by ATC in its sole discretion.

                  (b) ATS shall take such action as may be  necessary so that at
         the  Effective   Time  and  for  twelve  (12)  months   thereafter  the
         individuals  employed by ATC and its Subsidiaries  immediately prior to
         the  Effective  Time (the  "Continued  Employees")  shall  receive base
         compensation  (i.e.,  salary and wages) at a rate that is not less than
         that  received by such  Continued  Employees  immediately  prior to the
         Closing Date;  provided,  however,  that the foregoing provisions shall
         not impair ATS' ability to terminate  any such  Continued  Employee for
         cause.  If, within the  twelve-month  period beginning at the Effective
         Time, the employment of any Continued  Employee is terminated by ATS or
         any of its Subsidiaries other than for cause, or any Continued Employee
         is  required  to  accept a  material  reduction  in his or her title or
         responsibilities  or to  transfer to a job  location  that is more than
         thirty-five (35) miles from his or her job location  immediately  prior
         to the Effective  Time, but refuses such  reduction or transfer  within
         fifteen (15) days of notice of such  reduction  or  transfer,  then ATS
         shall continue to pay such  Continued  Employee his or her base rate of
         pay for the balance of such twelve-month period (without mitigation for
         any subsequent  employment by such continued 

                                      -38-
<PAGE>

         employee).   The  provisions  of  this  Section  6.9(b)  shall  not  be
         applicable with respect to Fred R. Lummis.

                  (c) ATS shall take such action as may be  necessary so that on
         and after the  Effective  Time and for twelve (12)  months  thereafter,
         officers and  employees of ATC and its  Subsidiaries  shall be provided
         employee  benefits,  plans and  programs  (excluding  equity  incentive
         arrangements)  which are no less  favorable in the aggregate than those
         generally  available  pursuant  to those  employee  benefit  plans  and
         programs in effect for such officers and employees immediately prior to
         the Effective  Time; it being  understood  that ATS shall determine the
         types and levels of specific  benefits to be so provided.  For purposes
         of  eligibility  to  participate,  vesting and  benefit  determinations
         (other than benefit  accruals  under any defined  benefit  plan) in all
         benefits   provided  to  officers   and   employees   of  ATC  and  its
         Subsidiaries,  such officers and employees of ATC and its  Subsidiaries
         will be credited with their service with ATC and its  Subsidiaries  and
         their respective  predecessors.  Upon termination of any health plan of
         ATC or any  of its  Subsidiaries,  individuals  who  were  officers  or
         employees of ATC or its  Subsidiaries  at the  Effective  Time shall if
         employed by ATS or its  Subsidiaries  become eligible to participate in
         such health plans as may be  established  or  maintained  by ATS or its
         Subsidiaries  to the extent that such  individuals  and their  eligible
         dependents  were eligible to participate in the applicable  health plan
         of ATC or its  Subsidiaries  immediately  prior to the Effective  Time.
         Amounts paid during the calendar  year in which such change of coverage
         occurs by officers and employees of ATC and its Subsidiaries  under any
         health  plans of ATC shall after such  change be taken into  account in
         applying  deductible  and  out-of-pocket  limits  applicable  under the
         health plans of ATS or its  Subsidiaries  provided during such calendar
         year to the same  extent as if such  amounts  had been paid  under such
         health  plans  of ATS or its  Subsidiaries  and ATS  shall  cause to be
         waived under its health  plans any  pre-existing  conditions  as of the
         date  of  termination  of  the  ATC  health  plan  and  eligibility  to
         participate in such health plan to the extent such conditions  would be
         waived under the  applicable  plans of ATC and its  Subsidiaries  as in
         effect on the date hereof. Nothing in this Agreement shall be construed
         as granting to any  employee of ATC or its  Subsidiaries  any rights of
         continuing employment.

         6.10 ATC Stock Options.  Prior to the Effective Time, ATS and ATC shall
take such action as may be necessary  to cause each  unexpired  and  unexercised
option to purchase ATC Common Stock that is outstanding immediately prior to the
Merger  (each,  an "ATC  Option"  and  collectively,  the "ATC  Options")  to be
automatically  converted at the  Effective  Time into an option  (each,  an "ATS
Option" and  collectively,  the "ATS Options") to purchase a number of shares of
ATS Class A Common  Stock  equal to the  product  of the number of shares of ATC
Common  Stock  which the holder is  entitled  to  purchase  under the ATC Option
multiplied  by the  Exchange  Ratio,  at a price per share equal to the quotient
obtained by dividing (a) the per share option exercise price determined pursuant
to the ATC Option by (b) the Exchange Ratio. Each ATS Option will otherwise have
the same terms and conditions as the ATC Option  exchanged  therefor,  including
acceleration and period of exercise. At the Effective Time, ATS will execute and
deliver to each holder of an ATS Option a document  evidencing ATS'  assumptions
of ATC's obligations under the ATC Option and all references in the stock option
agreements to ATC shall be deemed to refer to ATS. As of the Effective Time, ATS
shall  assume all of ATC's  obligations  with  respect to the ATC  Options as so
amended and shall, from and after the Effective Time, have reserved for issuance
upon  exercise of the ATS Options all shares of ATS Class A Common Stock covered
thereby and shall file a  Registration  Statement  on Form S-8 to  register  the
shares  of ATS  Class A Common  Stock  subject  to the ATS  Options  granted  in
replacement of ATC Options.  ATS shall take all actions reasonably  necessary to
maintain the  effectiveness  of such  Registration  Statement  (and maintain the
current status of the prospectus or prospectuses  contained therein) for so long
as such ATS Options  remain  outstanding.  No  fractional  shares of ATS Class A
Common Stock will be issued upon the

                                      -39-
<PAGE>

exercise of any ATS Option, and instead the exercising holder of such ATS Option
shall receive cash for any fractional  share  amounts,  based on the fair market
value of the ATS Class A Common Stock at the time of exercise.

         6.11 ATS Voting Agreement. ATS shall use its best efforts to cause each
of the  Persons  named  therein  to  execute  and  deliver  to ATC an  agreement
substantially  in the form of Exhibit C attached  hereto and made a part  hereof
(collectively, the "ATS Voting Agreement").

         6.12 Stockholder  Approval.  ATC will, as soon as practicable following
the date thereof,  establish a record date (which will be as soon as practicable
following the date hereof) for, and, after the Registration Statement has become
effective,  duly  call,  give  notice  of,  convene  and hold a  meeting  of its
stockholders (the "ATC  Stockholders  Meeting") for the purpose of obtaining the
approval  and adoption of this  Agreement  and the approval of the Merger by the
ATC stockholders (the "ATC Stockholder  Approval").  ATC will, through its Board
of  Directors,  recommend  to its  stockholders  approval  and  adoption of this
Agreement and approval of the Merger.

         6.13 Registration Statement and Proxy/Information Statement.

                  (a) ATS shall prepare and file with the  Commission as soon as
         is  reasonably   practicable  after  the  date  hereof  a  Registration
         Statement under the Securities Act (the "ATS  Registration  Statement")
         on  Form  S-4  in  connection  with  the  Merger  for  the  purpose  of
         registering  all of the shares of ATS Class A Common Stock to be issued
         in the Merger. ATS shall also take any action required under Applicable
         Law in connection with causing the ATS Registration  Statement declared
         effective  by the  Commission  as  promptly as  practicable,  including
         without  limitation  making all filings under applicable state blue sky
         or  securities  laws in  connection  with the  issuance  of ATS Class A
         Common Stock in the Merger.  ATS shall  promptly  furnish to each other
         all  information,  and take such other  actions,  as may  reasonably be
         requested in connection with any action by either of them in connection
         with the provisions of this Section.

                  (b) ATC shall, as soon as is reasonably  practicable after the
         effectiveness of the ATS Registration Statement, mail notice to the ATC
         common stockholders of the ATC Stockholders  Meeting. Such notice shall
         comply  with  the  provisions  of  Applicable  Law.  ATS and ATC  shall
         promptly  furnish  to the other all  information,  and take such  other
         actions,  as may reasonably be requested in connection  with any action
         taken to comply with the provisions of this Section,  including, in the
         case  of  ATS,  the  final   prospectus  (the  "ATS   Prospectus"  and,
         collectively  with the  notice  furnished  to the ATC  stockholders  in
         connection  with the ATC  Stockholders  Meeting,  the "ATC  Stockholder
         Information") contained in the ATS Registration Statement.

                  (c) Each of ATC and ATS shall correct promptly any information
         provided  by  it  to be  used  specifically  in  the  ATS  Registration
         Statement and the ATC  Stockholder  Information  that shall have become
         false or  misleading  in any  material  respect  and ATS shall take all
         steps  necessary  to file with the  Commission  and have cleared by the
         Commission  any  amendment  or  supplement  to  the  ATS   Registration
         Statement so as to correct such  information  and ATS shall cause it to
         be  disseminated  to the ATC  stockholders,  to the extent  required by
         Applicable Law. Without  limiting the generality of the foregoing,  ATS
         shall  notify  ATC  promptly  of the  receipt  of the  comments  of the
         Commission  and of any  request by the  Commission  for  amendments  or
         supplements to the ATS Registration Statement or the ATS Prospectus, or
         for  additional  information,  and shall  supply ATC with copies of all
         correspondence between it or its representatives,  on the one hand, and
         the Commission or members

                                      -40-
<PAGE>

         of its staff, on the other hand,  with respect to the ATS  Registration
         Statement or the ATS Prospectus. Whenever any event occurs which should
         be described in an  amendment or a supplement  to the ATS  Registration
         Statement  or the ATS  Prospectus,  ATS shall,  upon  learning  of such
         event,  promptly  prepare,  file and clear with the  Commission and ATS
         shall  mail to the  ATC  stockholders  such  amendment  or  supplement;
         provided,  however,  that, prior to such mailing, (i) ATS shall consult
         with ATC with  respect  to such  amendment  or  supplement,  (ii) shall
         afford ATC reasonable  opportunity to comment  thereon,  and (iii) each
         such amendment or supplement shall be reasonably satisfactory to ATC.

                  (d) ATC shall use its reasonable  business efforts to cause to
         be delivered to ATS and its directors a letter of independent auditors,
         dated  (i) the  date of the ATS  Prospectus  Statement,  and  (ii)  the
         Closing Date,  and addressed to ATS and its directors,  in form,  scope
         and substance  customary for letters  delivered by  independent  public
         accountants in connection with registrations  statements similar to the
         ATS Registration Statement.

         6.14 Listing of ATS Class A Common Stock.  ATS shall use its reasonable
business efforts to effect,  at or before the Effective Time,  authorization for
listing on Nasdaq (or such stock exchange as ATS shall have reasonably selected)
upon official  notice of issuance,  of the additional  shares of the ATS Class A
Common Stock to be issued pursuant to the Merger;  provided,  however, that such
efforts shall not require the elimination of the different  voting rights of the
classes of ATS Common Stock.

         6.15 Solicitation of Employees.  If this Agreement is terminated,  each
of ATS and ATC agrees  that  neither it nor any of its  Affiliates  will,  for a
period of eighteen  (18) months  from the date of such  termination,  solicit or
actively  seek to hire any person who during  such  period is employed by ATC or
any of its  Affiliates  or ATS or any of its  Affiliates,  as the  case  may be,
whether  or not  such  individual  would  commit  breach  of  such  individual's
employment agreement or contact in leaving such employment;  provided,  however,
that  the  foregoing  shall  not  prevent  ATS or ATC (or any of its  respective
Affiliates)  from  soliciting or actively  seeking to hire any such key employee
who (i) initiates employment discussions with it, (ii) is not employed by ATS or
ATC,  as the case may be,  on the  date  ATC or ATS,  as the case may be,  first
solicits such key employee, or (iii) soliciting through general advertisement.

         6.16 Additional Tax Matters.

                  (a) Except for  transactions  in the ordinary and usual course
         of business,  following the date on which, for purposes of Section 1504
         of the Code,  ATS  ceases to be a member of the  "affiliated  group" of
         corporations of which ARS is the "common parent",  ATS shall not engage
         in any  transaction  and shall not  permit  an of its  Subsidiaries  to
         engage in any  transaction  that would be  treated as an  "intercompany
         transaction" as defined in Treas. Reg. ss. 1.1502-13.

                  (b)  Each  party  hereto  shall  use all  reasonable  business
         efforts to cause the Merger to qualify,  and shall not take,  and shall
         use all  reasonable  business  efforts to prevent any Affiliate of such
         party from  taking,  any action  which  could  prevent  the Merger from
         qualifying,  as a reorganization under the provisions of Section 368(a)
         of the Code.

         6.17 ATS Registration Rights Agreement. Subject to the satisfaction (or
waiver) of the  conditions to closing set forth in (a) Sections 7.1 and 7.2 (the
"ATS Conditions"),  at or prior to the Closing,  ATS shall execute and deliver a
registration  rights  agreement  substantially  in the form  attached  hereto as
Exhibit D and made a part hereof (the "ATS Registration  Rights  Agreement") and
permit  the  ATS  Registration  Statement

                                      -41-
<PAGE>


to be executed by such of the ATC  stockholders as elect to be so included,  and
(b) Sections 7.1 and 7.3 (the "ATC  Conditions"),  ATC shall use its  reasonable
business  efforts to cause ATC's two largest  stockholders and Fred R. Lummis to
the extent any of them may be an "affiliate", as that term is used in paragraphs
(c) and (d) of Rule 145 under the Securities Act, of ATS, to execute and deliver
the ATS Registration Rights Agreement.

         6.18 Charter Amendment.  Subject to the satisfaction (or waiver) of the
ATS  Conditions,  at or prior to the  Closing,  ATS shall cause the ATS Restated
Certificate to be approved by the Board of Directors and stockholders of ATS and
to be filed with the Secretary of State of the State of Delaware.

         6.19  Conversion of Class B Common Stock.  Subject to the  satisfaction
(or waiver) of the ATS Conditions,  at or prior to the Closing,  ATS shall cause
the ATS  Class B Common  Stock  issued to  Steven  B.  Dodge in the ATS  Private
Placement  to be  converted  into a like  number of shares of ATS Class A Common
Stock to the extent that, after giving effect to the consummation of the Merger,
Steven B. Dodge, Chairman of the Board and Chief Executive Officer of ATS, would
own more than  49.99% of the  voting  power of the ATS Common  Stock  within the
meaning of the ATS  Restated  Certificate.  ATS shall ensure that no ATS Class B
Common  Stock is issued in the ATS Private  Placement  to any Person  other than
Steven B. Dodge and Thomas H. Stoner,  in each case, to the extent  permitted by
the provisions of this Section and Section 6.25.

         6.20 ATS  Separation  Agreement.  Unless  previously  entered  into and
subject to the  satisfaction  (or waiver) of the ATS Conditions,  at or prior to
the Closing, ATS shall, and shall ARS to, execute and deliver the ATS Separation
Agreement.

         6.21 CBS Merger or Tower Distribution  Related Actions.  Subject to the
satisfaction (or waiver) of the ATS Conditions,  at or prior to the Closing, ATS
shall, and shall cause ARS to, use its reasonable  business efforts to cause (a)
the CBS Merger to occur,  or, if the Tower  Distribution is required in order to
satisfy the ATC  Conditions,  and (b) the Tower  Distribution  to occur, in each
case,  in a manner  that does not result in a default in, or with the passage of
time or giving of notice  would not result in a default in or  violation  of any
Material Agreement to which ATS or ARS is a party or by which it is bound or the
Organic  Documents of ATS or ARS,  including  without  limitation the ATS Credit
Agreement, the ARS Credit Agreement and the ARS Cumulative Preferred Stock.

         6.22 Efforts Regarding Pending  Transactions.  ATS shall use reasonable
business  efforts to cause to be satisfied on or before the Termination Date all
conditions to closing  applicable to the Gearon  Transaction and the ATS Private
Placement and, upon satisfaction thereof, to consummate such transactions.

         6.23 Certain Closing Certificates.  ATC shall cause its chief financial
officer to deliver to ATS and its counsel at the Closing a  certificate  showing
his  calculation,  in reasonable  detail,  of the number of shares of ATC Common
Stock  determined on a Fully-Diluted  Basis  immediately  prior to the Effective
Time.  ATS shall  cause its chief  financial  officer  to deliver to ATC and its
counsel at the Closing a  certificate  showing his  calculation,  in  reasonable
detail,   of  the  number  of  shares  of  ATS  Common  Stock  determined  on  a
Fully-Diluted Basis immediately prior to the Effective Time.

         6.24 ATC Affiliates  Agreements.  ATC shall use its reasonable business
efforts to cause each executive officer, director and other Person who may be an
"affiliate,"  as that term is used in  paragraphs  (c) and (d) of Rule 145 under
the  Securities  Act, of ATC, to have executed and delivered to ATS an agreement
substantially  in the form of Exhibit E attached  hereto and made a part  hereof
(collectively, the "ATC Affiliate Agreements").

                                      -42-
<PAGE>


         6.25 Issue of ATS Class B Common Stock.  Subject to the satisfaction of
the ATS  Conditions,  ATS shall not issue any shares of Class B Common  Stock or
any  Convertible   Securities   convertible  or  exchangeable  into,  or  Option
Securities to purchase,  any shares of ATS Class B Common  Stock,  except (a) to
Steven B.  Dodge  and,  in the event  Class B Common  Stock  shall not have been
distributed  pursuant to the Tower  Distribution,  Thomas H. Stoner  (but,  with
respect to Mr.  Stoner,  in a number not more than he holds on the date  hereof)
pursuant to the provisions of the ATS Private  Placement,  (b) Option Securities
issued to the holders of options to purchase  Class B Common  Stock of ARS,  and
(c) upon consummation of the CBS Merger or the Tower  Distribution to holders of
Class B Common Stock of ARS. ATS will furnish to ATC, if it has not already done
so,  within five (5) business days of this  Agreement,  a list of the holders of
Class B Common  Stock of ARS or of options to purchase  Class B Common  Stock of
ARS.

         6.26 Election of ATS Directors.  Subject to the satisfaction of the ATS
Conditions,  ATS shall cause Fred R.  Lummis and  Randall  Mays to be elected as
members of the Board of Directors of ATS.

         6.27  Employee  List.  Within ten (10) days after the date hereof,  ATS
shall furnish ATS with a list of all  employees of ARS, ATS or their  respective
Subsidiaries that are expected to be employed by the Surviving Company after the
Merger, the office or title of each and the compensation of each.

         6.28 Certificates of Non-Foreign Status. Prior to the Closing Date, ATC
shall in respect of the  conversion  of ATC Common Stock  pursuant to the Merger
use its  reasonable  to obtain on behalf of itself and ATS, from each person who
is a stockholder of ATC  immediately  prior to the Effective Time, a certificate
of non-foreign status of such stockholder that meets the requirements of Section
1445 of the Code and Section 1.1445-2(b) of the Treasury Regulations thereunder,
it being understood that the failure to obtain any such certificate shall not be
deemed to be a breach of this  Section.  ATC shall furnish to ATS on the Closing
Date a copy of such certificates of non-foreign status.


                                    ARTICLE 7

                               CLOSING CONDITIONS

         7.1 Conditions to Obligations of Each Party. The respective obligations
of each party to effect the Merger  shall be subject to the  satisfaction  at or
prior to the Closing Date of the following  conditions,  any or all of which may
be waived,  in whole or in part, to the extent  permitted by  Applicable  Law by
each party benefitting therefrom:

                  (a) As of the Closing  Date, no temporary  restraining  order,
         preliminary or permanent  injunction or other order issued by any court
         of  competent  jurisdiction  or other legal  restraint  or  prohibition
         preventing the consummation of the Merger shall be in effect;

                  (b) The waiting period  applicable to the  consummation of the
         Merger and the  receipt by each ATC  common  stockholder  of the Merger
         Consideration  due  pursuant  thereto,  as the case may be,  under  the
         Hart-Scott-Rodino Act, to the extent applicable,  shall have expired or
         been terminated;


                                      -43-
<PAGE>

                  (c) The ATS Registration Statement shall have become effective
         in  accordance  with  the  provisions  of  the  Securities  Act  and in
         accordance  with the  provisions  of  Section  6.13,  and no stop order
         suspending  such  effectiveness  shall  have been  issued and remain in
         effect and no proceeding for that purpose shall have been instituted by
         the Commission or any state  regulatory  authorities  and all shares of
         ATS Common Stock to be issued to the ATC  stockholders  pursuant to the
         Merger shall be covered by the ATS Registration Statement;

                  (d) The shares of ATS Class A Common Stock to be issued in the
         Merger  shall have been  approved  for listing on Nasdaq (or such other
         national  stock  exchange  on which  such  stock is then  approved  for
         listing), upon official notice of issuance; and

                  (e) The ATC Stockholder Approval shall have been obtained.

         7.2  Conditions to  Obligations of ATS. The obligation of ATS to effect
the Merger shall be subject to the satisfaction of the following conditions, any
or all of  which  may be  waived,  in whole  or in  part,  by ATS to the  extent
permitted by Applicable Law:

                  (a) ATC shall have  furnished  ATS and, at ATS'  request,  any
         bank or other  financial  institution  providing  credit to ATS, with a
         favorable  opinion,  dated the Closing Date, of Vinson & Elkins L.L.P.,
         counsel for ATC, substantially in the form attached hereto as Exhibit F
         and made a part hereof;

                  (b) (i) The representations and warranties of ATC set forth in
         this  Agreement  (other than in Section 4.21) shall be true and correct
         as of the date hereof and as of the Closing  Date as though made on and
         as of the Closing  Date  except (x) to the extent such  representations
         and  warranties  expressly  speak as of an earlier  date (in which case
         such  representations  and  warranties  shall be true and correct as of
         such  earlier  date) and (y) to the  extent  that the  failure  of such
         representations and warranties to be true and correct,  individually or
         in the  aggregate,  would not have a  Material  Adverse  Effect on ATC;
         provided,   however,   that  for  the   purpose  of  this  clause  (y),
         representations  and  warranties  that are qualified as to  materiality
         (including  by  reference to "Material  Adverse  Effect")  shall not be
         deemed to be so qualified;  (ii) the  representations and warranties of
         ATC set  forth  in  Section  4.21 of this  Agreement  shall be true and
         correct;  provided,  however,  such untruth  shall be  disregarded  for
         purposes of this Section  7.2(b) if, by adjusting the Exchange Ratio at
         Closing,  the untruth is rendered  harmless and such adjustment  either
         does not require the approval of the ATC stockholders, or such approval
         has been  obtained,  in accordance  with the DCL; (iii) each and all of
         the agreements and covenants to be performed or satisfied by ATC or any
         of the ATC stockholders hereunder at or prior to the Closing Date shall
         have been duly  performed or satisfied  in all material  respects;  and
         (iv) an  executive  officer  of ATC shall have  furnished  ATS with his
         certificate,   confirming,   to  his  knowledge,   the  truth  of  such
         representations  and warranties  and the  performance of such covenants
         and agreements;

                  (c)  There  has not  occurred  any  Event  (including  without
         limitation the failure to secure all authorizations, consents, waivers,
         orders or approvals required to be obtained by ATC from all Authorities
         and other Person, and all filings, submissions,  registrations, notices
         or  declarations  required  to be made by any of the  parties  with any
         Authority,  or  the  imposition  of any  condition  or  requirement  in
         connection  therewith) that has had, or is reasonably likely to have, a
         Material  Adverse  Effect on ATC,  other  than an Event  affecting  the
         economy or the tower communications business

                                      -44-
<PAGE>


         generally  or an  Event  that  would  not  have  occurred  but  for the
         execution of this Agreement and the announcement of the Merger; and

                  (d) ATS shall  have  received  from its  counsel,  Sullivan  &
         Worcester  LLP, a favorable  opinion  (dated as of the Closing Date) to
         the effect  that the Merger  constitutes  a  reorganization  within the
         meaning of Section 368 of the Code and that, as a consequence, ATS will
         not  recognize  any gain or loss for federal  income tax  purposes as a
         result of  consummation  of the Merger,  and, in  connection  with such
         opinion,  ATC and such of its  stockholders  as such counsel shall have
         reasonably  requested shall have executed and delivered to ATS and such
         counsel a  certificate  substantially  in the form  attached  hereto as
         Exhibit G and made a part hereof.

         7.3  Conditions to  Obligations of ATC. The obligation of ATC to effect
the Merger shall be subject to the satisfaction of the following conditions, any
or all of  which  may be  waived,  in whole  or in  part,  by ATC to the  extent
permitted by Applicable Law:

                  (a) ATS shall have  furnished  ATC, with  favorable  opinions,
         dated the Closing Date, of Sullivan & Worcester  LLP,  counsel for ATS,
         substantially  in the form attached hereto as Exhibit H and made a part
         hereof,  and with respect to such other matters  arising after the date
         of this Agreement and incident to the Merger, as ATC or its counsel may
         reasonably request;

                  (b) (i) The representations and warranties of ATS set forth in
         this  Agreement  (other than in Section 5.20) shall be true and correct
         as of the date hereof and as of the Closing  Date as though made on and
         as of the Closing  Date  except (x) to the extent such  representations
         and  warranties  expressly  speak as of an earlier  date (in which case
         such  representations  and  warranties  shall be true and correct as of
         such  earlier  date) and (y) to the  extent  that the  failure  of such
         representations and warranties to be true and correct,  individually or
         in the  aggregate,  would not have a  Material  Adverse  Effect on ATS;
         provided,   however,   that  for  the   purpose  of  this  clause  (y),
         representations  and  warranties  that are qualified as to  materiality
         (including  by  reference to "Material  Adverse  Effect")  shall not be
         deemed to be so qualified;  (ii) the  representations and warranties of
         ATS set  forth  in  Section  5.20 of this  Agreement  shall be true and
         correct;  provided,  however,  such untruth  shall be  disregarded  for
         purposes of this Section  7.3(b) if, by adjusting the Exchange Ratio at
         Closing,  the untruth is rendered  harmless and such adjustment  either
         does not require the approval of the ATS or ARS  stockholders,  or such
         approval has been obtained,  in accordance with the DCL; (iii) each and
         all of the  agreements  and  conditions to be performed or satisfied by
         ATS or any of the ATS common stockholders  hereunder at or prior to the
         Closing Date (including  without  limitation the execution and delivery
         of all  collateral  documents to be executed and delivered by it or any
         of them) shall have been duly  performed  or  satisfied in all material
         respects; and (iv) an executive officer of ATS shall have furnished ATC
         with his certificate  confirming,  to his knowledge,  the truth of such
         representations  and warranties  and the  performance of such covenants
         and agreements;

                  (c)  There  has not  occurred  any  Event  (including  without
         limitation the failure to secure all authorizations, consents, waivers,
         orders or approvals required to be obtained by ATS from all Authorities
         and other Person, and all filings, submissions,  registrations, notices
         or  declarations  required  to be made by any of the  parties  with any
         Authority,  or  the  imposition  of any  condition  or  requirement  in
         connection  therewith) that has had, or is reasonably likely to have, a
         Material  Adverse  Effect on ATS,  other  than an Event  affecting  the
         economy or the tower communications business generally or an Event that
         would not have occurred but for the execution of this Agreement and the
         announcement of the Merger;

                                      -45-
<PAGE>


                  (d) ATC shall have received  evidence of the  consummation  of
         the Gearon Transaction and the ATS Private Placement,  all on the terms
         and conditions set forth, in the case of the Gearon Transaction, in the
         Gearon Merger Agreement, and, in the case of the ATS Private Placement,
         on the terms and conditions described in the ATS Information Statement,
         or, in either case, on such other terms and  conditions  not materially
         adverse to ATS,  including  without  limitation,  but, in any event, in
         both cases, the issuance of shares of ATS Class A Common Stock shall be
         at a price per share of not less than  $9.00 and,  with  respect to the
         ATS Private Placement for a total purchase price of not less than $80.0
         million;

                  (e)  Fred R.  Lummis,  one of the  stockholders  of  ATC,  and
         Randall  Mays,   the  Chief   Financial   Officer  of  another  of  the
         stockholders of ATC, shall have been elected as directors of ATS;

                  (f) ATC shall have received from its counsel,  Vinson & Elkins
         L.L.P.,  a  favorable  opinion  (dated as of the  Closing  Date) to the
         effect that the Merger constitutes a reorganization  within the meaning
         of  Section  368 of the Code and that,  as a  consequence,  ATC and its
         stockholders will not recognize any gain or loss for federal income tax
         purposes as a result of consummation of the Merger,  and, in connection
         with such opinion, ATS shall have executed and delivered to ATC and its
         counsel a certificate substantially in the form of Exhibit I hereto and
         made a part hereof; and

                  (g) Either the CBS Merger  shall be  consummated  on the terms
         set forth in the CBS Merger Agreement, including execution and delivery
         of the ATS Separation  Agreement or the Tower  Distribution  shall have
         occurred.


                                    ARTICLE 8

                        TERMINATION, AMENDMENT AND WAIVER

         8.1 Termination.  This Agreement may be terminated at any time prior to
the Closing Date:

                  (a) by mutual consent of ATC and ATS; or

                  (b) by either ATS or ATC if any permanent  injunction,  decree
         or judgment by any Authority  preventing the consummation of the Merger
         shall have become final and nonappealable; or

                  (c) by ATC in the  event  (i)  ATC is not in  breach  of  this
         Agreement  and none of its  representations  or  warranties  shall have
         become  and  continue  to be untrue in a manner  that  would  cause the
         condition  set forth in Section  7.2(b) not to be  satisfied,  and (ii)
         either (A) the Merger has not been consummated prior to the Termination
         Date,  or  (B)  ATS  is in  breach  of  this  Agreement  or  any of its
         representations  or  warranties  shall have  become and  continue to be
         untrue  in a  manner  that  would be  reasonably  likely  to cause  the
         conditions set forth in Section 7.3(b) not to be satisfied,  and such a
         breach or untruth exists and is not capable of being cured, by and will
         prevent  or  delay  consummation  of  the  Merger  by  or  beyond,  the
         Termination Date; or

                  (d) by ATS in the  event  (i)  ATS is not in  breach  of  this
         Agreement  and none of its  representations  or  warranties  shall have
         become  and  continue  to be untrue in a manner  that  would

                                      -46-
<PAGE>

         cause the  condition  set forth in Section  7.3(b) not to be satisfied,
         and (ii)  either (A) the Merger has not been  consummated  prior to the
         Termination  Date, or (B) ATC is in breach of this  Agreement or any of
         ATC's  representations  or warranties shall have become and continue to
         be  untrue in a manner  that  would be  reasonably  likely to cause the
         conditions set forth in Section 7.2(b) not to be satisfied,  and such a
         breach or untruth exists and is not capable of being cured by, and will
         prevent  or  delay  consummation  of  the  Merger  by  or  beyond,  the
         Termination Date; or

                  (e)  by  ATS or ATC in  the  event  (i)  the  ATC  Stockholder
         Approval has not been  obtained  prior to the  Termination  Date,  (ii)
         neither the CBS Merger nor the Tower Distribution has occurred prior to
         the Termination  Date in the manner described in Section 6.21, or (iii)
         prior to the  Termination  Date,  any consent or approval  from the ARS
         stockholders  required to satisfy any of the conditions in Article 7 or
         otherwise to consummate the Merger has not been obtained.

         The right of ATS or ATC to terminate  this  Agreement  pursuant to this
Section shall remain  operative  and in full force and effect  regardless of any
investigation  made by or on behalf  of either  party,  any  Person  controlling
either  party or any of their  respective  Representatives  whether  prior to or
after the execution of this Agreement.

         8.2 Effect of Termination.

                  (a) Except as provided in Sections 6.1 (solely with respect to
         confidentiality),  6.3 and 6.15 and this Section and except as provided
         in Section  8.2(b),  in the event of the  termination of this Agreement
         pursuant to Section 8.1, or in the event the Merger shall not have been
         consummated  prior  to the end of  business  on the  Termination  Date,
         except as otherwise  provided in this  Section,  this  Agreement  shall
         forthwith  become  void,  there  shall be no  liability  on the part of
         either  party,  or any  of its  respective  shareholders,  officers  or
         directors,  to the other and all rights and obligations of either party
         shall cease; provided, however, that such termination shall not relieve
         either  party  from  liability  for any  willful  misrepresentation  or
         willful  breach of any of its  warranties,  covenants or agreements set
         forth in this Agreement.

                  (b)   Notwithstanding   anything  in  this  Agreement  to  the
         contrary,  including without  limitation the provisions of Section 9.4,
         in  the  event  this  Agreement  is  terminated  (a)  pursuant  to  the
         provisions of Section 8.1(e)(i),  then ATC acknowledges and agrees that
         ATS  shall be  entitled  to a  termination  fee in an  amount  equal to
         $15,000,000,  together  with  the  reasonable  out of  pocket  fees and
         expenses  (including  without  limitation  the reasonable out of pocket
         fees and expenses of  accountants,  attorneys,  financial  advisors and
         printers and all  registration  and other filing  fees),  not to exceed
         $1,000,000,  incurred by ATS in connection  with this Agreement and the
         Merger,  unless ATS has  notified  Fred R.  Lummis (or the then  acting
         Chairman of ATC, if not Mr. Lummis) or ATC is otherwise actually aware,
         at least five (5)  business  days in advance of the  Termination  Date,
         that the ATS  Registration  Statement has been declared  effective,  in
         which case ATS shall not be entitled to any  termination  fee,  expense
         reimbursement  or  other  payment  from  ATC,  or (b)  pursuant  to the
         provisions of Section  8.1(e)(ii) or (iii),  then ATS  acknowledges and
         agrees  that ATC shall be entitled  to a  termination  fee in an amount
         equal to  $15,000,000,  together with the reasonable out of pocket fees
         and expenses (including without limitation the reasonable out of pocket
         fees and expenses of  accountants,  attorneys,  financial  advisors and
         printers and all  registration  and other filing  fees),  not to exceed
         $1,000,000,  incurred by ATC in connection  with this Agreement and the
         Merger. The parties agree that, anything in Section 8.2(a), Section 9.4
         or elsewhere in this  Agreement to the contrary  notwithstanding,  such
         amount shall be a sole and exclusive remedy and constitute full


                                      -47-
<PAGE>

         payment for any and all damages suffered by ATS or ATC, as the case may
         be, by reason of the events referred to in the preceding sentence.  ATS
         and ATC agree in advance  that actual  damages  would be  difficult  to
         ascertain and that such  termination fee is a fair and equitable amount
         to be paid by ATC or by ATS in order to reimburse the other for damages
         sustained  due to the failure of the Merger to be  consummated  for the
         above-stated reasons.


                                    ARTICLE 9

                               GENERAL PROVISIONS

         9.1 Waivers; Amendments.  Changes in or additions to this Agreement may
be made,  or compli  ance  with any  term,  covenant,  agreement,  condition  or
provision  set forth herein may be omitted or waived  (either  generally or in a
particular  instance and either  retroactively or prospectively)  with, but only
with,  the  consent in writing of the  parties  hereto.  No delay on the part of
either  party at any time or times in the  exercise of any right or remedy shall
operate as a waiver thereof. Any consent may be given subject to satisfaction of
conditions  stated therein.  The failure to insist upon the strict provisions of
any  covenant,  term,  condition  or other  provision  of this  Agreement  or to
exercise  any right or remedy  thereunder  shall not  constitute a waiver of any
such  covenant,  term,  condition  or other  provision  thereof  or  default  in
connection  therewith.  The waiver of any  covenant,  term,  condition  or other
provision thereof or default thereunder shall not affect or alter this Agreement
in any other  respect,  and each and every  covenant,  term,  condition or other
provision of this  Agreement  shall,  in such event,  continue in full force and
effect,  except as so waived,  and shall be operative  with respect to any other
then existing or subsequent default in connection therewith.

         9.2 Fees, Expenses and Other Payments.  All costs and expenses incurred
in connection with this Agreement and the consummation of the Merger,  including
without  limitation fees and  disbursements of counsel,  financial  advisors and
accountants  incurred by the parties hereto,  shall be borne solely and entirely
by the party which has incurred such costs and expenses or which is  responsible
therefor under Applicable Law.

         9.3  Notices.  All  notices  and  other  communications  which  by  any
provision of this Agreement are required or permitted to be given shall be given
in writing and shall be deemed to have been  delivered  (a) three (3) days after
being mailed by  first-class  or express  mail,  postage  prepaid,  (b) the next
business  day when  sent  overnight  by  recognized  courier  service,  (c) upon
confirmation  when  sent by telex,  telegram,  telecopy  or other  form of rapid
transmission,  confirmed  by mailing  (by first class or express  mail,  postage
prepaid, or by recognized courier service) written confirmation at substantially
the same time as such rapid  transmission,  or (d) upon delivery when personally
delivered to the receiving party (which if other than an individual  shall be an
officer or other responsible party of the receiving party). All such notices and
communications shall be mailed, sent or delivered as follows:

                  (a)      If to ATS:

                  116 Huntington Avenue
                  Boston, Massachusetts 02116
                  Attention:   Joseph L. Winn, Chief Financial Officer
                  Telecopier No.:  (617) 375-7575

                                      -48-
<PAGE>


                  with a copy to:

                  Sullivan & Worcester LLP
                  One Post Office Square
                  Boston, Massachusetts 02109
                  Attention:  Norman A. Bikales, Esq.
                  Telecopier No.:  (617) 338-2880

                  (b)      If to ATC:

                  3411 Richmond Avenue,
                  Suite 400
                  Houston, Texas 77046
                  Attention: Marty L. Jimmerson, Chief Financial Officer
                  Telecopier No.:   (713) 629-1189

                  with a copy to:

                  Vinson & Elkins L.L.P.
                  1001 Fannin
                  Suite 2300
                  Houston, Texas 70002-6170
                  Attention: Bruce C. Herzog, Esq.
                  Telecopier No.:  (713) 615-5946

or to such other person(s),  telex or facsimile  number(s) or address(es) as the
party to receive any such communication or notice may have designated by written
notice to the other party given in accordance with this Section.

         9.4  Specific  Performance;  Other  Rights  and  Remedies.  Each  party
recognizes and agrees that in the event the other party should refuse to perform
any of its  obligations  under this  Agreement or any Collateral  Document,  the
remedy at law would be inadequate and agrees that for breach of such provisions,
each party shall,  in addition to such other  remedies as may be available to it
at law or in equity, except as otherwise provided in Section 8.2(b), be entitled
to  injunctive  relief  and to  enforce  its  rights by an action  for  specific
performance to the extent  permitted by Applicable Law. Each party hereby waives
any  requirement  for  security  or the  posting of any bond or other  surety in
connection  with any temporary or permanent  award of  injunctive,  mandatory or
other equitable  relief.  Except as otherwise  provided in Section 8.2,  nothing
herein  contained  shall be construed as prohibiting  either party from pursuing
any other remedies  available to it pursuant to the provisions of this Agreement
or Applicable Law for a breach by the other party,  including without limitation
the recovery of damages,  including,  to the extent awarded in any Legal Action,
punitive,  incidental and consequential  damages  (including  without limitation
damages for  diminution in value and loss of  anticipated  profits) or any other
measure of damages permitted by Applicable Law.

         9.5  Severability.  If any term or provision of this Agreement shall be
held or deemed  to be, or shall in fact be,  invalid,  inoperative,  illegal  or
unenforceable  as  applied  to  any  particular  case  in  any  jurisdiction  or
jurisdictions,  or in  all  jurisdictions  or  in  all  cases,  because  of  the
conflicting of any provision with any  constitution or statute or rule of public
policy or for any other reason,  such circumstance  shall not have the effect of
rendering the provision or provisions in question invalid, inoperative,  illegal
or 

                                      -49-
<PAGE>


unenforceable in any other  jurisdiction or in any other case or circumstance or
of  rendering  any other  provision  or  provisions  herein  contained  invalid,
inoperative,  illegal or  unenforceable to the extent that such other provisions
are not themselves actually in conflict with such constitution,  statute or rule
of public policy, but this Agreement shall be reformed and construed in any such
jurisdiction or case as if such invalid,  inoperative,  illegal or unenforceable
provision had never been contained herein and such provision reformed so that it
would be valid,  operative and  enforceable to the maximum  extent  permitted in
such jurisdiction or in such case.  Notwithstanding the foregoing,  in the event
of any such  determination  the  effect  of which is to  affect  materially  and
adversely either party, the parties shall negotiate in good faith to modify this
Agreement  so as to effect  the  original  intent of the  parties  as closely as
possible to the fullest  extent  permitted by  Applicable  Law in an  acceptable
manner to the end that the  Transactions  are fulfilled and  consummated  to the
maximum extent possible.

         9.6   Counterparts.   This   Agreement   may  be  executed  in  several
counterparts,  each of  which  shall be  deemed  an  original,  but all of which
together shall constitute one and the same  instrument,  binding upon all of the
parties. In pleading or proving any provision of this Agreement, it shall not be
necessary to produce more than one of such counterparts.

         9.7 Section Headings.  The headings contained in this Agreement are for
reference  purposes  only  and  shall  not in any  way  affect  the  meaning  or
interpretation of this Agreement.

         9.8  Governing  Law. The  validity,  interpretation,  construction  and
performance of this Agreement  shall be governed by, and construed in accordance
with,  the  applicable  laws of the United States of America and the laws of the
State of New York  applicable to contracts made and performed in such State and,
in any event,  without giving effect to any choice or conflict of laws provision
or rule that would cause the  application  of domestic  substantive  laws of any
other jurisdiction, except to the extent that the DCL or other laws of the State
of Delaware shall be applicable.

         9.9 Further Acts.  Each party agrees that at any time, and from time to
time, before and after the consummation of the transactions contemplated by this
Agreement,  it  will do all  such  things  and  execute  and  deliver  all  such
Collateral  Documents and other assurances,  as the other party reasonably deems
necessary or desirable  in order to carry out the terms and  conditions  of this
Agreement  and  the  transactions  contemplated  hereby  or  to  facilitate  the
enjoyment of any of the rights created hereby or to be created hereunder.

         9.10 Entire Agreement. This Agreement (together with the ATC Disclosure
Schedule,  the ATS Disclosure  Schedule,  the Exhibits and the other  Collateral
Documents delivered or to be delivered in connection  herewith)  constitutes the
entire  agreement of the parties with respect to the subject  matter  hereof and
supersedes all prior agreements, arrangements,  covenants, promises, conditions,
undertakings,   inducements,   representations,   warranties  and  negotiations,
expressed or implied, oral or written,  between the parties, with respect to the
subject matter hereof.  Each of the parties is a sophisticated legal entity that
was advised by experienced counsel and, to the extent it deemed necessary, other
advisors  in  connection  with  this  Agreement.  Each  of  the  parties  hereby
acknowledges  that (a) neither of the parties has relied or will rely in respect
of this Agreement or the transactions  contemplated  hereby upon any document or
written or oral information  previously  furnished to or discovered by it or its
representatives,  other than this  Agreement  (or such of the  foregoing  as are
delivered at the Closing,  (b) there are no  covenants  or  agreements  by or on
behalf of either party or any of its  respective  Affiliates or  representatives
other  than  those  expressly  set forth in this  Agreement  and the  Collateral
Documents,  and (c) the parties'  respective rights and obligations with respect
to this Agreement and the events giving rise thereto will be solely as set forth
in this Agreement and the Collateral Documents.  WITHOUT LIMITING THE GENERALITY
OF THE FOREGOING, EACH PARTY

                                      -50-
<PAGE>



HERETO AGREES THAT, EXCEPT FOR THE REPRESENTATIONS  AND WARRANTIES  CONTAINED IN
THIS  AGREEMENT,  NEITHER  OF THE  PARTIES  MAKES ON BEHALF  OF  ITSELF  AND ITS
DIRECTORS, OFFICERS, STOCKHOLDERS AND OTHER AFFILIATES ANY OTHER REPRESENTATIONS
OR WARRANTIES,  AND EACH HEREBY  DISCLAIMS ON BEHALF OF ITSELF AND ITS OFFICERS,
DIRECTORS,  STOCKHOLDERS  AND  OTHER  AFFILIATES  ANY OTHER  REPRESENTATIONS  OR
WARRANTIES MADE BY ITSELF OR ANY OF ITS OFFICERS, DIRECTORS,  EMPLOYEES, AGENTS,
FINANCIAL  AND LEGAL  ADVISORS  OR OTHER  REPRESENTATIVES,  WITH  RESPECT TO THE
EXECUTION  AND  DELIVERY  OF THIS  AGREEMENT  OR THE  TRANSACTIONS  CONTEMPLATED
HEREBY,  NOTWITHSTANDING  THE DELIVERY OR DISCLOSURE TO THE OTHER OR THE OTHER'S
REPRESENTATIVES  OF ANY  DOCUMENTATION OR OTHER  INFORMATION WITH RESPECT TO ANY
ONE OR MORE OF THE FOREGOING.

         9.11 Assignment. This Agreement shall not be assignable by either party
and any such  assignment  shall be null and void,  except that it shall inure to
the benefit of and by binding upon any successor to either party by operation of
law,  including by way of merger,  consolidation or sale of all or substantially
all of its assets.

         9.12  Parties in  Interest.  This  Agreement  shall be binding upon and
inure  solely to the  benefit of each  party,  and  nothing  in this  Agreement,
express or implied,  is  intended to or shall  confer upon any Person any right,
benefit or remedy of any nature whatsoever under or by reason of this Agreement,
except as otherwise provided in Sections 6.8, 6.9(b), 6.9(c), 6.10 and 8.11.

         9.13  Non-Survival  of  Representations,   Warranties,   Covenants  and
Agreements.  Except for damages or other remedies  attributable to or based upon
fraud, willful or intentional misrepresentation or willful or intentional breach
of warranty,  covenant or agreement,  none of the  representations,  warranties,
covenants and agreements in this Agreement  shall survive the Merger,  and after
effectiveness  of the Merger neither party nor any of its  respective  officers,
directors  or  stockholders  shall  have any  further  obligation  with  respect
thereto.  This Section  shall not limit any covenant or agreement of the parties
which by its terms contemplates performance after the Effective Time.

         9.14 Mutual Drafting. This Agreement is the result of the joint efforts
of the  parties,  and each  provision  hereof  has been  subject  to the  mutual
consultation,  negotiation  and  agreement  of the parties and there shall be no
construction  against  either  party based on any  presumption  of that  party's
involvement in the drafting thereof.


                      [SIGNATURES APPEAR ON FOLLOWING PAGE]

                                      -51-


<PAGE>



         IN WITNESS WHEREOF,  the parties have executed or caused this Agreement
to be executed by their respective  officers thereunto duly authorized as of the
date first written above.

                                     American Tower Systems Corporation


                                     By: /s/ Joseph L. Winn
                                          Name:  Joseph L. Winn
                                          Title:    Chief Financial Officer

                                     American Tower Corporation


                                     By: /s/  Fred R. Lummis
                                          Name:  Fred R. Lummis
                                          Title:   President






                                      -52-


<PAGE>




                                                                      APPENDIX A

                                   DEFINITIONS

         Affiliate,  Affiliated shall mean, with respect to any Person,  (a) any
other Person at the time  directly or indirectly  controlling,  controlled by or
under direct or indirect  common control with such Person,  (b) any other Person
of which such Person at the time owns, or has the right to acquire,  directly or
indirectly,  ten  percent  (10%) or more of any  class of the  capital  stock or
beneficial  interest,  (c) any other Person  which at the time owns,  or has the
right to acquire, directly or indirectly, ten percent (10%) or more of any class
of the capital  stock or beneficial  interest of such Person,  (d) any executive
officer or director of such Person,  (e) with respect to any partnership,  joint
venture or similar Entity,  any general partner thereof,  and (f) when used with
respect  to an  individual,  shall  include  any  member  of  such  individual's
immediate family or a family trust.

         Agreement shall mean this Agreement as originally in effect, including,
unless the context  otherwise  specifically  requires,  this Appendix A, the ATC
Disclosure Schedule, the ATS Disclosure Schedule and all exhibits hereto, and as
any of the same may from  time to time be  supplemented,  amended,  modified  or
restated in the manner herein or therein provided.

         Aggregate  Merger Shares shall mean the number  obtained by solving the
following equation for "x":

                  x =  (.5384615)  multiplied  by y,  where "y" is the number of
                  shares of ATS Common Stock determined on a Fully-Diluted Basis
                  immediately  prior to the Effective  Time.  Thus, in the event
                  there  were no  Dissenting  Shares,  the  number of  Aggregate
                  Merger  Shares  would  equal  35% of the sum of the  Aggregate
                  Merger  Shares and the  number of shares of ATS  Common  Stock
                  determined on a Fully-Diluted Basis.

         Alternative  Transaction  shall mean,  with  respect to any  Person,  a
transaction  or series of related  transactions  (other  than the  Transactions)
resulting in or reasonably likely to result in (i) any change of control of such
Person,  (ii) any merger,  consolidation  or other business  combination of such
Person,  regardless  of whether such Person is the  surviving  Entity unless the
surviving  Entity remains  obligated  under this Agreement to the same extent as
such  Person  was,  (iii)  any  tender  offer  or  exchange  offer  for,  or any
acquisitions  of,  any  securities  of such  Person,  (iv)  any  sale  or  other
disposition  of all or any  substantial  part of the assets or  business of such
Person,  (v) any issue or sale, or any  agreement to issue or sell,  any capital
stock,  Convertible Securities,  Option Securities or other equity securities by
such Person,  or (vi) any issue,  sale,  transfer,  pledge,  assignment or other
conveyance  or any  agreement  to  issue,  sell,  transfer,  pledge,  assign  or
otherwise  convey,  any  capital  stock,  such  Convertible  Securities,  Option
Securities or other equity securities of such Person.

         Applicable Law shall mean any Law of any Authority, whether domestic or
foreign,  including  without  limitation  the  FCA  and all  federal  and  state
securities and  Environmental  Laws, to which a Person is subject or by which it
or any of its business or operations is subject or any of its property or assets
is bound.

         ARS shall have the meaning given to it in the fourth Whereas paragraph.

         ARS Credit  Agreements shall mean the two credit agreements of ARS with
its lending banks and other financial institutions.

                                       A-1


<PAGE>



         ARS  Cumulative  Preferred  Stock  shall  mean  the 11 3/8%  Cumulative
Exchangeable Preferred Stock, par value $.01 per share, of ARS.

         ARS Preferred Certificate shall have the meaning given to it in Section
5.23(b).

         ATC shall have the meaning given to it in the Preamble.

         ATC Affiliate  Agreements shall have the meaning given to it in Section
6.24.

         ATC Assets shall have the meaning given to it in Section 4.4(a).

         ATC Business shall have the meaning given to it in Section 4.4(a).

         ATC Business Description shall mean the business description of ATC set
forth in the ATS Prospectus.

         ATC Common Stock shall have the meaning given to it in Section 3.1(b).

         ATC Conditions shall have the meaning given to it in Section 6.17.

         ATC Disclosure Schedule shall mean the ATC Disclosure Schedule dated as
of the date of this Agreement delivered by ATC to ATS.

         ATC Employees shall have the meaning given it in Section 4.14.

         ATC Financial  Statements shall have the meaning given to it in Section
4.2.

         ATC Governmental  Authorizations  shall have the meaning given to it in
Section 4.6(a).

         ATC Option(s)  shall have the meanings  given to those terms in Section
6.10.

         ATC  Preferred  Stock  shall  have the  meaning  given to it in Section
3.1(d).

         ATC  Private  Authorization(s)  shall have the  meaning  given to it in
Section 4.5.

         ATC Required Vote shall have the meaning given to it in Section 4.21.

         ATC Share(s) shall have the meanings given to them in Section 3.1(b).

         ATC Stockholder  Approval shall have the meaning given to it in Section
6.12.

         ATC  Stockholder  Information  shall  have the  meaning  given to it in
Section 6.13(b)

         ATC Stockholders  Meeting shall have the meaning given to it in Section
6.12.

         ATC's  knowledge  (or words of  similar  import)  shall mean the actual
knowledge of ATC or any ATC director or officer, as such knowledge exists on the
date of this Agreement,  after reasonable  review of appropriate ATC records and
after reasonable inquiry of appropriate ATC employees.

                                       A-2


<PAGE>



         ATS shall have the meaning given to it in the Preamble.

         ATS Assets shall have the meaning given to it in Section 5.4(a).

         ATS Business shall have the meaning given to it in Section 5.4(a).

         ATS Existing Restated Certificate shall have the meaning given to it in
Section 2.5.

         ATS Class A Common Stock shall have the meaning  given to it in Section
3.1(b).

         ATS Class B Common Stock shall mean the Class B Common Stock, par value
$.01 per share, of ATS.

         ATS Common Stock shall have the meaning given to it in Section 3.1(b).

         ATS Conditions shall have the meaning given to it in Section 6.17.

         ATS Disclosure Schedule shall mean the ATS Disclosure Schedule dated as
of the date of this Agreement delivered by ATS to ATC.

         ATS Employees shall have the meaning given it in Section 5.13.

         ATS Financial  Statements shall have the meaning given to it in Section
5.2

         ATS Governmental  Authorizations  shall have the meaning given to it in
Section 5.6(a)

          ATS Information  Statement shall mean the Information Statement draft,
dated  December  12,  1997,  describing  the  business of ATS and certain  other
matters heretofore delivered by ATS to ATC.

         ATS'  knowledge  (or words of  similar  import)  shall  mean the actual
knowledge of any director or executive  officer of ATS, as such knowledge exists
on the date of this  Agreement,  after  reasonable  review  of  appropriate  ATS
records and after reasonable inquiry of appropriate ATS employees.

         ATS  Noncompetition  Agreements  shall have the meaning  given to it in
Section 7.2(i).

         ATS Option(s)  shall have the meanings  given to those terms in Section
6.10.

         ATS  Private  Authorizations  shall  have  the  meaning  given to it in
Section 5.5.

         ATS Private Placement shall mean the issue and sale by ATS of shares of
ATS Class A Common  Stock to certain  officers  and  directors  of ATS (or their
Affiliates) for an aggregate  consideration of not more than $80.0 million, at a
per share price of not less than $9.00,  all as described in the ATS Information
Statement.

         ATS Prospectus shall have the meaning given to it in Section 6.13(b).

         ATS Registration Rights Agreement shall have the meaning given to it in
Section 6.17.


                                       A-3


<PAGE>



         ATS  Registration  Statement  shall  have  the  meaning  given to it in
Section 6.13(a).

         ATS Restated  Certificate shall have the meaning given to it in Section
2.5.

         ATS  Separation  Agreement  shall  mean the  agreement  referred  to in
Section  6.17 of the CBS  Merger  Agreement  and  which  shall  incorporate  the
provisions  of Section 6.17,  6.18 and 6.19 of the CBS Merger  Agreement as they
exist on the date  hereof or as they may be  amended  in a manner  that does not
increase materially the obligations and liabilities of ATS.

         ATS Voting Agreement shall have the meaning give to it in Section 6.11.

         ATSI shall mean American  Tower Systems,  Inc., a Delaware  corporation
which is wholly-owned by ATS and which conducts directly or through Subsidiaries
substantially all of the ATS Business and owns directly or through  Subsidiaries
substantially all of the ATS Assets.

         Authority shall mean any governmental or quasi-governmental  authority,
whether  administrative,  executive,  judicial,  legislative  or  other,  or any
combination   thereof,   including  without   limitation  any  federal,   state,
territorial,   county,   municipal  or  other   government  or  governmental  or
quasi-governmental agency, arbitrator,  authority,  board, body, branch, bureau,
or comparable Person, whether domestic or foreign,  including without limitation
the FCC.

         Benefit  Arrangement  shall  mean,  with  respect  to any  Person,  any
material benefit arrangement that is not a Plan, including (a) any employment or
consulting  agreement,  (b) any arrangement  providing for insurance coverage or
workers'  compensation  benefits,  (c) any  incentive  bonus or  deferred  bonus
arrangement,  (d) any arrangement providing termination allowance,  severance or
similar  benefits,   (e)  any  equity   compensation   plan,  (f)  any  deferred
compensation plan, and (g) any compensation policy and practice, but only to the
extent that it covers or relates to any officer, employee,  individual or Entity
involved  in the  ownership  and  operation  of the assets of such Person or the
conduct of the business of such Person.

         CBS Merger shall mean the merger of R Acquisition  Corp. ("CBS Sub"), a
Delaware  subsidiary  wholly-owned  by CBS  Corporation  (formerly  Westinghouse
Electric Corporation), a Pennsylvania corporation ("CBS"), with and into ARS, on
the terms set forth in an  Agreement  and Plan of Merger,  dated as of September
19,  1997,  by and among ARS, CBS and CBS Sub, as the same has  heretofore  been
amended  or as it  may  from  time  to  time  be  hereafter  amended,  modified,
supplemented  and  restated in a manner that does not  increase  materially  the
obligations and liabilities of ATS (as so amended,  modified,  supplemented  and
restated, the "CBS Merger Agreement").

         Certificate shall have the meaning given to it in Section 3.1(i).

         Certificate  of Merger  shall have the  meaning  given to it in Section
2.3.

         Claims shall mean any and all debts, liabilities,  obligations, losses,
damages,  deficiencies,  assessments  and  penalties,  together  with all  Legal
Actions, pending or threatened, claims and judgments of whatever kind and nature
relating  thereto,  and all fees, costs,  expenses and disbursements  (including
without  limitation  reasonable  attorneys'  and  other  legal  fees,  costs and
expenses) relating to any of the foregoing.

         Closing shall have the meaning given to it in Section 2.2.


                                       A-4


<PAGE>



         Closing Date shall have the meaning given to it in Section 2.2.

         COBRA shall mean the Consolidated Omnibus Budget  Reconciliation Act of
1985,  as  amended,  as set  forth  in  Section  4980B of the Code and Part 6 of
Subtitle B of Title I of ERISA.

         Code shall mean the Internal  Revenue  Code of 1986,  and the rules and
regulations  thereunder,  all as from time to time in effect,  or any  successor
law,  rules or  regulations,  and any  reference to any  statutory or regulatory
provision  shall be deemed  to be a  reference  to any  successor  statutory  or
regulatory provision.

         Collateral Documents shall mean the ATC Affiliate  Agreements,  the ATS
Information  Statement,   the  ATS  Prospectus,   the  ATS  Registration  Rights
Agreement, the ATS Registration Statement, the ATS Restated Certificate, the ATS
Voting   Agreement,   the  Certificate  of  Merger  and  any  other   agreement,
certificate,  contract,  instrument, notice, opinion or other document delivered
pursuant to the provisions of this Agreement.

         Commission shall mean the Securities and Exchange  Commission and shall
include any successor Authority.

         Confidential  Information shall have the meaning given to it in Section
6.1(a).

         Continued  Employees  shall  have the  meaning  given to it in  Section
6.9(b).

         Contract,  Contractual  Obligation  shall  mean,  with  respect  to any
Person, any agreement,  arrangement,  commitment, contract, covenant, indemnity,
undertaking  or other  obligation or liability  which  involves the ownership or
operation  of the assets of such Person or the  conduct of the  business of such
Person.

         Control (including the terms  "controlled,"  "controlled by" and "under
common control with") means the possession, directly or indirectly or as trustee
or executor,  of the power to direct or cause the direction of the management or
policies of a Person,  or the disposition of such Person's assets or properties,
whether through the ownership of stock, equity or other ownership,  by contract,
arrangement or understanding,  or as trustee or executor,  by contract or credit
arrangement or otherwise.

         Convertible Securities shall mean any evidences of indebtedness, shares
of capital  stock  (other than  common  stock) or other  securities  directly or
indirectly  convertible into or exchangeable for shares of common stock, whether
or not the right to convert or exchange thereunder is immediately exercisable or
is conditioned  upon the passage of time, the  occurrence or  non-occurrence  or
existence or non-existence of some other Event, or both.

         DCL shall have the meaning given to it in Section 2.1.

         Distribution   shall  mean,  with  respect  to  any  Person,   (a)  the
declaration or payment of any dividend (except dividends payable in common stock
of such Person) on or in respect of any shares of any class of capital  stock of
such Person or any shares of capital stock of any  Subsidiary  owned by a Person
other than such Person or a Subsidiary,  (b) the  purchase,  redemption or other
retirement  of any  shares of any class of capital  stock of such  Person or any
shares of capital stock of any Subsidiary of such Person owned by a Person other
than such Person or a Subsidiary of such Person,  and (c) any other distribution
on or in respect of any shares of any class of capital  stock of such  Person or
any shares of capital  stock of any  Subsidiary of such Person owned by a Person
other than such Person or a Subsidiary of such Person.

         D&O Questionnaire shall have the meaning given to it in Section 6.8(c).

                                       A-5


<PAGE>



         Effective Time shall have the meaning given to it in Section 2.3.

         Employment  Arrangement  shall mean,  with  respect to any Person,  any
employment,  consulting,  retainer,  severance or similar  contract,  agreement,
plan,  arrangement or policy (exclusive of any which is terminable within thirty
(30) days  without  liability,  penalty or payment of any kind by such Person or
any  Affiliate),  or providing for severance,  termination  payments,  insurance
coverage  (including  any  self-insured  arrangements),   workers  compensation,
disability benefits, life, health, medical, dental or hospitalization  benefits,
supplemental unemployment benefits,  vacation or sick leave benefits, pension or
retirement benefits or for deferred compensation, profit-sharing, bonuses, stock
options,  stock  purchase or  appreciation  rights or other  forms of  incentive
compensation  or  post-retirement  insurance,  compensation  or  post-retirement
insurance, compensation or benefits, or any collective bargaining or other labor
agreement,  whether or not any of the foregoing is subject to the  provisions of
ERISA, but only to the extent that it covers or relates to any officer, employee
or other  Person  involved in the  ownership  or  operation of the assets or the
conduct of the business of such Person.

         Encumber  shall  mean  to  suffer,  accept,  agree  to  or  permit  the
imposition of a Lien.

         Entity shall mean any corporation,  firm, unincorporated  organization,
association,  partnership,  limited  liability  company,  trust  (inter vivos or
testamentary),  estate of a deceased, insane or incompetent individual, business
trust,  joint stock  company,  joint  venture or other  organization,  entity or
business,  whether acting in an individual,  fiduciary or other capacity, or any
Authority.

         Environmental Law shall mean any Law relating to or otherwise  imposing
liability or  standards of conduct  concerning  pollution or  protection  of the
environment,   including   without   limitation   Laws  relating  to  emissions,
discharges,  releases or  threatened  releases of  Hazardous  Materials or other
chemicals or  industrial  pollutants,  substances,  materials or wastes into the
environment (including,  without limitation,  ambient air, surface water, ground
water,  mining or reclamation or mined land, land surface or subsurface  strata)
or otherwise relating to the manufacture,  processing, generation, distribution,
use, treatment, storage, disposal, cleanup, transport or handling of pollutants,
contaminants,  chemicals or industrial, toxic or hazardous substances, materials
or wastes. Environmental Laws shall include without limitation the Comprehensive
Environmental  Response,  Compensation and Liability Act (42 U.S.C. Section 6901
et seq.), the Hazardous Material  Transportation Act (49 U.S.C.  Section 1801 et
seq.),  the Resource  Conservation  and Recovery Act (42 U.S.C.  Section 6901 et
seq.), the Federal Water Pollution Control Act (33 U.S.C. Section 1251 et seq.),
the Clean Air Act (42 U.S.C. Section 7401 et seq.), the Toxic Substances Control
Act (15 U.S.C. Section 2601 et seq.), the Occupational Safety and Health Act (29
U.S.C.  Section 651 et seq.), the Federal Insecticide  Fungicide and Rodenticide
Act (7  U.S.C.  Section  136 et  seq.),  and  the  Surface  Mining  Control  and
Reclamation  Act of 1977 (30 U.S.C.  Section  1201 et seq.),  and any  analogous
federal,   state,  local  or  foreign,  Laws,  and  the  rules  and  regulations
promulgated  thereunder  as in effect on the date hereof or on the Closing Date,
as applicable,  and any reference to any statutory or regulatory provision shall
be deemed to be a reference to any successor statutory or regulatory provision.

         Environmental Permit shall mean any Governmental Authorization required
by or pursuant to any Environmental Law.

         ERISA shall mean the Employee  Retirement  Income Security Act of 1974,
and the rules and regulations thereunder, all as from time to time in effect, or
any successor law, rules or  regulations,  and any reference to any statutory or
regulatory  provision  shall  be  deemed  to be a  reference  to  any  successor
statutory or regulatory provision.

                                       A-6


<PAGE>


         ERISA Affiliate shall mean, with respect to any Person,  any individual
or Entity that is treated as a single  employer with such Person under  Sections
414(b), (c), (m) or (o) of the Code or Section 4001(b)(1) of ERISA.

         Event  shall  mean the  existence  or  occurrence  of any act,  action,
activity,  circumstance,  condition,  event,  fact,  failure  to act,  omission,
incident or practice, or any set or combination of any of the foregoing.

         Exchange Act shall mean the  Securities  Exchange Act of 1934,  and the
rules and  regulations  thereunder,  all as from time to time in effect,  or any
successor  law,  rules or  regulations,  and any  reference to any  statutory or
regulatory  provision  shall  be  deemed  to be a  reference  to  any  successor
statutory or regulatory provision.

         Exchange Ratio shall have the meaning given to it in Section 3.1(b).

         FCA  shall  mean the  Communications  Act of 1934,  and the  rules  and
regulations  thereunder,  all as from time to time in effect,  or any  successor
law,  rules or  regulations,  and any  reference to any  statutory or regulatory
provision  shall be deemed  to be a  reference  to any  successor  statutory  or
regulatory provision.

         FCC shall mean the Federal Communications  Commission and shall include
any successor Authority.

         Final  Order  shall  mean,  with  respect to any  Authority,  including
without  limitation  the FCC, one with respect to which no appeal,  no stay,  no
petition or application for rehearing, reconsideration,  review or stay, whether
on motion of the applicable Authority or other Person or otherwise, and no other
Legal Action contesting such consent or approval, is in effect or pending and as
to  which  the  time or  deadline  for  filing  any  such  appeal,  petition  or
application  or other Legal  Action has expired or, if filed,  has been  denied,
dismissed or  withdrawn,  and the time or deadline for  instituting  any further
Legal Action has expired.

         Fully-Diluted Basis shall mean, when applied to the ATC Common Stock or
the ATS  Common  Stock,  the total  number of shares of the issuer of such stock
that are outstanding as of the date of determination plus, without  duplication,
the total  number of all shares  issuable in respect of  securities  convertible
into or exchangeable for ATC Common Stock or ATS Common Stock (excluding the ATS
Common Stock that may be issued upon exchange of membership  interests issued in
Communications  System  Development,  LLC,  but  including  in both  Convertible
Securities), as the case may be, or issuable upon exercise of stock appreciation
rights  or  options,  warrants  and other  irrevocable  rights  to  purchase  or
subscribe  for ATC  Common  Stock  or ATS  Common  Stock,  as the  case  may be,
including Option Securities.  Without limiting the foregoing,  the parties agree
that,  if the  Tower  Distribution  occurs  before  the  CBS  Merger,  the  term
"Fully-Diluted  Basis" would take into  account any  Convertible  Securities  or
Option Securities that ATS or the Surviving Corporation may be required to issue
upon consummation of the Merger.

         GAAP shall mean generally accepted  accounting  principles applied on a
consistent  basis,  (i) as set forth in  Opinions of the  Accounting  Principles
Board of the American Institute of Certified Public Accountants ("AICPA") and/or
in statements of the Financial Accounting Standards Board that are applicable in
the  circumstances  as of the date in question,  and (ii) when not  inconsistent
with such opinions and statements,  as set forth in other AICPA publications and
guidelines  that otherwise arise by custom for the particular  industry,  all as
the same shall exist on the date of this Agreement.

         Gearon  Transaction  shall  mean the  merger of Gearon & Co.,  Inc.,  a
Georgia corporation ("Gearon"), with and into ATSI, pursuant to an Agreement and
Plan of Merger (the "Gearon Merger  Agreement"),  dated 

                                       A-7


<PAGE>



as of November 21, 1997, by and among ATS,  ATSI,  Gearon and J. Michael  Gearon
Jr.,  as the same  has may from  time to time be  hereafter  amended,  modified,
supplemented  and  restated  in a manner  which  would not have any  significant
adverse effect on ATS (as so amended,  modified,  supplemented and restated, the
"Gearon Merger Agreement").

         Governmental Authorizations shall mean, with respect to any Person, all
approvals,   concessions,   consents,  franchises,   licenses,  permits,  plans,
registrations  and other  authorizations  of all Authorities,  including without
limitation   the  United  States  Forest   Service  and  the  Federal   Aviation
Administration,  in connection  with the ownership or operation of the assets or
the conduct of the business of such Person.

         Governmental  Filings shall mean all filings,  including  franchise and
similar Tax  filings,  and the payment of all fees,  assessments,  interest  and
penalties associated with such filings, with all Authorities.

         Hart-Scott-Rodino Act shall mean the Hart-Scott-Rodino  Improvement Act
of 1976, as from time to time in effect, or any successor law, and any reference
to any  statutory  provision  shall be deemed to be a reference to any successor
statutory provision.

         Hazardous  Materials  shall mean and include any  substance,  material,
waste, constituent, compound, chemical, natural or man-made element (in whatever
state  of  matter):  (a)  the  presence  of  which  requires   investigation  or
remediation  under any  Environmental  Law,  (b) that is defined as a "hazardous
waste" or "hazardous  substance" under any Environmental Law; (c) that is toxic,
explosive,   corrosive,   etiologic,   flam  mable,   infectious,   radioactive,
carcinogenic,  mutagenic  or  otherwise  hazardous  and is  regulated  by any ap
plicable  Authority pursuant to any Environmental Law; (d) the presence of which
on the real property owned or leased by such Person causes or threatens to cause
a nuisance  upon any such real  property or to adjacent  properties  or poses or
threatens  to pose a hazard to the  health or safety of  persons on or about any
such  real  property;  or (e)  that  contains  gasoline,  diesel  fuel or  other
petroleum  hydrocarbons,  or any by-products or fractions thereof,  natural gas,
polychlorinated  biphenyls  ("PCBs") and PCB-containing  equipment,  radioactive
material, lead, asbestos or asbestos-containing  materials, or urea formaldehyde
foam insulation.

         Indebtedness  shall mean,  with  respect to any Person,  (a) all items,
except  items of  capital  stock or of  surplus  or of  general  contingency  or
deferred tax reserves or any minority  interest in any Subsidiary of such Person
to the extent such interest is treated as a liability with indeterminate term on
the  consolidated  balance sheet of such Person,  which in accordance  with GAAP
would be included in  determining  total  liabilities  as shown on the liability
side of a balance sheet of such Person, (b) all obligations  secured by any Lien
to which any property or asset owned or held by such Person is subject,  whether
or not the obligation  secured  thereby shall have been assumed,  and (c) to the
extent not  otherwise  included,  all  Contractual  Obligations  of such  Person
constituting  capitalized leases and all obligations of such Person with respect
to Leases constituting part of a sale and leaseback arrangement.

         Indebtedness for Money Borrowed shall mean, with respect to any Person,
money borrowed and Indebtedness represented by notes payable and drafts accepted
representing   extensions  of  credit,  all  obligations   evidenced  by  bonds,
debentures,  notes or other similar instruments, the maximum amount currently or
at any time thereafter  available to be drawn under all  outstanding  letters of
credit  issued  for the  account of such  Person,  all  Indebtedness  upon which
interest  charges are  customarily  paid by such  Person,  and all  Indebtedness
(including capitalized lease obligations and purchase money Indebtedness) issued
or assumed as full or partial  payment for property or services,  whether or not
any such notes, drafts,  obligations or Indebtedness  represent Indebtedness for
Money Borrowed,  but shall not include (a) trade payables,  (b) expenses accrued
in the ordinary course of business,  (c) customer  advance payments and customer
deposits

                                       A-8


<PAGE>



received in the ordinary course of business, or (d) conditional sales agreements
not prohibited by the terms of this Agreement.

         Indemnified Party shall have the meaning given to it in Section 6.8(b).

         Intangible  Assets shall mean all assets and property  lacking physical
properties the evidence of ownership of which must  customarily be maintained by
independent  registration,  documentation,  certification,  recordation or other
means,  and  shall  include,   without  limitation,   concessions,   copyrights,
franchises,  license, patents, permits, service marks, trademarks,  trade names,
and applications with respect to any of the foregoing, technology and know-how.

         Law shall mean any (a) administrative,  judicial,  legislative or other
action,  code,  consent  decree,  constitution,  decree,  directive,  enactment,
finding, law, injunction,  interpretation,  judgment,  order, ordinance,  policy
statement, proclamation,  promulgation,  regulation,  requirement, rule, rule of
law,  rule of  public  policy,  settlement  agreement,  statute,  or writ of any
Authority, domestic or foreign; (b) the common law, or other legal precedent; or
(c)  arbitrator's,   mediator's  or  referee's  award,   decision,   finding  or
recommendation.

         Lease  shall mean any lease of  property,  whether  real,  personal  or
mixed, and all amendments thereto.

         Legal  Action  shall  mean,  with  respect to any  Person,  any and all
litigation   or   legal   or   other   actions,   arbitrations,   counterclaims,
investigations, proceedings, requests for material information by or pursuant to
the  order of any  Authority  or  suits,  at law or in  arbitration,  equity  or
admiralty,  whether or not  purported  to be  brought on behalf of such  Person,
affecting such Person or any of such Person's business, property or assets.

         Lien shall mean any of the  following:  mortgage;  lien  (statutory  or
other);  or other security  agreement,  arrangement or interest;  hypothecation,
pledge  or  other  deposit  arrangement;  assignment;  charge;  levy;  executory
seizure;   attachment;   garnishment;   encumbrance   (including  any  easement,
exception,  reservation or limitation,  right of way, and the like); conditional
sale,  title  retention  or other  similar  agreement,  arrangement,  device  or
restriction;   preemptive  or  similar  right;  any  financing  lease  involving
substantially  the same economic  effect as any of the foregoing;  the filing of
any financing  statement under the Uniform  Commercial Code or comparable law of
any  jurisdiction;  restriction on sale,  transfer,  assignment,  disposition or
other alienation; or any option, equity, claim or right of or obligation to, any
other Person, of whatever kind and character.

         Material  Adverse  Effect  shall mean,  with respect to ATC or ATS, any
Event which is reasonably  likely,  in the reasonable  business  judgment of the
relevant  party,  to be  expected to (a)  materially  and  adversely  affect the
validity or  enforceability  of this Agreement or the likelihood of consummation
of the Merger, or (b) materially and adversely affect the business,  operations,
management,  properties or prospects,  or the condition,  financial or other, or
results of operation of ATC and its Subsidiaries taken as a whole or ATS and its
Subsidiaries taken as a whole, as applicable,  or (c) materially impair ATC's or
ATS' ability to fulfill its obligations  under the terms of this  Agreement,  or
(d)  materially  and adversely  affect the aggregate  rights and remedies of the
other party (other under this  Agreement.  Notwithstanding  the  foregoing,  and
anything in this Agreement to the contrary notwithstanding,  any Event generally
affecting the economy or the tower  communications  business shall not be deemed
to have a Material Adverse Effect.

         Material  Agreement  shall  mean,  with  respect  to  any  Person,  any
Contractual  Obligation  (other than  Contractual  Obligations  under  Contracts
governing the lease or rental of tower spaces to  third-party

                                       A-9


<PAGE>



customers) which (a) involves the purchase, sale or lease of goods or materials,
or  purchase  of  services,  whether  in or outside  of the  ordinary  course of
business (including,  without limitation,  acquisitions of communications towers
or tower businesses),  that individually  involves a purchase price in excess of
$2,000,000,  (b) involves a capitalized  lease  obligation or  Indebtedness  for
Money Borrowed in excess of $1,000,000,  (c) involves a written agency,  broker,
dealer,  license,  distributorship,  sales  representative  or  similar  written
agreement  pursuant to which such Person or its  Subsidiaries  made  payments in
excess of $1,000,000 during the preceding twelve-month period, (d) accounted for
more than 3% of the  revenues of the business of such Person in any of the three
fiscal  years or is likely to account  for more than 3% of the  revenues  of the
business of such  Person  during the  current  fiscal  year,  (e)  involves  the
management  by such  Person of more than ten (10)  communication  towers for any
other Person,  (f) is a partnership,  limited  liability  company or other joint
venture,  (g) grants any Person the  exclusive  right to  represent  ATS and its
Subsidiaries  of ATC and its  Subsidiaries,  as the case may be, with respect to
brokering tower transactions, or marketing tower space or administering tower or
(h) limits the freedom to compete in any line of business or to conduct business
in any geographic location.

         Merger  shall  have  the  meaning  given  to it in  the  first  Whereas
paragraph.

         Merger  Consideration  shall  have the  meaning  given to it in Section
3.1(b).

         Multiemployer  Plan shall mean a Plan which is a  "multiemployer  plan"
within the meaning of Section 3(37) or 4001(a)(3) of ERISA.

         Nasdaq shall have the meaning given to it in Section 3.1.

         Option  Securities  shall mean all rights,  options and  warrants,  and
calls or  commitments  evidencing  the right,  to  subscribe  for,  purchase  or
otherwise acquire shares of capital stock or Convertible Securities,  whether or
not the right to subscribe  for,  purchase or otherwise  acquire is  immediately
exercisable  or is  conditioned  upon the  passage of time,  the  occurrence  or
non-occurrence or the existence or non-existence of some other Event.

         Organic  Document  shall  mean,  with  respect  to a Person  which is a
corporation,  its charter,  its by-laws and all shareholder  agreements,  voting
trusts and similar arrangements applicable to any of its capital stock and, with
respect to a Person which is a  partnership,  its agreement and  certificate  of
partnership,  any  agreements  among  partners,  and any  management and similar
agreements  between the partnership  and any general  partners (or any Affiliate
thereof).

         Permitted  Liens shall mean (a) Liens for current taxes not yet due and
payable, (b) such imperfections of title, easements,  encumbrances and mortgages
or other Liens, if any, as, individually or in the aggregate,  do not materially
detract from the value, or materially interfere with the present use, of the ATC
Assets or the ATS Assets, as the case may be, or otherwise materially impair the
conduct of the ATC  Business  or the ATS  Business,  as the case may be, and (c)
such other Liens as are permitted by the  provisions of this  Agreement to be in
place on the Closing Date.

         Person shall mean any natural individual or any Entity.

         Plan shall mean,  with respect to any Person and at a particular  time,
any employee benefit plan which is covered by ERISA and in respect of which such
Person or an ERISA  Affiliate is (or, if such plan were 

                                      A-10


<PAGE>


terminated  at such time,  would under Section 4069 of ERISA be deemed to be) an
"employer"  as defined in Section 3(5) of ERISA,  but only to the extent that it
covers or relates to any officer, employee, individual or Entity involved in the
ownership  and  operation  of the  assets of such  Person or the  conduct of the
business of such Person.

         Preferred Stock Merger consideration shall have the meaning given to it
in Section 3.1(d).

         Private Authorizations shall mean all approvals, concessions, consents,
franchises,  licenses,  permits,  and other authorizations of all Persons (other
than Authorities)  including without limitation those with respect to Intangible
Assets.

         Regulations  shall mean the federal income tax regulations  promulgated
under  the Code,  as such  Regulations  may be  amended  from time to time.  All
references  herein to specific  sections of the Regulations shall be deemed also
to refer to any  corresponding  provisions  of succeeding  Regulations,  and all
references  to  temporary  Regulations  shall  be  deemed  also to  refer to any
corresponding provisions of final Regulations.

         Representatives shall have the meaning given to it in Section 6.1(a).

         Restricted  Information  shall have the meaning  given to it in Section
6.1.

         Restricted  Transaction  shall mean any (i) acquisition or agreement to
acquire (x) by merging or  consolidating  with,  or by  purchasing a substantial
portion of the assets of, or by any other manner,  any business or any Person or
other business organization or division thereof or (y) any assets (other than in
the ordinary  course of business which for purposes of this  definition does not
include the  acquisition  of  communications  sites and related assets and other
business  involved in the  communications  sites industry or the construction of
communications  towers and related assets), or (ii) any undertaking or agreement
to undertake the construction of one or more communications towers.

         Securities Act shall mean the Securities Act of 1933, and the rules and
regulations  thereunder,  all as from time to time in effect,  or any  successor
law,  rules or  regulations,  and any  reference to any  statutory or regulatory
provision  shall be deemed  to be a  reference  to any  successor  statutory  or
regulatory provision.

         Solvent  shall mean,  with respect to any Person on a particular  date,
that on such date (i) the fair value of the assets of such Person  (both at fair
valuation and at present fair saleable value) is, on the date of  determination,
greater than the total amount of  liabilities,  including,  without  limitation,
contingent and  unliquidated  liabilities,  of such Person,  (ii) such Person is
able to pay all liabilities of such Person as they mature, and (iii) such Person
does not have unreasonably small capital with which to carry on its business. In
computing the amount of contingent or unliquidated liabilities at any time, such
liabilities  will be computed at the amount which, in light of all the facts and
circumstances  existing at such time,  represents the amount that can reasonably
be  expected  to become an actual or matured  liability.  For  purposes  of this
definition,  "indebtedness"  shall mean any  liability  on a claim,  and "claim"
shall  mean (a)  right to  payment,  whether  or not such  right is  reduced  to
judgment,  liquidated,  unliquidated,  fixed,  contingent,  matured,  unmatured,
disputed,  undisputed, legal equitable, secured or unsecured, or (b) right to an
equitable  remedy  for  breach of  performance  if such  breach  gives rise to a
payment,  whether  or not such  right  to an  equitable  remedy  is  reduced  to
judgment, fixed, contingent,  matured, unmatured,  disputed, undisputed, secured
or unsecured.

         Subsidiary shall mean, with respect to a Person,  any Entity a majority
of the capital stock  ordinarily  entitled to vote for the election of directors
of which,  or if no such voting stock is  outstanding,  a majority of

                                      A-11


<PAGE>



the equity  interests  of which,  is owned  directly or  indirectly,  legally or
beneficially, by such Person or any other Person controlled by such Person.

         Surviving  Corporation  shall have the  meaning  given to it in Section
2.1.

         Tax (and "Taxable",  which shall mean subject to Tax), shall mean, with
respect to any Person,  (a) all taxes (domestic or foreign),  including  without
limitation any income (net, gross or other including  recapture of any tax items
such as  investment  tax  credits),  alternative  or add-on  minimum tax,  gross
income,  gross receipts,  gains,  sales, use, leasing,  lease, user, ad valorem,
transfer, recording, franchise, profits, property (real or personal, tangible or
intangible),  fuel,  license,  withholding on amounts paid to or by such Person,
payroll,  employment,  unemployment,  social security, excise, severance, stamp,
occupation, premium, environmental or windfall profit tax, custom, duty or other
tax, or other like  assessment or charge of any kind  whatsoever,  together with
any  interest,  levies,  assessments,  charges,  penalties,  addition  to tax or
additional  amount  imposed  by any Taxing  Authority,  (b) any joint or several
liability of such Person with any other Person for the payment of any amounts of
the type  described in (a) and (c) any  liability of such Person for the payment
of any  amounts  of the type  described  in (a) as a result  of any  express  or
implied obligation to indemnify any other Person.

         Tax Return or Returns shall mean all returns, consolidated or otherwise
(including without limitation  information  returns),  required to be filed with
any Authority with respect to Taxes.

         Taxing   Authority  shall  mean  any  Authority   responsible  for  the
imposition of any Tax.

         Termination  Date  shall  mean May 31,  1998 or such  other date as the
parties may, from time to time, mutually agree.

         Transactions shall mean the transactions contemplated by this Agreement
to be consummated on or prior to the Closing Date,  including without limitation
the  Merger  and the  execution,  delivery  and  performance  of the  Collateral
Documents.

         Tower  Distribution shall mean the pro rata distribution by ARS to each
ARS common stockholder of a umber of shares of ATS Common Stock such that, after
giving to such  distribution,  (i)  immediately  prior to the  Merger,  such ARS
common  stockholder  will  own the  same  percentage  of ATS as it  owned of ARS
determined as if all Convertible Securities of ARS had been so converted and all
Option  Securities  of ARS had ben  exercised,  (ii)  neither ARS nor any of its
Subsidiaries  owns any  capital  stock in ATS or its  Subsidiaries,  other  than
shares of ATS Common  Stock (a) required to satisfy ARS  Convertible  Securities
and ARS Option Securities in the manner contemplated by the CBS Merger Agreement
or (b)  owned  with  respect  to (x)  shares  of ARS  Common  Stock  as to which
appraisal  rights have been asserted as a consequence of the Tower  Distribution
or (y) ARS Option Securities which have been converted to ATS Option Securities,
and (iii) the Tower Distribution will have been made in all material respects in
accordance with Applicable Law including Federal securities laws.



                                      A-12



                                                                    EXHIBIT 2.2

                          AGREEMENT AND PLAN OF MERGER

                                  By and Among

                       AMERICAN TOWER SYSTEMS CORPORATION,

                          AMERICAN TOWER SYSTEMS, INC.

                               GEARON & CO., INC.

                                       and

                             J. MICHAEL GEARON, JR.

                                   Dated as of

                                NOVEMBER 21, 1997

















<PAGE>

<TABLE>
<CAPTION>

                                TABLE OF CONTENTS
                                                                                                               Page
<S>              <C>                                                                                            <C>

ARTICLE 1         DEFINED TERMS...................................................................................1

ARTICLE 2         THE MERGER......................................................................................2
                  2.1      The Merger.............................................................................2
                  2.2      Closing................................................................................2
                  2.3      Effective Time.........................................................................2
                  2.4      Effect of the Merger...................................................................2
                  2.5      Certificate of Incorporation...........................................................2
                  2.6      Bylaws.................................................................................2
                  2.7      Directors and Officers.................................................................2

ARTICLE 3         CONVERSION OF SHARES; EXCHANGE OF CERTIFICATES..................................................3
                  3.1      Conversion of Capital Stock............................................................3
                  3.2      Exchange of Certificates...............................................................4
                  3.3      Stock Transfer Books...................................................................4
                  3.4      Option Securities and Convertible Securities; Payment Rights...........................4

ARTICLE 4         REPRESENTATIONS AND WARRANTIES OF GEARON .......................................................4
                  4.1      Organization and Business; Power and Authority; Effect of Transaction..................4
                  4.2      Financial and Other Information.  .....................................................5
                  4.3      Material Statements and Omissions; Absence of Events...................................5
                  4.4      Title to Properties; Leases............................................................6
                  4.5      Compliance with Private Authorizations.................................................7
                  4.6      Compliance with Governmental Authorizations and Applicable Law.........................7
                  4.7      Intangible Assets......................................................................8
                  4.8      Related Transactions...................................................................9
                  4.9      Insurance..............................................................................9
                  4.10     Tax Matters.  .........................................................................9
                  4.11     Employee Retirement Income Security Act of 1974.......................................10
                  4.12     Absence of Sensitive Payments.........................................................10
                  4.13     Bank Accounts, Etc....................................................................10
                  4.14     Employment Arrangements...............................................................10
                  4.15     Material Agreements...................................................................11
                  4.16     Ordinary Course of Business...........................................................11
                  4.17     Material and Adverse Restrictions.....................................................12
                  4.18     Broker or Finder......................................................................12
                  4.19     Solvency..............................................................................12
                  4.20     Environmental Matters.................................................................12
                  4.21     Capital Stock.........................................................................14
                  4.22     Materiality...........................................................................14

ARTICLE 5         REPRESENTATIONS AND WARRANTIES OF ATS AND ATSI.................................................14
                  5.1      Organization and Business; Power and Authority; Effect of Transaction.................14
                  5.2      Financial and Other Information.  ....................................................15
                  5.3      Material Statements and Omissions; Absence of Events..................................15
                  5.5      Title to Properties; Leases...........................................................16
                  5.6      Compliance with Private Authorizations................................................16
                  5.7      Compliance with Governmental Authorizations and Applicable Law........................16

                                      

<PAGE>


                  5.8      Related Transactions..................................................................17
                  5.9      Tax Matters...........................................................................17
                  5.10     Ordinary Course of Business...........................................................17
                  5.11     Environmental Matters.................................................................18
                  5.12     Materiality...........................................................................19
                  5.13     Material and Adverse Restrictions.....................................................19
                  5.14     Broker or Finder......................................................................19
                  5.15     Solvency..............................................................................19
                  5.16     Capital Stock.........................................................................19
                  5.17     Employment Arrangements...............................................................20
                  5.18     Investment Representation.............................................................20
                  5.19     Covenant Regarding Transfer...........................................................20

ARTICLE 6         REPRESENTATIONS AND WARRANTIES OF THE GEARON STOCKHOLDER
                  RELATING TO THE SUBJECT STOCK..................................................................20
                  6.1      Enforceability........................................................................20
                  6.2      Title to Shares.......................................................................21
                  6.3      No Conflict; Required Filings and Consents............................................21

ARTICLE 7         COVENANTS......................................................................................21
                  7.1      Access to Information; Confidentiality.  .............................................21
                  7.2      Agreement to Cooperate.  .............................................................22
                  7.3      Public Announcements..................................................................23
                  7.4      Notification of Certain Matters.......................................................23
                  7.5      No Solicitation.......................................................................24
                  7.6      Conduct of Business by ATSI Pending the Merger........................................24
                  7.7      Conduct of Business by Gearon Pending the Merger......................................24
                  7.8      Preliminary Title Reports.............................................................26
                  7.9      Environmental Site Assessments........................................................26
                  7.10     Interim Financing for Gearon..........................................................27

ARTICLE 8         CLOSING CONDITIONS.............................................................................27
                  8.1      Conditions to Obligations of Each Party...............................................27
                  8.2      Conditions to Obligations of ATS and ATSI.............................................27
                  8.3      Conditions to Obligations of Gearon.  ................................................30

ARTICLE 9         TERMINATION, AMENDMENT AND WAIVER..............................................................31
                  9.1      Termination...........................................................................31
                  9.2      Effect of Termination.................................................................32

ARTICLE 10        INDEMNIFICATION................................................................................32
                  10.1     Survival..............................................................................32
                  10.2     Indemnification.......................................................................33
                  10.3     Limitation of Liability...............................................................33
                  10.4     Notice of Claims......................................................................34
                  10.5     Defense of Third Party Claims.........................................................34
                  10.6     Exclusive Remedy......................................................................34

ARTICLE 11        GENERAL PROVISIONS.............................................................................35

                                      -ii-

<PAGE>


                  11.1     Waivers; Amendments...................................................................35
                  11.2     Fees, Expenses and Other Payments.....................................................35
                  11.3     Notices...............................................................................35
                  11.4     Specific Performance; Other Rights and Remedies.......................................36
                  11.5     Severability..........................................................................36
                  11.6     Counterparts..........................................................................37
                  11.7     Section Headings......................................................................37
                  11.8     Governing Law.........................................................................37
                  11.9     Further Acts..........................................................................37
                  11.10    Entire Agreement......................................................................37
                  11.11    Assignment............................................................................38
                  11.12    Parties in Interest...................................................................38
                  11.14    Due Diligence.........................................................................38

</TABLE>

APPENDIX A:       Definitions

EXHIBITS:

         EXHIBIT A:        Gearon Notes (Section 7.10).
         EXHIBIT B:        Security Agreement (Section 7.10).
         EXHIBIT C:        ATS Noncompetition Agreement (Section 8.2(i)).
         EXHIBIT D:        Gearon Employment Agreement (Section 8.2(n)).
         EXHIBIT E:        Indemnity Escrow Agreement (Section 8.2(o)).
         EXHIBIT F:        Registration Rights Agreement (Section 8.2(p)).
         EXHIBIT G:        Investment Letter (Section 8.2(r)).


                                      -iii-

<PAGE>



                          AGREEMENT AND PLAN OF MERGER


         Agreement  and Plan of Merger,  dated as of November 21,  1997,  by and
among  American  Tower  Systems  Corporation,  a Delaware  corporation  ("ATS"),
American  Tower Systems,  Inc. a Delaware  corporation  ("ATSI"),  Gearon & Co.,
Inc., a Georgia corporation ("Gearon"),  and J. Michael Gearon, Jr. (the "Gearon
Stockholder").

                              W I T N E S S E T H:

         WHEREAS,  the  respective  Boards of Directors of ATS,  ATSI and Gearon
have  approved  the merger  (the  "Merger")  of Gearon with and into ATSI on the
terms and  conditions  set  forth in this  Agreement  and Plan of  Merger  (this
"Agreement") and have approved this Agreement; and

         WHEREAS,  the Board of  Directors  of ATS has approved and adopted this
Agreement as the sole  stockholder of ATSI,  and the sole voting  shareholder of
Gearon has approved and adopted this Agreement; and

         WHEREAS, this Agreement provides that Gearon shall be merged into ATSI,
and ATSI shall be the surviving corporation; and

         WHEREAS,  as a condition  of the  willingness  of ATS and ATSI to enter
into this Agreement,  and as an inducement  thereto,  the Gearon  Stockholder is
delivering  his  written  consent  approving  and  adopting  the Merger and this
Agreement;

         NOW,   THEREFORE,   in   consideration   of  the   premises   and   the
representations, warranties, covenants and agreements herein contained and other
valuable   consideration,   the   receipt  and   adequacy   whereof  are  hereby
acknowledged,  the  parties  hereto  hereby,  intending  to  be  legally  bound,
represent, warrant, covenant and agree as follows:


                                    ARTICLE 1

                                  DEFINED TERMS

         As used  herein,  unless  the  context  otherwise  requires,  the terms
defined in  Appendix A shall have the  respective  meanings  set forth  therein.
Terms defined in the singular  shall have a comparable  meaning when used in the
plural,  and vice  versa,  and the  reference  to any gender  shall be deemed to
include all genders.  Unless otherwise  defined or the context otherwise clearly
requires,  terms for which  meanings are provided in this  Agreement  shall have
such meanings when used in the Gearon Disclosure  Schedule,  and each Collateral
Document  executed  or required  to be  executed  pursuant  hereto or thereto or
otherwise delivered,  from time to time, pursuant hereto or thereto.  References
to "hereof," "herein" or similar terms are intended to refer to the Agreement as
a whole and not a particular section,  and references to "this Section" or "this
Article"  are  intended  to refer to the entire  section  or  article  and not a
particular subsection thereof. The term "either party" shall, unless the context
otherwise  requires,  refer to ATS and ATSI, on the one hand, and Gearon and the
Gearon Stockholder, on the other hand.



                                                     


<PAGE>



                                    ARTICLE 2

                                   THE MERGER

         2.1 The Merger.  Upon the terms and subject to the conditions set forth
in this Agreement,  and in accordance with the Delaware General  Corporation Law
(the "DCL") and the  Georgia  Business  Corporation  Code (the  "GBCC"),  at the
Effective  Time,  Gearon shall be merged with and into ATSI.  As a result of the
Merger,  the separate  corporate  existence of Gearon shall cease and ATSI shall
continue as the surviving  corporation in the Merger (sometimes  referred to, as
such, as the "Surviving Corporation"). ATS and Gearon acknowledge and agree that
it is the intention of the parties that the business of Gearon  conducted  prior
to the Effective Time continue to be operated and expanded  either as a distinct
operating division of ATSI or as a wholly owned subsidiary of ATSI.

         2.2 Closing.  Unless this Agreement shall have been terminated pursuant
to Section 9.1 and subject to the  satisfaction  or, to the extent  permitted by
Applicable  Law, waiver of the conditions set forth in Article 8, the closing of
the Merger (the  "Closing") will take place, at 10:00 a.m., on the Closing Date,
at the offices of  Sullivan & Worcester  LLP,  One Post Office  Square,  Boston,
Massachusetts  02109, on the date that is the second (2nd) day after the date on
which all of the  conditions  set forth in  Article 8 (other  than  those  which
require  delivery of  opinions  or  documents  at the  Closing)  shall have been
satisfied or waived,  unless another date, time or place is agreed to in writing
by the parties.  The date on which the Closing  occurs is herein  referred to as
the "Closing Date."

         2.3 Effective  Time.  Subject to the provisions of this  Agreement,  as
promptly as  practicable  after the Closing,  the parties hereto shall cause the
Merger to be  consummated  by filing a  Certificate  of Merger  and any  related
filings  required  under  the DCL with the  Secretary  of State of the  State of
Delaware and Articles of Merger and any related filings  required under the GBCC
with the  Secretary  of State of the State of Georgia.  The Merger  shall become
effective at such time as such documents are duly filed as aforesaid, or at such
later time as is specified in such documents (the "Effective Time").

         2.4 Effect of the Merger.  The Merger  shall have the effects  provided
for under the DCL and the GBCC.

         2.5 Certificate of  Incorporation.  The Certificate of Incorporation of
ATSI,  as in  effect  immediately  prior  to the  Effective  Time,  shall be the
Certificate  of  Incorporation  of the Surviving  Corporation  until  thereafter
changed or amended as provided therein or by Applicable Law.

         2.6 Bylaws. The bylaws of ATSI in effect at the Effective Time shall be
the  bylaws of the  Surviving  Corporation  until  amended  in  accordance  with
Applicable Law and the Organic Documents of ATSI.

         2.7 Directors and Officers.  From and after the Effective  Time,  until
successors  are duly elected or appointed and  qualified,  or upon their earlier
resignation  or  removal,  in  accordance  with  Applicable  Law and the Organic
Documents of ATSI,  and subject to  satisfaction  of the  condition set forth in
Sections  8.3(g) and 8.3(j),  (a) the  directors of ATSI at the  Effective  Time
shall be the  directors of the  Surviving  Corporation,  and (b) the officers of
ATSI at the Effective Time shall be the officers of the Surviving Corporation.



                                       -2-


<PAGE>



                                    ARTICLE 3

                 CONVERSION OF SHARES; EXCHANGE OF CERTIFICATES

         3.1  Conversion of Capital Stock.  At the Effective  Time, by virtue of
the Merger and  without  any action on the part of ATS,  ATSI or Gearon or their
respective stockholders:

                  (a) Each share of Common Stock,  par value $.01 per share,  of
         ATSI issued and  outstanding  immediately  prior to the Effective  Time
         shall remain outstanding.

                  (b) Each share of Common Stock,  no par value,  of Gearon (the
         "Gearon Common Stock") issued and outstanding  immediately prior to the
         Effective  Time  (other  than  shares  held in the  treasury of Gearon)
         shall,  by virtue of the Merger and  without  any action on the part of
         the holder thereof, be converted into the right to receive its pro-rata
         share of the following:

                           (i) with respect to Dan King  Brainard,  Jeff Ebihara
                  and  Doug   Wiest,   555,555,   16,666  and   33,333   shares,
                  respectively,  of Class A Common  Stock,  par  value  $.01 per
                  share, of ATS (the "ATS Class A Common Stock") (being a number
                  of shares of ATS Class A Common Stock with an agreed upon fair
                  market   value   of   $5,000,000,   $150,000   and   $300,000,
                  respectively,  based on an agreed  upon per share value of the
                  ATS Class A Common Stock of $9.00, which ATS represents is not
                  more than the price per share at which  shares  are to be sold
                  pursuant  to the ATS Private  Placement)  to be issued to each
                  such Gearon  stockholder in proportion to the number of shares
                  of Gearon Common Stock held by such  stockholder to the number
                  of shares of Gearon Common Stock held by all such stockholders
                  (the "Gearon Employees Consideration" which term shall include
                  any  adjustment  pursuant to the  provisions of this Section);
                  and

                           (ii) with respect to the Gearon  Stockholder  and the
                  Gearon Family Partnership, (A) 4,727,778 shares of ATS Class A
                  Common  Stock  (being a number of shares of ATS Class A Common
                  Stock with an agreed  upon fair  market  value of  $42,550,000
                  based on an  agreed  upon per  share  value of the ATS Class A
                  Common Stock of $9.00,  which ATS  represents is not more than
                  the price per share at which shares are to be sold pursuant to
                  the  ATS  Private   Placement)   (the  "Gearon   Common  Stock
                  Consideration"),   and  (B)  $32.0   million  in   immediately
                  available funds (the "Cash  Consideration"  and  collectively,
                  with  the  Gearon  Common  Stock  Consideration,  the  "Merger
                  Consideration"   which  term  shall  include  any   adjustment
                  pursuant to the provisions of this Section).

         Notwithstanding  the  foregoing,  the Cash  Consideration  shall be (i)
         increased by an amount  equal to the Net Working  Capital of Gearon (if
         positive)  on and as of the  Closing  Date,  and (ii)  decreased  by an
         amount equal to the Net Working  Capital of Gearon (if negative) on and
         as of the Closing Date. The term "Exchange Merger  Consideration" shall
         mean an  amount  equal to the  Gearon  Employees  Consideration  or the
         Merger  Consideration,  as the case may be,  divided  by the  aggregate
         number of shares of Gearon  Common Stock (the "Gearon  Shares")  issued
         and  outstanding  at the  Effective  Time  and  held of  record  at the
         Effective  Time by the Persons (x) named in paragraph  (i), in the case
         of the Gearon Employees Consideration, and (y) named in paragraph (ii),
         in the  case of the  Gearon  Common  Stock  Consideration  and the Cash
         Consideration.


                                       -3-

<PAGE>

         At the Effective Time, all Gearon Shares shall no longer be outstanding
and shall  automatically  be canceled and retired and shall cease to exist,  and
certificates   previously   evidencing   any  such  Gearon   Shares   (each,   a
"Certificate")  shall  thereafter  represent  the  right  to  receive,  upon the
surrender of such  Certificate in accordance with the provisions of Section 3.2,
the Exchange  Merger  Consideration  multiplied  by the number of Gearon  Shares
represented by such Certificate, and a holder of more than one Certificate shall
have the right to receive the Exchange  Merger  Consideration  multiplied by the
number of Gearon Shares represented by all such Certificates. In lieu of issuing
fractional  shares,  ATS shall convert the holder's right to receive ATS Class A
Common Stock  pursuant to the provisions of this Section into a right to receive
the highest whole number of shares of ATS Class A Common Stock  constituting the
Exchange Merger  Consideration plus cash equal to the fraction of a share of ATS
Class A Common Stock to which the holder would otherwise be entitled  multiplied
by $[i],  and the Exchange  Merger  Consideration  to which a holder is entitled
shall be deemed to be such  number  of shares of ATS Class A Common  Stock,  the
Cash  Consideration and such cash. The holders of such  Certificates  previously
evidencing  Gearon Shares  outstanding  immediately  prior to the Effective Time
shall cease to have any rights with  respect to such  Gearon  Shares,  except as
otherwise provided herein or by Applicable Law.

         3.2 Exchange of  Certificates.  At and after the Effective  Time,  each
stockholder  of Gearon,  upon  surrender of each of his  Certificates,  shall be
issued a  certificate  of ATS  Class A Common  Stock and cash  representing  the
Exchange Merger  Consideration  with respect to the Gearon Shares represented by
such  Certificate in accordance with the provisions of Section 3.1, plus cash in
amount sufficient to make payment for fractional shares,  subject,  however,  to
the provisions of the Indemnity Escrow Agreement.

         3.3 Stock  Transfer  Books.  At the Effective  Time, the stock transfer
books of Gearon  shall be  closed,  and there  shall be no further  transfer  of
shares  of  Gearon  Common  Stock  thereafter  on the  records  of  Gearon.  Any
Certificates  presented  after the Effective Time for transfer shall be canceled
and  exchanged  for the amount to which the Gearon  Shares  represented  thereby
shall be entitled pursuant to Sections 3.1 and 3.2.

         3.4 Option  Securities and Convertible  Securities;  Payment Rights. At
the  Effective  Time,  each  outstanding  Option  Security and each  Convertible
Security of Gearon,  if any,  whether or not then exercisable for or convertible
into Gearon Shares or other Gearon securities,  outstanding immediately prior to
the Effective Time,  shall be canceled and retired and shall cease to exist, and
the holder thereof shall not be entitled to receive any consideration therefor.


                                    ARTICLE 4

                    REPRESENTATIONS AND WARRANTIES OF GEARON

         Gearon  and the  Gearon  Stockholder,  jointly  and  severally,  hereby
represent and warrant to ATS and ATSI as follows:

         4.1  Organization  and  Business;   Power  and  Authority;   Effect  of
Transaction.

         (a) Gearon is a corporation  duly  organized,  validly  existing and in
good  standing  under  the laws of its  jurisdiction  of  organization,  has all
requisite  power and authority  (corporate and other) to own or hold under lease
its properties and to conduct its business as now conducted.


                                       -4-


<PAGE>

         (b) Gearon has all requisite power and authority  (corporate and other)
and has in full force and effect all  Governmental  Authorizations  and  Private
Authorizations necessary to enable it to execute and deliver, and to perform its
obligations  under,  this  Agreement and each  Collateral  Document  executed or
required to be executed by it pursuant  hereto or thereto or to  consummate  the
Transactions;  and the execution, delivery and performance of this Agreement and
each  Collateral  Document  executed  or  required to be executed by it pursuant
hereto or thereto have been duly authorized by all requisite  corporate or other
action on the part of Gearon,  including  without  limitation  by the  requisite
approval of the  stockholders  of Gearon.  This Agreement has been duly executed
and delivered by Gearon and constitutes,  and each Collateral  Document executed
or required to be executed by it pursuant hereto or thereto or to consummate the
Transactions when executed and delivered by Gearon will constitute, legal, valid
and  binding  obligations  of  Gearon,  enforceable  in  accordance  with  their
respective terms,  except as such  enforceability  may be subject to bankruptcy,
moratorium,  insolvency,   reorganization,   arrangement,  voidable  preference,
fraudulent conveyance and other similar laws relating to or affecting the rights
of  creditors  and  except as the same may be  subject  to the effect of general
principles of equity.

         (c)  Except as set forth in  Section  4.1(c) of the  Gearon  Disclosure
Schedule,  neither the execution and delivery by Gearon of this Agreement or any
Collateral Document executed or required to be executed by it pursuant hereto or
thereto,  nor the  consummation  of the  Transactions,  nor compliance  with the
terms, conditions and provisions hereof or thereof by Gearon:

                  (i) will conflict with, or result in a breach or violation of,
         or constitute a default  under,  any Organic  Document of Gearon or any
         Applicable  Law,  or will  conflict  with,  or  result  in a breach  or
         violation of, or constitute a default under, or permit the acceleration
         of any obligation or liability in, or but for any requirement of giving
         of notice or passage of time or both would  constitute  such a conflict
         with,  breach or  violation  of, or default  under,  or permit any such
         acceleration in, any Contractual Obligation of Gearon; or

                  (ii) will  require  Gearon to make or obtain any  Governmental
         Authorization,  Governmental Filing or Private Authorization  including
         without   limitation   under  the  FCA,   except  as  required  by  the
         Hart-Scott-Rodino Act.

         (d)  Except as set forth in  Section  4.1(d) of the  Gearon  Disclosure
Schedule, Gearon does not have any Subsidiaries.

         4.2 Financial and Other Information. Gearon has heretofore furnished to
ATS copies of the  financial  statements  of Gearon listed in Section 4.2 of the
Gearon  Disclosure  Schedule  (the "Gearon  Financial  Statements").  The Gearon
Financial  Statements,  including  in each  case the  notes  thereto,  have been
prepared in accordance  with GAAP applied on a consistent  basis  throughout the
periods  covered  thereby,  except as otherwise noted therein or as set forth in
Section 4.2 of the Gearon Disclosure  Schedule,  are true, accurate and complete
in all material respects, do not contain any untrue statement of a material fact
or omit to state a  material  fact  required  by GAAP to be  stated  therein  or
necessary in order to make the  statements  contained  therein,  in light of the
circumstances under which they were made, not misleading, and fairly present the
financial  condition and the results of operations  and cash flow of Gearon,  on
the bases  therein  stated,  as of the  respective  dates  thereof,  and for the
respective periods covered thereby subject,  in the case of unaudited  financial
statements, to normal nonmaterial year-end audit adjustments and accruals.

         4.3 Material Statements and Omissions;  Absence of Events.  Neither any
representation  or warranty  made by Gearon  contained in this  Agreement or any
certificate, document or other instrument

                                       -5-


<PAGE>


furnished or to be furnished by Gearon pursuant to the provisions hereof nor the
Gearon  Disclosure  Schedule  contains or will contain any untrue statement of a
material  fact or omits or will omit to state any material fact required to make
any statement  contained herein or therein,  in light of the circumstances under
which  they  were  made,  not  misleading.  Since  the date of the  most  recent
financial  statements  constituting a part of the Gearon  Financial  Statements,
except  to the  extent  specifically  described  in  Section  4.3 of the  Gearon
Disclosure Schedule,  there has been no material adverse change in Gearon. There
is no Event known to Gearon which materially  adversely  affects,  or (so far as
Gearon can now  reasonably  foresee) is likely to materially  adversely  affect,
Gearon, except to the extent specifically described in Section 4.3 of the Gearon
Disclosure Schedule.  Gearon is not aware of any impending or contemplated Event
that would cause any of the  representations  and warranties  made by it in this
Article  not to be true,  correct  and  complete on the date of such Event as if
made on that date.

         4.4      Title to Properties; Leases.

         (a) Section 4.4(a) of the Gearon  Disclosure  Schedule contains a true,
accurate and complete  description  of all real property owned by Gearon that is
part of the property and assets of Gearon (the "Gearon Assets").  Gearon has, to
Gearon's  knowledge,  good  indefeasible,  marketable and insurable title to all
real property  (other than leasehold real  property) and good  indefeasible  and
marketable  title to all other assets (other than real  property),  tangible and
intangible,  constituting a part of the Gearon Assets; all of such real property
and other assets are so owned, in each case, free and clear of all Liens, except
(i) Permitted  Liens,  and (ii) Liens set forth on Section  4.4(a) of the Gearon
Disclosure Schedule.  Except for financing statements  evidencing Liens referred
to in the preceding sentence (a true, accurate and complete list and description
of which is set forth in Section 4.4(a) of the Gearon Disclosure  Schedule),  no
financing statements under the Uniform Commercial Code and no other filing which
names  Gearon as debtor or which  covers or  purports to cover any of the Gearon
Assets is on file in any state or other jurisdiction,  and Gearon has not signed
or  agreed to sign any such  financing  statement  or  filing  or any  agreement
authorizing any secured party thereunder to file any such financing statement or
filing. Except as disclosed in Section 4.4(a) of the Gearon Disclosure Schedule,
all improvements on the real property owned or leased by Gearon are, to Gearon's
knowledge,  in compliance  with applicable  zoning,  wetlands and land use laws,
ordinances  and  regulations  and  applicable   title   covenants,   conditions,
restrictions  and  reservations  in  all  respects   necessary  to  conduct  the
operations as presently  conducted,  except for any instances of  non-compliance
which do not and will not in the aggregate have a material adverse effect on the
owner or lessee, as the case may be, of such real property.  Except as disclosed
in Section  4.4(a) of the Gearon  Disclosure  Statement,  all such  improvements
comply  in  all  material  aspects  with  all  Applicable   Laws,   Governmental
Authorizations and Private Authorizations. Except as disclosed in Section 4.4(a)
of the Gearon  Disclosure  Statement,  all of the  transmitting  towers,  ground
radials, guy anchors,  transmitting buildings and related improvements,  if any,
located on the real property  owned or leased by Gearon are located  entirely on
such real property. There is no pending or, to Gearon's knowledge, threatened or
contemplated  action to take by eminent  domain or otherwise to condemn any part
of any real  property  owned by  Gearon  or,  to  Gearon's  knowledge,  any real
property  leased by Gearon.  Except as set forth in Section 4.4(a) of the Gearon
Disclosure  Schedule,  such real  property  (other than land),  fixtures,  fixed
assets and other material items of personal property, including equipment, have,
in Gearon's reasonable business judgment, been maintained in a manner consistent
with generally  accepted  standards of sound engineering  practice and currently
permit the Gearon Business to be operated in all material respects in accordance
with  the  terms  and   conditions   of  all   Applicable   Laws,   Governmental
Authorizations and Private Authorizations.

         (b) Section 4.4(b) of the Gearon  Disclosure  Schedule contains a true,
accurate and complete  description  of all Leases under which any real  property
used in the  business of Gearon (the  "Gearon  Business")  is leased.  Except as
otherwise set forth in Section 4.4(b) of the Gearon  Disclosure  Schedule,  each

                                       -6-


<PAGE>

Lease or other  occupancy  or other  agreement  under which Gearon holds real or
personal  property  constituting  a part of the  Gearon  Assets  has  been  duly
authorized, executed and delivered by Gearon and, to Gearon's knowledge, each of
the other  parties  thereto,  and is a legal,  valid and binding  obligation  of
Gearon,  and,  to  Gearon's  knowledge,  each  of  the  other  parties  thereto,
enforceable in accordance with its terms,  except as such  enforceability may be
limited by  bankruptcy,  moratorium,  insolvency  and similar laws affecting the
rights and remedies of creditors  and  obligations  of debtors  generally and by
general  principles  of equity.  Gearon has a valid  leasehold  interest  in and
enjoys peaceful and undisturbed possession under all Leases pursuant to which it
holds any such real property or tangible personal  property.  All of such Leases
are valid and  subsisting  and in full force and effect;  neither Gearon nor, to
Gearon's  knowledge,  any other party  thereto,  is in  material  default in the
performance,  observance or fulfillment of any obligation, covenant or condition
contained in any such Lease. None of the fixed assets or equipment  comprising a
part of the Gearon  Assets is subject to contracts of sale,  and none is held by
Gearon as lessee or as  conditional  sales vendee under any Lease or conditional
sales contract and none is subject to any title retention  agreement,  except as
set forth in Section 4.4(b) of the Gearon Disclosure Schedule.

         (c) Section 4.4(c) of the Gearon  Disclosure  Schedule contains a true,
accurate and complete  description of all material items of Personal Property of
Gearon.  Gearon owns and has good and  marketable  title to all of its  Personal
Property,  in each case, free and clear of all Liens, except (i) Permitted Liens
and (ii) Liens set forth on Section  4.4(c) of the  Gearon  Disclosure  Schedule
(which Liens shall be released prior to Closing). Except as set forth in Section
4.4(c) of the Gearon Disclosure  Schedule,  and except for any defects or damage
that would not, in the aggregate,  have a material adverse effect on Gearon, all
of the Personal  Property of Gearon is in a state of good repair and maintenance
and is in good  operating  condition,  normal wear and tear  excepted,  has been
maintained in a manner  consistent  with  generally  accepted  standards of good
engineering practice and currently permits the Gearon Business to be operated in
accordance with the terms and conditions of all Applicable Laws.

         4.5 Compliance with Private  Authorizations.  Section 4.5 of the Gearon
Disclosure   Schedule  sets  forth  a  true,  accurate  and  complete  list  and
description of each Private  Authorization which individually is material to the
Gearon  Assets  or  the  Gearon  Business.   Gearon  has  obtained  all  Private
Authorizations  which are necessary for the ownership or operation of the Gearon
Assets  or the  conduct  of the  Gearon  Business  which,  if not  obtained  and
maintained, could, individually or in the aggregate, materially adversely affect
Gearon.  All of such Private  Authorizations  are valid and in good standing and
are in full force and  effect.  Gearon is not in breach or  violation  of, or in
default in the  performance,  observance  or  fulfillment  of, any such  Private
Authorization,  and no Event exists or has occurred,  which constitutes,  or but
for any  requirement  of  giving  of notice  or  passage  of time or both  would
constitute,  such a  breach,  violation  or  default,  under  any  such  Private
Authorization,  except for such  defaults,  breaches or violations as do not and
will not have in the aggregate any material  adverse  effect on Gearon.  No such
Private  Authorization is the subject of any pending or, to Gearon's  knowledge,
threatened attack, revocation or termination.

         4.6 Compliance with Governmental Authorizations and Applicable Law.

         (a) Section 4.6(a) of the Gearon  Disclosure  Schedule contains a true,
complete and accurate  description of each Governmental  Authorization  required
under  Applicable  Law (i) to own and operate the Gearon  Assets and conduct the
Gearon Business,  as currently conducted or proposed to be conducted on or prior
to the Closing  Date,  all of which are in full force and effect or (ii) that is
necessary to permit Gearon to execute and deliver this  Agreement and to perform
its obligations hereunder.  Gearon has obtained all Governmental  Authorizations
which are  necessary  for the ownership or operation of the Gearon Assets or the
conduct of the Gearon  Business as now conducted and which,  if not obtained and
maintained,  would,  

                                       -7-


<PAGE>

individually  or in the aggregate,  have any material  adverse effect on Gearon.
None of the Governmental  Authorizations  listed in Section 4.6(a) of the Gearon
Disclosure Schedule is subject to any restriction or condition which would limit
in any material  respect the ownership or operations of the Gearon Assets or the
conduct of the Gearon Business as currently  conducted,  except for restrictions
and conditions generally applicable to Governmental Authorizations of such type.
The  Governmental   Authorizations  listed  in  Section  4.6(a)  of  the  Gearon
Disclosure Schedule are valid and in good standing, are in full force and effect
and are not impaired in any material respect by any act or omission of Gearon or
its officers, directors,  employees or agents, and the ownership or operation of
the Gearon Assets or the conduct of the Gearon Business are in accordance in all
material  respects with the Governmental  Authorizations.  All material reports,
forms and statements  required to be filed by Gearon with all  Authorities  with
respect  to the  Gearon  Business  have been  filed and are true,  complete  and
accurate in all material  respects.  No such  Governmental  Authorization is the
subject of any  pending  or, to  Gearon's  knowledge,  threatened  challenge  or
proceeding to revoke or terminate any such  Governmental  Authorization.  Gearon
has no reason to believe that any such Governmental  Authorization  would not be
renewed in the name of Gearon by the granting Authority in the ordinary course.

         (b) Except as otherwise specifically described in Section 4.6(b) of the
Gearon Disclosure  Schedule,  neither Gearon nor any director or officer thereof
(in  connection  with the  ownership or  operation  of the Gearon  Assets or the
conduct of the Gearon Business) is in or is charged by any Authority with or, to
Gearon's  knowledge,  at any time since  January 1, 1995 has been in or has been
charged by any Authority with, or, to Gearon's knowledge, is threatened or under
investigation  by any  Authority  with respect to,  breach or  violation  of, or
default in the  performance,  observance  or  fulfillment  of, any  Governmental
Authorization  or any  Applicable Law relating to the ownership and operation of
the Gearon  Assets or the conduct of the Gearon  Business.  In  particular,  but
without  limiting the  generality of the foregoing,  there are no  applications,
Claims or Legal Actions pending or, to Gearon's knowledge,  threatened before or
by any Authority (x) relating to the ownership or operation of the Gearon Assets
or the conduct of the Gearon Business  which,  individually or in the aggregate,
are  reasonably  likely  to  result  in the  revocation  or  termination  of any
Governmental Authorization or the imposition of any restriction of such a nature
as would adversely affect the ownership or operation of the Gearon Assets or the
conduct of the Gearon Business;  (y) involving charges of illegal discrimination
by  Gearon  under  any  federal  or  state  employment  Laws,  or (z)  involving
Environmental Laws or zoning laws, except as otherwise specifically described in
Section 4.6(b) of the Gearon  Disclosure  Schedule  except,  in each case,  such
applications,  Claims or Legal Actions as do not and will not have, individually
or in the aggregate, any material adverse effect on Gearon.

         (c) Except as otherwise specifically described in Section 4.6(c) of the
Gearon Disclosure Schedule, no Event exists or has occurred,  which, to Gearon's
knowledge,  constitutes,  or but for any  requirement  of  giving  of  notice or
passage of time or both would constitute,  such a breach,  violation or default,
under (i) any Governmental  Authorization or any Applicable Law, except for such
breaches, violations or defaults as do not and will not have, individually or in
the  aggregate,  any  material  adverse  effect on  Gearon or (ii) any  material
requirement of any insurance carrier,  applicable to the ownership or operations
of the Gearon  Assets or the  conduct of the  Gearon  Business,  except for such
breaches, violations or defaults as do not and will not have, individually or in
the aggregate, any material adverse effect on Gearon.

         (d) With respect to matters, if any, of a nature referred to in Section
4.6(a), 4.6(b) or 4.6(c) of the Gearon Disclosure Schedule,  except as otherwise
specifically  described in Section 4.6(d) of the Gearon Disclosure Schedule, all
such  information and matters set forth in the Gearon  Disclosure  Schedule,  if
adversely determined against Gearon, will not, individually or in the aggregate,
have a materially adversely effect on Gearon.



                                       -8-


<PAGE>

         4.7 Intangible  Assets.  Section 4.7 of the Gearon Disclosure  Schedule
sets forth a true,  accurate and complete  description of all Intangible  Assets
(other than Governmental  Authorizations and Private Authorizations) relating to
the  ownership  and  operation of the Gearon Assets or the conduct of the Gearon
Business  held or used by Gearon,  including  without  limitation  the nature of
Gearon's  interest  in each and the  extent  to which  the same  have  been duly
registered in the offices as indicated  therein.  Except as set forth in Section
4.7 of the Gearon Disclosure Schedule, no Intangible Assets (except Governmental
Authorizations,  Private Authorizations, and the Intangible Assets so set forth)
are required for the  ownership or operation of the Gearon Assets or the conduct
of the Gearon Business as currently owned, operated and conducted or proposed to
be owned,  operated and conducted on or prior to the Closing  Date.  Gearon does
not, to its knowledge, wrongfully infringe upon or unlawfully use any Intangible
Assets  owned or claimed by another,  and Gearon has not  received any notice of
any claim or infringement relating to any such Intangible Asset.

         4.8  Related  Transactions.  Gearon  is not a party or  subject  to any
Contractual  Obligation  relating to the  ownership  or  operation of the Gearon
Assets or the  conduct  of the  Gearon  Business  between  Gearon and any of its
officers, directors, stockholders, employees or, to the knowledge of Gearon, any
Affiliate  of  any  thereof,   including  without   limitation  any  Contractual
Obligation  providing  for the  furnishing  of services to or by,  providing for
rental of property,  real,  personal or mixed,  to or from, or providing for the
lending or borrowing of money to or from or otherwise  requiring  payments to or
from,  any  such  Person,  other  than (a)  Employment  Arrangements  listed  or
described in Section 4.14 of the Gearon  Disclosure  Schedule,  (b)  Contractual
Obligations  between  Gearon and any of its directors,  stockholders,  officers,
employees  or  Affiliates  of  Gearon  or any of the  foregoing,  which  will be
terminated,  at no cost or expense to Gearon,  prior to the  Closing,  or (c) as
specifically set forth in Section 4.8 of the Gearon Disclosure Schedule.

         4.9 Insurance.  Gearon maintains, with respect to the Gearon Assets and
the Gearon  Business,  policies  of fire and  extended  coverage  and  casualty,
liability  and other forms of  insurance  in such amounts and against such risks
and losses as are set forth in Section 4.9 of the Gearon Disclosure Schedule.

         4.10 Tax Matters.

         (a) Gearon has in  accordance  with all  Applicable  Laws filed all Tax
Returns which are required to be filed, and has paid, or made adequate provision
for the payment of, all Taxes which have or may become due and payable  pursuant
to said Tax Returns and all other governmental  charges and assessments received
to date other than those Taxes being  contested in good faith for which adequate
provision has been made on the most recent  balance sheet forming part of Gearon
Financial  Statements.  The Tax  Returns  of Gearon  have been  prepared  in all
material respects in accordance with all Applicable Laws and generally  accepted
principles  applicable to taxation  consistently applied. All Taxes which Gearon
is  required  by law to  withhold  and  collect  have  been  duly  withheld  and
collected,  and  have  been  paid  over,  in a  timely  manner,  to  the  proper
Authorities to the extent due and payable. Gearon has not executed any waiver to
extend,  or  otherwise  taken or failed to take any  action  that would have the
effect of extending, the applicable statute of limitations in respect of any Tax
liabilities  of Gearon  for the fiscal  years  prior to and  including  the most
recent fiscal year.  Adequate provision has been made on the most recent balance
sheet forming part of Gearon Financial  Statements for all Taxes accrued through
the date of such balance sheet of any kind,  including interest and penalties in
respect thereof, whether disputed or not, and whether past, current or deferred,
accrued or unaccrued,  fixed,  contingent,  absolute or other, and there are, to
Gearon's  knowledge,  no past  transactions  or matters  which  could  result in
additional  Taxes of a material  nature to Gearon for which an adequate  reserve
has not  been  provided  on such  balance  sheet.  Gearon  is not a  "consenting
corporation" within the meaning of Section 341(f) of the Code. Gearon has at all
times been taxable as a Subchapter S corporation  under the 

                                      -9-
<PAGE>

Code,  and has never been a member of any  consolidated  group for Tax purposes,
except as  otherwise  set forth in  Section  4.10(a)  of the  Gearon  Disclosure
Schedule.

         (b) The  information  shown on the federal income Tax Returns of Gearon
for each of the most  recent two tax years  (true and  complete  copies of which
have, to the extent  requested by ATS, been furnished by Gearon to ATS) is true,
accurate  and  complete  in all  material  respects  and fairly  and  accurately
reflects the  information  purported  to be shown.  Federal and state income Tax
Returns  of  Gearon  have  not been  exam  ined by the IRS or  applicable  state
Authority, and Gearon has not been notified of any proposed examination,  except
as shown in Section 4.10(b) of the Gearon Disclosure Schedule.

         (c) Gearon is not a party to any tax sharing agreement or arrangement.

         4.11  Employee  Retirement  Income  Security  Act of  1974.  Except  as
described in Section 4.11 of the Gearon Disclosure Schedule:

         (a) Gearon  (which for purposes of this Section shall include any ERISA
Affiliate) is not making any  contribution to or sponsoring,  and has not at any
time since its organization  made any contribution to or sponsored,  any Plan or
Benefit Arrangement which is subject to ERISA.

         (b) Gearon is not and never has been a party to any Multiemployer  Plan
or made contributions to any such Plan.

         (c) Gearon does not maintain any Plan that provides benefits  described
in Section 3(1) of ERISA,  except as the  provisions of COBRA may apply,  to any
former employees or retirees of Gearon.

         (d) The execution, delivery and performance by Gearon of this Agreement
and the Collateral Documents executed or required to be executed pursuant hereto
and thereto will not involve any  prohibited  transaction  within the meaning of
ERISA or Section 4975 of the Code.

         4.12 Absence of  Sensitive  Payments.  Neither  Gearon nor, to Gearon's
knowledge,  any  of  its  officers,   directors,   employees,  agents  or  other
representatives,  has with respect to the Gearon  Assets or the Gearon  Business
(a) made any  contributions,  payments or gifts to or for the private use of any
governmental official, employee or agent where either the payment or the purpose
of such  contribution,  payment or gift is illegal  under the laws of the United
States or the  jurisdiction  in which made or (b)  established or maintained any
unrecorded fund or asset for any illegal purpose or made any false or artificial
entries on its books.

         4.13 Bank Accounts, Etc. Section 4.13 of the Gearon Disclosure Schedule
contains a true,  accurate and complete list as of the date hereof of all banks,
trust  companies,  savings and loan  associations  and brokerage  firms in which
Gearon  has an  account  or a safe  deposit  box and the  names  of all  Persons
authorized to draw thereon, to have access thereto, or to authorize transactions
therein,  the names of all Persons,  if any, holding valid and subsisting powers
of attorney from Gearon and a summary statement as to the terms thereof.  Gearon
agrees that prior to the Closing  Date it will not make or permit to be made any
change  affecting  any  bank,  trust  company,  savings  and  loan  association,
brokerage firm or safe deposit box or in the names of the Persons  authorized to
draw thereon, to have access thereto or to authorize  transactions therein or in
such powers of attorney,  or open any additional  accounts or boxes or grant any
additional  powers of  attorney,  without  in each case first  notifying  ATS in
writing.

                                      -10-
<PAGE>

         4.14  Employment  Arrangements.  Section 4.14 of the Gearon  Disclosure
Schedule  contains a true,  accurate and complete  list of all Gearon  employees
(the  "Gearon  Employees"),  together  with  each such  employee's  title or the
capacity in which he or she is employed and each such  employee's  compensation.
Gearon has no obligation or liability, contingent or other, under any Employment
Arrangement with any Gearon  Employee,  other than (i) those listed or described
in Section 4.14 of the Gearon  Disclosure  Schedule,  (ii) those incurred in the
ordinary and usual course of business,  or (iii) such obligations or liabilities
as do not and will not have, in the  aggregate,  any material  adverse effect on
Gearon.  Except as described in Section 4.14 of the Gearon Disclosure  Schedule,
(a) none of the  Gearon  Employees  is now,  or since  January 1, 1995 has been,
represented  by  any  labor  union  or  other  employee  collective   bargaining
organization,  and  Gearon is not,  and never has been,  a party to any labor or
other  collective  bargaining  agreement  with  respect  to any  of  the  Gearon
Employees,  (b) there are no pending grievances,  disputes or controversies with
any union or any other employee or collective  bargaining  organization  of such
employees,  or threats of strikes,  work  stoppages  or slowdowns or any pending
demands for collective  bargaining by any such union or other organization,  (c)
neither  Gearon nor any of such  employees is now, or has since  January 1, 1995
been, subject to or involved in or, to Gearon's knowledge,  threatened with, any
union  elections,  petitions  therefor  or other  organizational  or  recruiting
activities,  in each case with respect to the Gearon Employees,  and (d) none of
the  Gearon  Employees  has  notified  Gearon  that he or she does not intend to
continue  employment  with Gearon  until the Closing or with ATS  following  the
Closing.  Gearon has performed in all material respects all obligations required
to be performed under all Employment  Arrangements and is not in material breach
or  violation  of or in  material  default  or  arrears  under any of the terms,
provisions or conditions thereof.

         4.15  Material  Agreements.  Listed  on  Section  4.15  of  the  Gearon
Disclosure  Schedule are all Material  Agreements  relating to the  ownership or
operation of the Gearon Assets or the conduct of the Gearon Business or to which
Gearon is a party or to which it is bound or which any of the  Gearon  Assets is
subject.  True, accurate and complete copies of each of such Material Agreements
have been made  available  by Gearon to ATS and  Gearon  has  provided  ATS with
photocopies of all such Material Agreements  requested by ATS (or true, accurate
and  complete  descriptions  thereof  have been set forth in Section 4.15 of the
Gearon Disclosure  Schedule,  with respect to Material  Agreements  comprised of
site  leases  and site  licenses  granted  by Gearon to third  parties  and with
respect to Material  Agreements that are oral). All of such Material  Agreements
are valid,  binding  and  legally  enforceable  obligations  of Gearon  and,  to
Gearon's knowledge, all other parties thereto, except as such enforceability may
be limited by bankruptcy,  moratorium, insolvency and similar laws affecting the
rights and remedies of creditors  and  obligations  of debtors  generally and by
general principles of equity.  Gearon has duly complied with all of the material
terms  and  conditions  of each  such  Material  Agreement  and has not  done or
performed,  or failed  to do or  perform  (and  there is no  pending  or, to the
knowledge of Gearon,  Claim  threatened  in writing with which Gearon has not so
complied,  done and  performed  or failed to do and perform) any act which would
invalidate or provide  grounds for the other party thereto to terminate (with or
without notice,  passage of time or both) such Material  Agreement or impair the
rights or benefits,  or increase the costs, of Gearon under any of such Material
Agreements in any material respect.

         4.16  Ordinary  Course of  Business.  Gearon,  from the end of its most
recent  fiscal  quarter to the date  hereof,  except (i) as may be  described on
Section  4.16 of the Gearon  Disclosure  Schedule,  (ii) as may be  required  or
expressly  contemplated  by the  terms  of this  Agreement,  or  (iii) as may be
described in the Gearon Financial Statements,  including the notes thereto, with
respect to the Gearon Assets and the Gearon Business:

                  (a) has operated its business in all material  respects in the
         normal,  usual and customary  manner in the ordinary and regular course
         of business, consistent with prior practice;

                                      -11-
<PAGE>

                  (b) except in each case in the  ordinary  course of  business,
         consistent with prior practice it being understood that the acquisition
         of communications sites and assets involved in the communications sites
         industry is part of the ordinary course of business of Gearon:

                           (i) has not  incurred  any  obligation  or  liability
                  (fixed,  contingent or other)  individually  having a value in
                  excess of $50,000;

                           (ii)  has  not  sold  or  otherwise  disposed  of  or
                  contracted  to  sell  or  otherwise  dispose  of  any  of  its
                  properties or assets having a value in excess of $50,000;

                           (iii) has not entered into any individual  commitment
                  having a value in excess of $50,000; and

                           (iv) has not canceled any debts or claims;

                  (c) has not created or permitted to be created any Lien on any
         of its property, except for Permitted Liens;

                  (d) has not made or  committed  to make any  additions  to its
         property or any purchases of equipment,  except in the ordinary  course
         of business consistent with past practice or for normal maintenance and
         replacements;

                  (e) has not  increased the  compensation  payable or to become
         payable to any of the Gearon Employees other than nonmaterial increases
         in the ordinary course of business,  or otherwise  materially  altered,
         modified or changed the terms of their employment;

                  (f) has not suffered any material damage,  destruction or loss
         (whether or not covered by insurance) or any  acquisition  or taking of
         property by any Authority;

                  (g) has not waived any rights of material  value  without fair
         and adequate consideration;

                  (h) has not experienced any work stoppage;

                  (i) except in the ordinary course of business, has not entered
         into,  amended or  terminated  any Lease,  Governmental  Authorization,
         Private Authorization, Material Agreement or Employment Arrangement, or
         any transaction, agreement or arrangement with any Affiliate of Gearon;

                  (j) has not made, paid or declared any Distribution; and

                  (k) has not entered  into any other  transaction  or series of
         related transactions which individually or in the aggregate is material
         to the Gearon Assets or the Gearon Business.

         4.17  Material  and Adverse  Restrictions.  Gearon is not a party to or
subject  to, nor is any of the Gearon  Assets  subject to, any  Applicable  Law,
Governmental  Authorization,  Contractual  Obligation,  Employment  Arrangement,
Material  Agreement  or  Private  Authorization,  or  any  other  obligation  or
restriction of any kind or character, which now has or, as far as Gearon can now
reasonably foresee, at any time in the future, individually or in the aggregate,
is likely to have, any material adverse effect on Gearon, except as set forth in
Section 4.17 of the Gearon Disclosure Schedule.

         4.18  Broker or Finder.  No Person  assisted  in or  brought  about the
negotiation of this Agreement or the Merger in the capacity of broker,  agent or
finder or in any similar capacity on behalf of Gearon or the Gearon  Stockholder
which would entitle such Person to any compensation.

                                      -12-
<PAGE>

         4.19  Solvency.  As of the  execution  and delivery of this  Agreement,
Gearon is, and immediately  prior to and immediately  after giving effect to the
consummation of the Merger will be, solvent.

         4.20 Environmental  Matters.  With respect to the Gearon Assets and the
Gearon  Business,  except as set forth in Gearon  Disclosure  Schedule  4.20 (it
being understood that such Schedule 4.20 shall include the information set forth
in the Phase I and Phase II Environmental Assessments which Gearon shall provide
to ATSI and which it shall have a  reasonable  period to review  pursuant to the
provisions  of Section  11.14) and except as the following  representations  may
relate to the  operations or conduct of (i) the owners of any property  which is
leased by Gearon or (ii) the  clients  or  customers  of Gearon on any  property
which is owned or leased  by  Gearon,  in which  such  representations  shall be
limited to Gearon's knowledge, Gearon:

                  (a) has not been notified that it is potentially liable under,
         has not received any request for  information  or other  correspondence
         concerning its potential liability with respect to any site or facility
         under, and, to Gearon's  knowledge,  is not a "potentially  responsible
         party" under, the Comprehensive  Environmental  Response,  Compensation
         and  Liability  Act of 1980,  as  amended,  the  Resource  Conservation
         Recovery Act, as amended, or any similar state law;

                  (b) has not  entered  into or  received  any  consent  decree,
         compliance  order  or  administrative  order  issued  pursuant  to  any
         Environmental  Law, except such  Environmental  Permits,  applications,
         notices or other permits as do not and will not have, in the aggregate,
         any material adverse effect on Gearon;

                  (c) is  not a  party  in  interest  or in  default  under  any
         judgment,  order, writ,  injunction or decree of any Final Order issued
         pursuant to any Environmental Law;

                  (d) has  obtained all  Environmental  Permits  required  under
         Environmental  Laws, and has filed all applications,  notices and other
         documents  required to be filed prior to the date of this  Agreement to
         effect the timely renewal or issuance of all Environmental  Permits for
         the continued conduct of its business in the manner now conducted;

                  (e)  is in  compliance  in  all  material  respects  with  all
         Environmental  Laws,  and  is  not  the  subject  of  or,  to  Gearon's
         knowledge,  threatened  with any Legal  Action  involving  a demand for
         damages or other potential liability,  including any Lien, with respect
         to violations or breaches of any Environmental Law;

                  (f) has not conducted or received any site  assessment,  audit
         or other  investigation  as to  material  environmental  matters at any
         property currently owned, leased, operated or occupied by Gearon;

                  (g) has not installed or used any above ground or  underground
         storage  tanks,  friable  asbestos,  polychlorinated  biphenyls or urea
         formaldehyde foam insulation on any property currently owned, leased or
         operated  by Gearon  and,  to  Gearon's  knowledge,  there are no above
         ground or underground storage tanks, friable asbestos,  polychlorinated
         biphenyls  or  urea   formaldehyde  foam  insulation  or  any  property
         currently owned, leased or operated by Gearon;

                  (h) has no knowledge of any past or present  Event  related to
         Gearon's properties,  operations or business, which Event, individually
         or in the aggregate,  may interfere with or prevent continued  material
         compliance with all  Environmental  Laws, or which,  individually or in
         the aggregate,  may form the basis of any material Claim for or arising
         out of the release or threatened  release into the  environment  of any
         Hazardous Material.

                                      -13-

<PAGE>

         4.21 Capital Stock.  The authorized  and  outstanding  capital stock of
Gearon is as set forth in Section 4.21 of the Gearon Disclosure Schedule. All of
such outstanding  capital stock has been duly authorized and validly issued,  is
fully paid and  nonassessable  and is not subject to any  preemptive  or similar
rights and is owned of record and, to Gearon's knowledge,  beneficially as shown
in Section  4.21 of the  Gearon  Disclosure  Schedule.  Except as  described  in
Section  4.21 of the  Gearon  Disclosure  Schedule,  Gearon  has not  granted or
issued, nor has Gearon agreed to grant or issue, any shares of its capital stock
or any Option Security or Convertible Security,  and Gearon is not a party to or
bound by any agreement,  put or commitment  pursuant to which it is obligated to
purchase,  redeem or otherwise acquire any shares of capital stock or any Option
Security or Convertible Security.

         4.22 Materiality.  The representations and warranties set forth in this
Article would in the aggregate be true and correct even without the  materiality
exceptions  or  qualifications  contained  therein  or set  forth in the  Gearon
Disclosure  Schedule,  except for such exceptions and  qualifications  including
without  limitation those set forth in the Gearon Disclosure  Schedule which, in
the aggregate for all such representations and warranties, are not and could not
reasonably be expected to be materially adverse to Gearon.


                                    ARTICLE 5

                 REPRESENTATIONS AND WARRANTIES OF ATS AND ATSI

         Each of ATS and ATSI,  jointly and  severally,  hereby  represents  and
warrants to Gearon and the Gearon Stockholder as follows:

         5.1  Organization  and  Business;   Power  and  Authority;   Effect  of
Transaction.

         (a)  Each of ATS and  ATSI is a  corporation  duly  organized,  validly
existing  and  in  good  standing  under  the  laws  of  its   jurisdiction   of
organization, has all requisite power and authority (corporate and other) to own
or hold under lease its properties and to conduct its business as now conducted.

         (b)  Each of ATS  and  ATSI  has  all  requisite  power  and  authority
(corporate  and  other)  and has in  full  force  and  effect  all  Governmental
Authorizations and Private Authorizations  necessary to enable it to execute and
deliver,  and  to  perform  its  obligations  under,  this  Agreement  and  each
Collateral Document executed or required to be executed by it pursuant hereto or
thereto or to  consummate  the  Transactions;  and the  execution,  delivery and
performance of this Agreement and each Collateral  Document executed or required
to be executed by it pursuant hereto or thereto have been duly authorized by all
requisite  corporate or other action on the part of ATS and ATSI. This Agreement
has been duly executed and delivered by ATS and ATSI and  constitutes,  and each
Collateral Document executed or required to be executed by each of them pursuant
hereto or thereto or to consummate the Transactions  when executed and delivered
by ATS and ATSI will constitute, legal, valid and binding obligations of each of
ATS and ATSI,  enforceable in accordance with their respective terms,  except as
such  enforceability  may be limited by bankruptcy,  moratorium,  insolvency and
similar laws  affecting the rights and remedies of creditors and  obligations of
debtors generally and by general principles of equity.

         (c) Except to the extent specifically  described in the ATS Information
Statement,  neither the execution and delivery by ATS and ATSI of this Agreement
or any Collateral  Document  executed or required to be executed by each of them
pursuant  hereto or  thereto,  nor the  consummation  of the  Transactions,  nor
compliance  with the terms,  conditions and provisions  hereof or thereof by ATS
and ATSI:

                                      -14-

<PAGE>

                  (i) will conflict with, or result in a breach or violation of,
         or constitute a default under,  any Organic  Document of ATS or ATSI or
         any  Applicable  Law, or will  conflict  with, or result in a breach or
         violation of, or constitute a default under, or permit the acceleration
         of any obligation or liability in, or but for any requirement of giving
         of notice or passage of time or both would  constitute  such a conflict
         with,  breach or  violation  of, or default  under,  or permit any such
         acceleration in, any Contractual Obligation of ATS or ATSI; or

                  (ii)  will   require  ATS  or  ATSI  to  make  or  obtain  any
         Governmental    Authorization,    Governmental    Filing   or   Private
         Authorization  including  without  limitation  under the FCA, except as
         required  by  the  Hart-Scott-Rodino  Act  or as  contemplated  by  the
         Registration Rights Agreement.

         5.2 Financial and Other  Information.  ATS has heretofore  furnished to
Gearon  copies of the ATS  Information  Statement.  The  consolidated  financial
statements of ATS included in the ATS Information  Statement (the "ATS Financial
Statements"),  including in each case the notes  thereto,  have been prepared in
accordance  with GAAP  applied on a  consistent  basis  throughout  the  periods
covered  thereby,  except as otherwise  noted  therein,  are true,  accurate and
complete in all  material  respects,  do not contain any untrue  statement  of a
material  fact or omit to state a material  fact  required  by GAAP to be stated
therein or  necessary  in order to make the  statements  contained  therein  not
misleading,  and fairly  present the  consolidated  financial  condition and the
consolidated  results of  operations  and cash flow of ATS, on the bases therein
stated,  as of the  respective  dates thereof,  and for the  respective  periods
covered  thereby  subject,  in the case of unaudited  financial  statements,  to
normal nonmaterial year-end audit adjustments and accruals.

         5.3 Material Statements and Omissions;  Absence of Events.  Neither any
representation  or warranty made by ATS or ATSI  contained in this  Agreement or
any certificate,  document or other  instrument  furnished or to be furnished by
ATS or ATSI pursuant to the provisions hereof nor the ATS Information  Statement
contains or will  contain any untrue  statement  of a material  fact or omits or
will omit to state any material fact  required to make any  statement  contained
herein or therein not  misleading.  Since the date of the most recent  financial
statements  constituting a part of the ATS Financial  Statements,  except to the
extent specifically described in the ATS Information  Statement,  there has been
no  material  adverse  change  in ATS.  There  is no Event  known  to ATS  which
materially  adversely affects,  or (so far as ATS can now reasonably foresee) is
likely to materially  adversely affect,  ATS, except to the extent  specifically
described in the ATS Information Statement. ATS is not aware of any impending or
contemplated  Event that would cause any of the  representations  and warranties
made by it in this  Article not to be true,  correct and complete on the date of
such Event as if made on that date.

         5.4 Absence of Sensitive  Payments.  Neither ATS, ATSI nor, to ATS' and
ATSI's knowledge, any of their officers,  directors,  employees, agents or other
representatives, has with respect to the assets and business of ATS and ATSI (a)
made any  contributions,  payments  or gifts  to or for the  private  use of any
governmental official, employee or agent where either the payment or the purpose
of such  contribution,  payment or gift is illegal  under the laws of the United
States or the  jurisdiction  in which made or (b)  established or maintained any
unrecorded fund or asset for any illegal purpose or made any false or artificial
entries on its books.

         5.5 Title to  Properties;  Leases.  ATSI has, to ATS'  knowledge,  good
indefeasible,  marketable and insurable  title to all real property  (other than
leasehold real property) and good  indefeasible  and  merchantable  title to all
other assets (other than real property), tangible and intangible, constituting a
part of the ATSI Assets; all of such real property and other assets is so owned,
in each case, free and clear of all Liens,  except 

                                      -15-


<PAGE>

(i) Permitted  Liens,  (ii) Liens set forth or described in the ATS  Information
Statement,  and (iii) Liens that would not,  individually  or in the  aggregate,
have a material adverse effect on ATS.

         5.6  Compliance  with  Private  Authorizations.  ATSI has  obtained all
Private Authorizations which are necessary for the ownership or operation of its
assets or the conduct of its business  which,  if not  obtained and  maintained,
could, individually or in the aggregate, materially adversely affect ATS. All of
such Private Authorizations are valid and in good standing and are in full force
and  effect.  ATSI is not in  breach  or  violation  of,  or in  default  in the
performance,  observance or fulfillment of, any such Private Authorization,  and
no Event exists or has occurred,  which constitutes,  or but for any requirement
of giving of notice or passage of time or both would constitute,  such a breach,
violation  or default,  under any such  Private  Authorization,  except for such
defaults,  breaches or  violations  as do not and will not have in the aggregate
any  material  adverse  effect on ATS. No such  Private  Authorization  which is
material  to the  ownership  and  operation  of ATSI's  assets or the conduct of
ATSI's  business  is the  subject  of  any  pending  or,  to  ATSI's  knowledge,
threatened attack, revocation or termination.

         5.7 Compliance with Governmental Authorizations and Applicable Law.

         (a)  ATSI  has  obtained  all  Governmental  Authorizations  which  are
necessary  for the  ownership  or  operation of its assets or the conduct of its
business as now  conducted  and which,  if not obtained and  maintained,  would,
individually or in the aggregate,  have any material adverse effect on ATS. None
of ATSI's  Governmental  Authorizations  which is material to the  ownership and
operation of ATSI's  assets or the conduct of ATSI's  business is subject to any
restriction  or  condition  which would limit in any  respect the  ownership  or
operations  of ATSI's  assets or the conduct of ATSI 's  business  as  currently
conducted,  except for restrictions  and conditions (i) generally  applicable to
Governmental  Authorizations of such type, and (ii) that would not, individually
or in the aggregate,  have a material adverse effect on ATS. ATSI's Governmental
Authorizations  which are  material to the  ownership  and  operation  of ATSI's
assets or the conduct of ATSI's business are valid and in good standing,  are in
full force and effect and are not impaired in any material respect by any act or
omission  of ATSI or its  officers,  directors,  employees  or  agents,  and the
ownership or operation of ATSI's assets or the conduct of ATSI's business are in
accordance in all material  respects with the Governmental  Authorizations.  All
material  reports,  forms and  statements  required to be filed by ATSI with all
Authorities  with  respect  to ATSI's  business  have  been  filed and are true,
complete and accurate in all material  respects.  No Governmental  Authorization
which is material to the ownership and operation of ATSI's assets or the conduct
of ATSI's  business  is the  subject  of any  pending  or, to ATSI's  knowledge,
threatened  challenge or proceeding to revoke or terminate any such Governmental
Authorization.  ATSI  has no  reason  to  believe  that  any  such  Governmental
Authorization would not be renewed in the name of ATSI by the granting Authority
in the ordinary course.

         (b) Except as otherwise  specifically  described in the ATS Information
Statement,  neither  ATS or  ATSI  nor  any  director  or  officer  thereof  (in
connection  with the  ownership or operation of ATSI's  assets or the conduct of
ATSI's  business) is in or is charged by any Authority  with or is threatened or
under investigation by any Authority with respect to, breach or violation of, or
default in the  performance,  observance  or  fulfillment  of, any  Governmental
Authorization  or any  Applicable Law relating to the ownership and operation of
ATSI's assets or the conduct of ATSI's business which, if determined  adversely,
individually or in the aggregate,  would have a material adverse effect on ATSI.
In particular,  but without limiting the generality of the foregoing,  there are
no  applications,  Claims  or  Legal  Actions  pending  or,  to ATS'  knowledge,
threatened before or by any Authority (x) relating to the ownership or operation
of the ATS assets or the conduct of the ATS business  which,  individually or in
the aggregate,  are reasonably likely to result in the revocation or termination
of any Governmental Authorization or the imposition of any restriction of such 

                                      -16-


<PAGE>

a nature as would adversely  affect the ownership or operation of the ATS assets
or  the  conduct  of  the  ATS  business;   (y)  involving  charges  of  illegal
discrimination  by ATS  under  any  federal  or state  employment  Laws,  or (z)
involving  Environmental  Laws  or  zoning  laws,  except,  in each  case,  such
applications,  Claims or Legal Actions as do not and will not have, individually
or in the aggregate, any material adverse effect on ATS.

         (c) Except as otherwise  specifically  described in the ATS Information
Statement,  no  Event  exists  or  has  occurred,   which,  to  ATS'  knowledge,
constitutes,  or but for any  requirement of giving of notice or passage of time
or both would  constitute,  such a breach,  violation or default,  under (i) any
Governmental   Authorization  or  any  Applicable  Law,  or  (ii)  any  material
requirement of any insurance carrier,  applicable to the ownership or operations
of the ATS assets or the conduct of the ATS business,  except, in each case, for
such breaches,  violations or defaults as do not and will not have, individually
or in the aggregate, any material adverse effect on ATS.

         5.8 Related Transactions. Neither ATS nor ATSI is a party or subject to
any  Contractual  Obligation  relating to the  ownership  or operation of ATSI's
assets or the conduct of ATSI's  business  between either of them and any of its
officers,  directors,  stockholders,  employees or, to the knowledge of ATS, any
Affiliate  of  any  thereof,   including  without   limitation  any  Contractual
Obligation  providing  for the  furnishing  of services to or by,  providing for
rental of property,  real,  personal or mixed,  to or from, or providing for the
lending or borrowing of money to or from or otherwise  requiring  payments to or
from,  any such  Person,  other than those  described  or referred to in the ATS
Information  Statement  or  that  are  not,  individually  or in the  aggregate,
material to the business of ATS or ATSI.

         5.9 Tax  Matters.  Each of ATS and  ATSI  has in  accordance  with  all
Applicable  Laws filed all Tax Returns  which are required to be filed,  and has
paid, or made adequate provision for the payment of, all Taxes which have or may
become due and payable  pursuant to said Tax Returns and all other  governmental
charges and assessments  received to date other than those Taxes being contested
in good  faith for which  adequate  provision  has been made on the most  recent
balance sheet forming part of ATS Financial  Statements.  The Tax Returns of ATS
and ATSI have been  prepared in all  material  respects in  accordance  with all
Applicable  Laws  and  generally  accepted  principles  applicable  to  taxation
consistently  applied.  All  Taxes  which  ATS and  ATSI is  required  by law to
withhold and collect have been duly withheld and  collected,  and have been paid
over,  in a timely  manner,  to the  proper  Authorities  to the  extent due and
payable.  Adequate  provision  has been made on the most  recent  balance  sheet
forming part of ATS Financial  Statements for all Taxes accrued through the date
of such balance sheet of any kind,  including  interest and penalties in respect
thereof, whether disputed or not, and whether past, current or deferred, accrued
or unaccrued,  fixed,  contingent,  absolute or other,  and there are, to ATSI's
knowledge,  no past  transactions  or matters  which could result in  additional
Taxes of a material  nature to ATSI for which an  adequate  reserve has not been
provided on such balance sheet.

         5.10 Ordinary Course of Business. Each of ATS and ATSI, from the end of
its  most  recent  fiscal  quarter  to the  date  hereof,  except  (i) as may be
described  in the ATS  Information  Statement,  or (ii)  as may be  required  or
expressly contemplated by the terms of this Agreement, has operated its business
in all  material  respects  in the  normal,  usual and  customary  manner in the
ordinary and regular  course of business,  consistent  with prior  practice,  it
being  understood  that  the  acquisition  of  communications  sites  and  other
companies and assets  involved in the  communications  sites industry is part of
the ordinary course of business of each of ATS and ATSI.

         5.11  Environmental  Matters.  Except  for such  matters  as would not,
individually or in the aggregate, have a material adverse effect on ATS, ATSI


                                      -17-


<PAGE>

                  (a) has not been notified that it is potentially liable under,
         has not received any request for  information  or other  correspondence
         concerning its potential liability with respect to any site or facility
         under,  and, to ATSI's  knowledge,  is not a  "potentially  responsible
         party" under, the Comprehensive  Environmental  Response,  Compensation
         and  Liability  Act of 1980,  as  amended,  the  Resource  Conservation
         Recovery Act, as amended, or any similar state law;

                  (b) has not  entered  into or  received  any  consent  decree,
         compliance  order  or  administrative  order  issued  pursuant  to  any
         Environmental Law;

                  (c) is  not a  party  in  interest  or in  default  under  any
         judgment,  order, writ,  injunction or decree of any Final Order issued
         pursuant to any Environmental Law;

                  (d) has  obtained all  Environmental  Permits  required  under
         Environmental  Laws, and has filed all applications,  notices and other
         documents  required to be filed prior to the date of this  Agreement to
         effect the timely renewal or issuance of all Environmental  Permits for
         the continued conduct of its business in the manner now conducted;

                  (e)  is in  compliance  in  all  material  respects  with  all
         Environmental  Laws, and is not the subject of or, to ATSI's knowledge,
         threatened  with any Legal  Action  involving  a demand for  damages or
         other  potential  liability,   including  any  Lien,  with  respect  to
         violations or breaches of any Environmental Law;

                  (f) has not conducted or received any site  assessment,  audit
         or other  investigation  as to  material  environmental  matters at any
         property currently owned, leased, operated or occupied by ATSI;

                  (g) has not installed or used any above ground or  underground
         storage  tanks,  friable  asbestos,  polychlorinated  biphenyls or urea
         formaldehyde foam insulation on any property currently owned, leased or
         operated by ATSI and, to ATSI's knowledge, there are no above ground or
         underground storage tanks, friable asbestos,  polychlorinated biphenyls
         or urea formaldehyde  foam insulation or any property  currently owned,
         leased or operated by ATSI;

                  (h) there has been no  disposal,  release,  spill or burial of
         any Hazardous Materials by ATSI (or any Person acting on its behalf) in
         violation  of  Environmental  Laws on any  property or facility  owned,
         leased,  operated  or occupied  by ATSI or to ATSI's  knowledge  at any
         facility or site to which Hazardous Materials from or generated by ATSI
         may have been taken at any time in the past;

                  (i) to ATSI's knowledge, there has been no disposal,  release,
         spill or  burial  of any  Hazardous  Materials  by ATSI (or any  Person
         acting  on its  behalf)  on any  property  which  could  reasonably  be
         expected to result or has  resulted  in  contamination  which  requires
         investigation, remediation or other response activity on or beneath any
         properties or facilities currently owned, leased,  operated or occupied
         by ATSI; and

                  (j) has no knowledge of any past or present  Event  related to
         ATSI's properties, operations or business, which Event, individually or
         in the  aggregate,  may interfere  with or prevent  continued  material
         compliance with all  Environmental  Laws, or which,  individually or in
         the aggregate,  may form the basis of any material Claim for or arising
         out of the release or threatened  release into the  environment  of any
         Hazardous Material.

                                      -18-


<PAGE>


         5.12 Materiality.  The representations and warranties set forth in this
Article would in the aggregate be true and correct even without the  materiality
exceptions  or  qualifications  contained  therein,  or set  forth  in  the  ATS
Information Statement,  except for such exceptions and qualifications  including
without  limitation  those set forth in the ATS Information  Statement which, in
the aggregate for all such representations and warranties, are not and could not
reasonably be expected to be materially adverse to ATS.

         5.13 Material and Adverse Restrictions. Neither ATS nor ATSI is a party
to or  subject  to,  nor is any of the  assets of ATS or ATSI  subject  to,  any
Applicable Law, governmental authorization,  contractual obligation,  employment
arrangement,   material  agreement  or  private  authorization,   or  any  other
obligation or restriction of any kind or character,  which now has or, as far as
ATS or ATSI can now reasonably foresee, at any time in the future,  individually
or in the aggregate,  is likely to have,  any material  adverse effect on ATS or
ATSI, except as set forth in the ATS Information Statement.

         5.14  Broker or Finder.  No Person  assisted  in or  brought  about the
negotiation  of this  Agreement or the  Transactions  in the capacity of broker,
agent or finder or in any similar capacity on behalf of ATS or ATSI.

         5.15 Solvency. As of the execution and delivery of this Agreement, each
of ATS and ATSI is, and immediately prior to and immediately after giving effect
to the consummation of the Transactions will be, solvent.

         5.16 Capital Stock.

         (a) The authorized and outstanding capital stock of ATS is as set forth
in the ATS  Information  Statement.  All of such  outstanding  capital stock has
been,  and,  when issued in  accordance  with the terms of this  Agreement,  the
Common Stock  Consideration  will be, duly authorized and validly issued,  fully
paid and  nonassessable  and is not subject to any preemptive or similar rights.
Except as described  in the ATS  Information  Statement,  ATS has not granted or
issued, nor has ATS agreed to grant or issue, any shares of its capital stock or
any Option Security or Convertible Security,  and ATS is not a party to or bound
by any  agreement,  put or  commitment  pursuant  to  which it is  obligated  to
purchase,  redeem or otherwise acquire any shares of capital stock or any Option
Security or Convertible Security.

         (b) All of the issued and outstanding capital stock of ATSI is owned by
ATS. ATS has no plan or intention (i) to cause ATSI to issue  additional  shares
of its capital  stock that would result in ATS' losing  "control" of ATSI within
the meaning of Section  368(c) of the Code;  (ii) to  liquidate  ATSI;  (iii) to
merge ATSI with and into another  corporation other than as contemplated by this
Agreement (and certain other  potential  transaction  which would not,  however,
involve the issuance by ATSI of any securities to parties other than ATS);  (iv)
to sell or otherwise  dispose of any capital stock of ATSI; or (v) to cause ATSI
to sell or  otherwise  dispose  of any of the  assets of  Gearon to be  acquired
pursuant to the Merger,  except for dispositions  made in the ordinary course of
business or transfers described in Section  368(a)(2)(C) of the Code.  Following
the  Merger,  ATSI will  continue  the  historical  business  of Gearon or use a
significant portion of the Gearon Assets in its business.

         5.17 Employment  Arrangements.  Neither ATS nor ATSI has any obligation
or liability,  contingent or other,  under any employment  arrangement  with any
employee of ATS or ATSI, other than (i) those incurred in the ordinary and usual
course of business,  or (ii) such  obligations or liabilities as do not and will
not have, in the aggregate,  any material adverse effect on ATS or ATSI.  Except
as described in the ATS Information Statement,  (a) none of the employees of ATS
or ATSI is now, or since January 1, 1995 has been,

                                      -19-


<PAGE>



represented  by  any  labor  union  or  other  employee  collective   bargaining
organization,  and neither ATS nor ATSI is, nor have they ever been,  a party to
any labor or other  collective  bargaining  agreement with respect to any of the
employees  of ATS or ATSI,  (b) there are no  pending  grievances,  disputes  or
controversies  with any union or any other  employee  or  collective  bargaining
organization  of such  employees,  or  threats of  strikes,  work  stoppages  or
slowdowns or any pending demands for collective  bargaining by any such union or
other organization,  and (c) neither ATS, ATSI nor any of such employees is now,
or has since  January 1, 1995 been,  subject  to or  involved  in or, to ATS' or
ATSI's knowledge,  threatened with, any union elections,  petitions  therefor or
other organizational or recruiting activities, in each case with respect to such
employees.  Each of ATS and ATSI has  performed  in all  material  respects  all
obligations  required to be performed under all Employment  Arrangements  and is
not in material  breach or violation of or in material  default or arrears under
any of the terms, provisions or conditions thereof.

         5.18 Investment Representation.

         (a) ATSI is an  "accredited  investor"  within the  meaning of Rule 501
promulgated  under the Securities Act and has been furnished with and had access
to all  information,  financial  and  other,  and  has  the  opportunity  to ask
questions of the management of Gearon with respect to Gearon and ATSI's proposed
investment therein.

         (b) ATSI is  acquiring  the Gearon  Notes to be purchased by it for its
own  account  for  investment  with no  present  intention  of  distributing  or
reselling the same, subject, nevertheless, to its right to dispose of the Gearon
Notes or any  part  thereof  in its sole  discretion;  provided,  however,  that
notwithstanding the foregoing, ATSI may pledge any or all of the Gearon Notes to
any bona fide lender to ATSI. ATSI  understands  that Gearon is not and will not
be  required  to file a  registration  statement  under  the  Securities  Act in
connection with any sale, transfer or other disposition of the Gearon Notes.

         5.19 Covenant  Regarding  Transfer.  ATSI  covenants and agrees that it
will not sell, assign,  transfer or otherwise dispose of any of the Gearon Notes
in violation of the Securities Act.


                                    ARTICLE 6

            REPRESENTATIONS AND WARRANTIES OF THE GEARON STOCKHOLDER
                          RELATING TO THE SUBJECT STOCK

         The  Gearon  Stockholder  represents  and  warrants  to ATS and ATSI as
follows:

         6.1 Enforceability. This Agreement has been duly executed and delivered
by the Gearon Stockholder and constitutes, and each Collateral Document executed
or required to be executed by such  Stockholder  pursuant hereto or thereto when
executed and delivered by the Gearon  Stockholder will constitute,  legal, valid
and binding  obligations  of the Gearon  Stockholder,  enforceable in accordance
with their respective  terms,  except as such  enforceability  may be subject to
bankruptcy,  moratorium,  insolvency,   reorganization,   arrangement,  voidable
preference,  fraudulent  conveyance  and  other  similar  laws  relating  to  or
affecting  the rights of creditors  and except as the same may be subject to the
effect of general principles of equity.

         6.2 Title to Shares.  The Gearon Stockholder owns the Gearon Shares set
forth  opposite  his name in  Section  4.21 of the Gearon  Disclosure  Schedule.
Except as set forth in Section 4.21 of the Gearon

                                      -20-


<PAGE>

Disclosure  Schedule,  the Gearon  Stockholder  owns and has good and marketable
title to such Gearon Shares as so set forth, free and clear of all Liens.

         6.3 No Conflict;  Required Filings and Consents. Except for consents as
set forth in  Section  4.1(c) of the Gearon  Disclosure  Schedule,  neither  the
execution  and  delivery  by the Gearon  Stockholder  of this  Agreement  or any
Collateral   Document  executed  or  required  to  be  executed  by  the  Gearon
Stockholder   pursuant   hereto  or  thereto,   nor  the   consummation  of  the
Transactions, nor compliance with the terms, conditions and provisions hereof or
thereof by the Gearon Stockholder:

                  (i) will conflict with, or result in a breach or violation of,
         or constitute a default  under,  any  Applicable  Law, or will conflict
         with,  or result in a breach or violation  of, or  constitute a default
         under, or permit the acceleration of any obligation or liability in, or
         but for any  requirement  of the giving of notice or passage of time or
         both would constitute such a conflict with,  breach or violation of, or
         default  under,  or  permit  any   acceleration   in,  any  Contractual
         Obligation of the Gearon Stockholder;

                  (ii) will result in or permit the  creation or  imposition  of
         any Lien upon any property or asset of the Gearon  Stockholder,  except
         for  such  Liens  as do not and  will not  have,  in the  aggregate,  a
         material adverse effect on the Gearon Stockholder; or

                  (iii)  will   require  any   Governmental   Authorization   or
         Governmental Filing or Private Authorization of the Gearon Stockholder,
         except as required by the Hart-Scott-Rodino Act.


                                    ARTICLE 7

                                    COVENANTS

         7.1 Access to Information; Confidentiality.

         (a) Each party  shall  afford to the other  party and its  accountants,
counsel,  financial advisors and other  representatives (the  "Representatives")
full access  during normal  business  hours  throughout  the period prior to the
Closing Date to all of its (and its Subsidiaries') properties, books, contracts,
commitments and records  (including  without limitation Tax Returns) and, during
such  period,  shall  furnish  promptly  upon request (i) a copy of each report,
schedule  and other  document  filed or  received  by any party  pursuant to the
requirements  of any Applicable Law  (including  without  limitation the FCA) or
filed by it with any  Authority  in  connection  with the  Merger  or any  other
report,  schedule  or  documents  which  may  have  a  material  effect  on  the
businesses,  operations, properties, prospects, personnel, condition, (financial
or other), or results of operations of their respective businesses,  (ii) to the
extent not provided for pursuant to the preceding clause, all financial records,
ledgers,  work papers and other  sources of financial  information  possessed or
controlled by it or its accountants deemed by each party or its  Representatives
necessary or useful for the purpose of  performing  an audit of the business and
assets of Gearon and ATS, as  applicable,  and,  in the case of ATS,  certifying
financial  statements  and financial  information  pursuant to the provisions of
Section 8.2(g), and (iii) such other information concerning any of the foregoing
as  ATS  or  Gearon  shall  reasonably  request.  All  Confidential  Information
furnished  pursuant  to the  provisions  of this  Agreement,  including  without
limitation this Section,  will be kept  confidential  and shall not, without the
prior written consent of the party disclosing such Confidential Information,  be
disclosed by the other party in any manner whatsoever, in whole or in part, and,
except as required by Applicable Law (including without limitation in connection
with any registration, 

                                      -21-


<PAGE>


proxy or information statement or similar document filed pursuant to any federal
or state  securities  Law)  shall not be used for any  purposes,  other  than in
connection  with the Merger.  Except as otherwise  herein  provided,  each party
agrees  to  reveal  such   Confidential   Information   only  to  those  of  its
Representatives or other Persons who need to know such Confidential  Information
for the purpose of evaluating  and  consummating  the Merger who are informed of
its  confidential   nature.  For  purposes  of  this  Agreement,   "Confidential
Information" shall mean any and all information  (excluding information that (i)
has been or is obtained from a source  independent of the disclosing party, (ii)
is or  becomes  generally  available  to the  public  other  than as a result of
unauthorized  disclosure  by the  receiving  party,  or (iii)  is  independently
developed by the  receiving  party  without  reliance in any way on  information
provided by the disclosing  party) related to the business or businesses of ATS,
ATSI and  their  respective  Affiliates,  on the one  hand,  or  Gearon  and its
Affiliates,  on the other hand, including any of their respective successors and
assigns.  For the period  beginning on the date of this  Agreement and ending on
the earlier to occur of (A) the  Closing  Date and (B) the date that is eighteen
(18) months from the date this Agreement is terminated, ATS and ATSI, on the one
hand,  and Gearon  and the Gearon  Stockholder,  on the other  hand,  agree that
neither it nor any of its  Affiliates  will solicit or actively seek to hire any
person who during  such  period is employed by the other party (or any of them),
whether  or not such  individual  would  commit a  breach  of such  individual's
employment agreement or contract in leaving such employment;  provided, however,
that the  foregoing  shall not  prevent any party (or its  Affiliates)  from (i)
taking any such  action  with  respect to any person who is not  employed by the
other party on the date the first such action is taken,  or (ii) placing general
advertisements in the media.

         (b)  Notwithstanding  the provisions of Section 7.1(a),  each party may
disclose  such  information  as it may  reasonably  determine to be necessary in
connection with seeking all Governmental and Private  Authorizations  or that is
required by Applicable Law to be disclosed,  including without limitation in any
registration,  proxy or information  statement or other document  required to be
filed  under  any  federal  or state  securities  Law.  In the  event  that this
Agreement is terminated in accordance with its terms,  each party shall promptly
redeliver all written Confidential Information provided pursuant to this Section
or any other  provision of this  Agreement or otherwise in  connection  with the
Merger and shall not retain any copies, extracts or other reproductions in whole
or in part of such written material,  other than one copy thereof which shall be
delivered to independent counsel for such party.

         (c) No investigation pursuant to this Section or otherwise shall affect
any  representation  or warranty in this Agreement of any party or any condition
to the obligations of the parties hereto.

         7.2 Agreement to Cooperate.

         (a) Each of the parties  hereto shall use reasonable  business  efforts
(x) to take,  or cause to be taken,  all actions and to do, or cause to be done,
all things necessary, proper or advisable under Applicable Law to consummate the
Merger,  and (y) to refrain from taking, or cause to be taken, any action and to
refrain from doing or causing to be done,  anything which could impede or impair
the  consummation of the Merger or the  consummation of the other  Transactions,
including,  in all  cases,  without  limitation  using its  reasonable  business
efforts (i) to prepare and file with the  applicable  Authorities as promptly as
practicable after the execution of this Agreement all requisite applications and
amendments  thereto,  together  with  related  information,  data and  exhibits,
necessary  to  request  issuance  of  orders  approving  the  Merger by all such
applicable  Authorities,  (ii) to obtain all necessary or  appropriate  waivers,
consents and approvals, (iii) to effect all necessary registrations, filings and
submissions (including without limitation, if required,  filings within five (5)
business days of the date of this Agreement under the  Hart-Scott-Rodino Act and
all filings  necessary  for ATSI to own and  operate  the Gearon  Assets and the
Gearon  Business),  (iv) to lift any injunction or other legal bar to the Merger
(and,  in such case, to proceed with the Merger as  expeditiously  as possible),
and (v) 

                                      -22-


<PAGE>

to obtain the  satisfaction of the conditions  specified in Article 8, including
without  limitation the truth and  correctness as of the Closing Date as if made
on and as of the Closing  Date of the  representations  and  warranties  of such
party  and  the  performance  and  satisfaction  as of the  Closing  Date of all
agreements and conditions to be performed or satisfied by such party.

         (b) The parties shall  cooperate with one another in the preparation of
all Tax Returns,  questionnaires,  applications or other documents regarding any
Taxes or transfer, recording, registration or other fees which become payable in
connection  with the  Merger  that are  required  to be filed on or  before  the
Closing Date.

         (c) Gearon shall cooperate and use its reasonable  business  efforts to
cause its independent  accountants to reasonably cooperate with ATS, and at ATS'
expense,  in order to enable ATS to have Gearon or ATS' independent  accountants
prepare  audited  financial  statements for Gearon  described in Section 8.2(g).
Gearon and the Gearon Stockholder,  jointly and severally, represent and warrant
that such financial  statements  will have been prepared in accordance with GAAP
applied on a basis  consistent  with the Gearon  Financial  Statements  and will
present  fairly the financial  condition,  results of operation and cash flow of
Gearon. Without limiting the generality of the foregoing,  Gearon agrees that it
will  (i)  consent  to the  use of  such  audited  financial  statements  in any
registration,  proxy or information  statement or other document filed by ATS or
any of its  Affiliates  under the  Securities  Act or the  Exchange Act and (ii)
execute  and  deliver,  and cause its  officers  to execute  and  deliver,  such
"representation"  letters as are customarily delivered in connection with audits
and as ATS' or Gearon's independent accountants may reasonably request under the
circumstances.

         7.3 Public Announcements.  Until the Closing or the termination of this
Agreement,  each party shall  consult  with the other  before  issuing any press
release or otherwise making any public statements with respect to this Agreement
or the Merger and shall not issue any such press release or make any such public
statement without the prior consent of the other. Notwithstanding the foregoing,
the parties  acknowledge  and agree that they may,  without each  other's  prior
consent,  issue such press  releases  or make such public  statements  as may be
required by Applicable Law, in which case, to the extent practicable,  they will
consult  with the other  regarding  the  nature,  content and form of such press
release or public statement.

         7.4  Notification  of Certain  Matters.  Each party  shall give  prompt
notice  to the  other,  of the  occurrence  or  non-occurrence  of any Event the
occurrence or  non-occurrence  of which would be reasonably  likely to cause (a)
any  representation  or warranty  made by it contained  in this  Agreement to be
untrue or  inaccurate  in any material  respect or (b) any failure made by it to
comply with or satisfy,  or be able to comply with or satisfy,  in any  material
respect,  any covenant,  condition or agreement to be complied with or satisfied
by it under this Agreement in any material respect, such that, in any such case,
one or more of the  conditions  of  Closing  would not be  satisfied;  provided,
however,  that the  delivery of any notice  pursuant to this  Section  shall not
limit or  otherwise  affect the rights and remedies  available  hereunder to the
party  receiving  such notice or the  obligations of the party  delivering  such
notice and shall  not,  in any event,  affect the  representations,  warranties,
covenants and  agreements of the parties or the  conditions to their  respective
obligations under this Agreement.

         7.5 No Solicitation.  Neither Gearon nor the Gearon  Stockholder shall,
nor  shall  it or any  of  them  knowingly  permit  any  of its or any of  their
Representatives  (including,  without limitation, any investment banker, broker,
finder,  attorney or  accountant  retained  by it or any of them) to,  initiate,
solicit or facilitate,  directly or  indirectly,  any inquiries or the making of
any  proposal  with  respect  to  any  Alternative  Transaction,  engage  in any
discussions  or  negotiations  concerning,  or provide  to any other  Person any
information or data 

                                      -23-

<PAGE>

relating to, it for the  purposes of, or otherwise  cooperate in any way with or
assist or  participate  in, or  facilitate  any  inquiries  or the making of any
proposal which constitutes, or may reasonably be expected to lead to, a proposal
to seek or  effect  any  Alternative  Transaction,  or agree to or  endorse  any
Alternative Transaction. "Alternative Transaction" means a transaction or series
of related transactions (other than the Transactions)  resulting in or likely to
result in (i) any change of control of Gearon, (ii) any merger, consolidation or
other  business  combination  of Gearon,  regardless  of  whether  Gearon is the
surviving  Entity  unless the  surviving  Entity  remains  obligated  under this
Agreement  to the same extent as Gearon was,  (iii) any tender offer or exchange
offer for, or any  acquisitions  of, any securities of Gearon,  (iv) any sale or
other  disposition of all or any  substantial  part of the assets or business of
Gearon,  (v) any issue or sale, or any  agreement to issue or sell,  any capital
stock,  Convertible Securities or Option Securities by Gearon, or (vi) any sale,
transfer,  pledge,  assignment  or other  conveyance  or any  agreement to sell,
transfer,  pledge,  assign or otherwise convey,  any Gearon Shares,  Convertible
Securities or Option Securities of Gearon. If Gearon,  the Gearon Stockholder or
its or any of their  Representatives  receives  any inquiry  with  respect to an
Alternative  Transaction while this Agreement is in effect, Gearon or the Gearon
Stockholder  shall inform the  inquiring  party that it is not entitled to enter
into discussions or negotiations relating to an Alternative Transaction.

         7.6 Conduct of Business by ATSI Pending the Merger. Except as otherwise
contemplated by this Agreement,  or as has been publicly  disclosed prior to the
date hereof or is described  in the ATS  Information  Statement,  after the date
hereof and prior to the Closing Date or earlier  termination  of this  Agreement
unless Gearon shall otherwise agree in writing,  ATS shall,  and shall cause its
Subsidiaries, to:

                  (a) conduct  their  respective  businesses in the ordinary and
         usual  course of business  and  consistent  with past  practice,  which
         includes  the  acquisition  of  other   businesses  or  assets  in  the
         communications site industry;

                  (b) not  amend or  propose  to amend  its  Organic  Documents,
         except that ATS may amend its Restated  Certificate of Incorporation to
         change the  authorized  number of shares of capital stock and otherwise
         in a manner not adverse to the holders of the ATS Class A Common Stock;

                  (c) use reasonable  business  efforts to preserve intact their
         respective  business  organizations  and goodwill,  keep  available the
         services of their respective  present  officers and key employees,  and
         preserve the goodwill and business  relationships  with  customers  and
         others having  business  relationships  with them and not engage in any
         action, directly or indirectly, with the intent to adversely affect the
         transactions contemplated by this Agreement;

                  (d) confer on a regular  and  frequent  basis with one or more
         representatives of Gearon to report material operational matters; and

                  (e) not  authorize  or enter  into any  agreement  that  would
         violate any of the foregoing.

         7.7  Conduct of Business  by Gearon  Pending the Merger.  Except as set
forth  in  Section  7.7  of  the  Gearon  Disclosure  Schedule  or as  otherwise
contemplated by this  Agreement,  after the date hereof and prior to the Closing
Date or  earlier  termination  of this  Agreement,  unless  ATS shall  otherwise
consent in writing, Gearon shall:

                  (a) conduct its  business in the  ordinary and usual course of
         business  and   consistent   with  past  practice  which  includes  the
         acquisition and construction of communications sites and towers;



                                      -24-


<PAGE>

                  (b) not (i) amend or propose to amend their respective Organic
         Documents, (ii) split, combine or reclassify (whether by stock dividend
         or otherwise) its  outstanding  capital stock or issue or authorize the
         issuance  of any  other  securities  in  respect  of, in lieu of, or in
         substitution  for shares of its capital stock,  or (iii)  declare,  set
         aside or pay any  dividend  or  distribution  payable  in cash,  stock,
         property or otherwise;

                  (c) not issue,  sell, pledge or dispose of, or agree to issue,
         sell,  pledge  or  dispose  of,  any  shares of  Gearon  Common  Stock,
         Convertible Securities or Option Securities;

                  (d) not (i) incur or become  contingently  liable with respect
         to any indebtedness other than short-term  unsecured  borrowings not to
         exceed the excess of (x) $5,000,000 in the aggregate outstanding at any
         one time over (y) the principal  amount at the time  outstanding  under
         the Gearon Notes, (ii) redeem,  purchase,  acquire or offer to purchase
         or acquire any shares of its capital stock,  Convertible  Securities or
         Option Securities,  (iii) sell, lease, license,  pledge,  dispose of or
         encumber any  properties  or assets or sell any  businesses  other than
         pursuant  to  agreements  in effect on the date hereof and set forth in
         Section  7.7 of the  Gearon  Disclosure  Schedule  or Liens  arising in
         accordance  with the provisions of  indebtedness  in effect on the date
         hereof and in  accordance  with their present  terms,  or (iv) make any
         loans,  advances or capital  contributions  to, or investments  in, any
         other  Person,  except to officers and  employees of Gearon for travel,
         business or relocation expenses in the ordinary course of business;

                  (e) use  reasonable  business  efforts to preserve  intact its
         business organization and goodwill,  keep available the services of its
         present  officers  and key  employees,  and  preserve  the goodwill and
         business  relationships  with  customers  and  others  having  business
         relationships  with them and not  engage  in any  action,  directly  or
         indirectly,  with the  intent  to  adversely  impact  the  transactions
         contemplated by this Agreement;

                  (f) confer on a regular  and  frequent  basis with one or more
         representatives of ATS to report material  operational  matters and the
         general status of ongoing operations;

                  (g) not adopt,  enter into, amend or terminate any employment,
         severance,  special pay  arrangement  with  respect to  termination  of
         employment  or  other  similar  arrangements  or  agreements  with  any
         directors, officers or key employees;

                  (h) maintain with financially  responsible insurance companies
         insurance on the Gearon Assets and the Gearon  Business in such amounts
         and against such risks and losses as are consistent with past practice;

                  (i) not make any Tax election that could  reasonably be likely
         to have a material adverse effect on Gearon or settle or compromise any
         material income Tax liability;

                  (j) except in the  ordinary  course of  business  or except as
         would not  reasonably  be likely to have a material  adverse  effect on
         Gearon, not modify,  amend or terminate any Material Agreement to which
         Gearon is a party or by which any of the Gearon  Assets may be bound or
         to which any of them may be  subject  or waive,  release  or assign any
         material rights or claims thereunder;

                  (k) not make any material  change to its  accounting  methods,
         principles or practices, except as may be required by GAAP;

                                      -25-


<PAGE>

                  (l)  not  acquire  or  agree  to  acquire  (i) by  merging  or
         consolidating  with,  or by  purchasing  a  substantial  portion of the
         assets of, or by any other manner,  any business or any Person or other
         business  organization  or  division  thereof or (ii) any assets  that,
         individually or in the aggregate, are material to Gearon, in each case,
         other than  pursuant to agreements in effect on the date hereof and set
         forth in the Section 7.7 of the Gearon Disclosure  Schedule (ATS agrees
         not to  unreasonably  withhold,  delay or  condition  a consent  to any
         matters described in this paragraph);

                  (m) except as set forth in Section  4.6(a) or Section  4.14 of
         the Gearon Disclosure Schedule,  (i) not grant to any executive officer
         or other key  employee of Gearon any increase in  compensation,  except
         for normal increases in the ordinary course of business consistent with
         past practice or as required under Benefit Arrangements in effect as of
         September 30, 1997,  (ii) not grant to any such  executive  officer any
         increase in severance or termination  pay, except as was required under
         any Benefit  Arrangements in effect as of September 30, 1997, (iii) not
         adopt or amend any Plan or Benefit  Arrangement  (including  change any
         actuarial or other  assumption  used to calculate  funding  obligations
         with respect to any Plan,  or change the manner in which  contributions
         to any Plan are made or the  basis  on  which  such  contributions  are
         determined)  and (iv) except in the  ordinary  course,  not enter into,
         amend  in  any   material   respect  or  terminate   any   Governmental
         Authorization  (except  as would  not be  reasonably  likely  to have a
         material adverse effect on Gearon),  material Private  Authorization or
         Contract;

                  (n) not  voluntarily  take or permit  to be taken  any  action
         which if taken  between the end of its most recent  fiscal  quarter and
         prior to the date of this  Agreement  would  have been  required  to be
         noted  as an  exception  on  Section  4.16  of  the  Gearon  Disclosure
         Schedule,  other than  pursuant to the  conduct of its  business in the
         ordinary  and  usual  course  of  business  and  consistent  with  past
         practice; and

                  (o) not  authorize  or enter  into any  agreement  that  would
         violate any of the foregoing.

         7.8  Preliminary  Title Reports.  As promptly as practicable  after the
execution  of this  Agreement,  Gearon  shall,  at ATS' sole  cost and  expense,
deliver or cause to be delivered to ATS a standard preliminary title report (the
"Title  Reports")  dated on or after the date of this  Agreement  issued by such
title  company or companies as Gearon and ATS shall  mutually  reasonably  agree
with respect to those assets of Gearon comprised of the parcels of real property
owned by Gearon, as described in Section 7.8 of the Gearon Disclosure Schedule.

         7.9 Environmental  Site  Assessments.  As promptly as practicable after
the execution of this Agreement, ATS may at its own cost and expense obtain, and
deliver to Gearon  full and  complete  copies  of,  Phase I  environmental  site
assessment reports (the "Environmental  Reports") on any or all of those certain
parcels  of real  property  described  on Section  7.9 of the Gearon  Disclosure
Schedule.   Site  assessments   shall  be  conducted  by  such  consultants  and
professionals  as ATS and Gearon shall  mutually  agree and shall be arranged at
times  mutually  convenient  to the  parties.  Each of  Gearon  and ATS shall be
entitled to have  representatives  present at the time such site assessments are
conducted,  and to have  copies  of all  correspondence  with the  Environmental
Company.

         7.10 Interim Financing for Gearon.  ATSI agrees to provide interim debt
financing to Gearon in an aggregate  amount at any one time  outstanding  not to
exceed  $5,000,000  as from time to time  requested  on not less than  three (3)
business days notice from Gearon. Any such financing shall be advanced against a

                                      -26-


<PAGE>


secured note  substantially  in the form of Exhibit A attached hereto and made a
part hereof (the  "Gearon  Notes") and shall be secured by a security  agreement
substantially  in the form  attached  hereto as Exhibit B and made a part hereof
(the "Gearon Security Agreement").  Gearon shall use the proceeds of the sale of
the  Gearon  Notes  to  ATSI  hereunder  to  complete  the  development  of  new
communication  sites and  capital  improvements  to its  existing  communication
sites, and for other general corporate purposes (other than the repayment of any
Indebtedness for Money Borrowed).  The parties acknowledge that,  simultaneously
with the execution and delivery of this  Agreement,  (a) Gearon has executed and
delivered  the  Gearon  Note to ATSI,  (b)  Gearon  and ATSI have  executed  and
delivered the Security Agreement, and (c) ATSI has not advanced any funds.


                                    ARTICLE 8

                               CLOSING CONDITIONS

         8.1 Conditions to Obligations of Each Party. The respective obligations
of each party to effect the Merger shall, except as hereinafter provided in this
Section,  be subject to the  satisfaction at or prior to the Closing Date of the
following conditions, any or all of which may be waived, in whole or in part, to
the extent permitted by Applicable Law:

                  (a) As of the Closing  Date,  no Legal Action shall be pending
         before any  Authority  seeking to enjoin,  restrain,  prohibit  or make
         illegal or to impose any  materially  adverse  conditions in connection
         with,  the  consummation  of the Merger or the other  Transactions,  it
         being understood and agreed that a written request by any Authority for
         information with respect to the Merger, which information could be used
         in connection with such Legal Action,  shall not in itself be deemed to
         be a Legal Action pending before any such Authority; and

                  (b) All authorizations, consents, waivers, orders or approvals
         required  to  be  obtained  from  all  Authorities,  and  all  filings,
         submissions, registrations, notices or declarations required to be made
         by any of the parties with any Authority,  prior to the consummation of
         the Merger,  shall have been  obtained  from,  and made with,  all such
         Authorities, except for such authorizations, consents, waivers, orders,
         approvals, filings,  registrations,  notices or declarations as are set
         forth in  Section  8.1(b)  of the  Gearon  Disclosure  Schedule  or the
         failure  to  obtain  or make  would  not,  in the  reasonable  business
         judgment of ATS, have a material adverse effect on Gearon.

         8.2 Conditions to Obligations of ATS and ATSI. The obligation of ATS to
cause  ATSI to,  and of ATSI to,  effect  the  Merger  shall be  subject  to the
satisfaction of the following conditions,  any or all of which may be waived, in
whole or in part, to the extent permitted by Applicable Law:

                  (a) All agreements, certificates, opinions and other documents
         required to be delivered  pursuant to the  provisions of this Agreement
         shall be reasonably  satisfactory  in form,  scope and substance to ATS
         and its  counsel,  and ATS and its  counsel  shall  have  received  all
         information and copies of all documents, including records of corporate
         proceedings, which they may reasonably request in connection therewith,
         such documents where appropriate to be certified by proper  Authorities
         or corporate officers;

                  (b) Gearon shall have furnished ATS and, at ATS' request,  any
         bank or other  financial  institution  providing  credit to ATS, with a
         favorable opinion, dated the Closing Date, of King &


                                      -27-


<PAGE>

         Spalding,  counsel for Gearon and the Gearon Stockholder,  with respect
         to the matters set forth in Sections  4.1(a),  (b) and (c),  4.6(b) and
         4.21,  Article 6 and with respect to such other  matters  arising after
         the date of this  Agreement  and incident to the Merger,  as ATS or its
         counsel may reasonably request or which may be reasonably  requested by
         any such bank or financial institution or their respective counsel;

                  (c) The  representations  and  warranties  of  Gearon  and the
         Gearon  Stockholder  contained in this  Agreement or otherwise  made in
         writing  by or on  behalf  of it or  any of  them  pursuant  hereto  or
         otherwise made in connection  with the Merger shall be true and correct
         at and as of the Closing  Date with the same force and effect as though
         made on and as of such date  except  those  which speak as of a certain
         date which shall continue to be true and correct as of such date on the
         Closing Date (including  without  limitation giving effect to any later
         obtained  knowledge of Gearon, the Gearon Stockholder or ATS, except as
         otherwise specifically provided herein); each and all of the agreements
         and  conditions  to be  performed  or satisfied by Gearon or the Gearon
         Stockholder  hereunder  at or prior to the Closing Date shall have been
         duly  performed or satisfied in all material  respects;  and Gearon and
         the Gearon  Stockholder shall have furnished ATS with such certificates
         and  other  documents  evidencing  the  truth of such  representations,
         warranties,  covenants  and  agreements  and  the  performance  of such
         agreements or  conditions  as ATS or its counsel shall have  reasonably
         requested;

                  (d) Except to the extent,  if any,  specifically  set forth in
         Section 8.2(d) of the Gearon Disclosure  Schedule,  all authorizations,
         consents,  waivers,  orders or approvals  required by the provisions of
         this Agreement to be obtained from all Persons (other than Authorities)
         prior to the consummation of the Merger,  including without  limitation
         those required in order for Gearon to continue to own all of the Gearon
         Assets  and  continue  to  operate  the Gearon  Business  as  conducted
         immediately prior to the Closing (including without limitation,  at the
         cost and  expense  of Gearon,  all  modifications,  if any,  of Private
         Authorizations,  Leases and Material  Agreements of Gearon set forth in
         Section  8.2(d) of the  Gearon  Disclosure  Schedule)  shall  have been
         obtained, without the imposition,  individually or in the aggregate, of
         any condition or requirement  which could  materially  adversely affect
         Gearon;

                  (e) Between the date of this  Agreement  and the Closing Date,
         there shall not have  occurred and be continuing  any material  adverse
         change  in  Gearon  from  that  reflected  in the  most  recent  Gearon
         Financial  Statements;   as  of  the  Closing  Date,  the  Governmental
         Authorizations with respect to the ownership or operation of the assets
         or the conduct of the business of Gearon shall not have been materially
         and adversely affected by any act, or failure to act, of Gearon;

                  (f) The Gearon  Stockholder and Gearon shall have delivered or
         cause to be delivered to ATS all of the Collateral  Documents and other
         agreements,  documents and instruments  required to be delivered by the
         Gearon Stockholder or Gearon to ATS at or prior to the Closing pursuant
         to the terms of this Agreement;

                  (g) ATS shall have received from its  independent  accountants
         (i) an unqualified report (as to the scope of the audit,  access to the
         books and records and the  cooperation  of management) on the financial
         statements  (consisting  of balance  sheets for each of the fiscal year
         ended  December 31, 1996 and the nine month period ended  September 30,
         1997,  and  statements of operations and cash flow for each of the year
         ended  December 31, 1996 and the nine month period ended  September 30,
         1997) of Gearon which financial  statements shall have been prepared in
         conformity  with GAAP and 

                                      -28-


<PAGE>

         Regulation   S-X  under  the   Securities   Act,  or  (ii)  such  other
         documentation  as shall be reasonably  satisfactory  to ATS  indicating
         that such an unqualified report could be issued if requested by ATS;

                  (h) As of the Closing  Date,  except as otherwise set forth in
         Section 4.6(a) of the Gearon Disclosure Schedule, no Legal Action shall
         be pending before any Authority which might, in the reasonable business
         judgment  of ATS,  based  upon the advice of  counsel,  have a material
         adverse effect on Gearon, it being understood and agreed that a written
         request by any  Authority for  information  with respect to the Merger,
         which  information  could be used in connection with such Legal Action,
         shall  not be  deemed  to be a Legal  Action  pending  before  any such
         Authority;

                  (i) J. Michael  Gearon,  Jr. shall have executed and delivered
         to ATS an  agreement  substantially  in the  form  attached  hereto  as
         Exhibit C and made a part hereof (the "ATS Noncompetition Agreements");

                  (j)  Gearon  shall  have  delivered  to ATS all  use  permits,
         consents or other  Governmental  Authorizations  of and all Leases from
         the United  States  Forest  Service set forth in Section  8.2(j) of the
         Gearon Disclosure Schedule;

                  (k)  The   Environmental   Reports   shall  not  disclose  any
         exception, and no Event or Events shall have occurred subsequent to the
         date hereof, which,  individually or in the aggregate,  would cause the
         representations  and  warranties  of Gearon set forth in  Section  4.20
         (without  regard to  knowledge)  to be  inaccurate or incomplete in any
         material respect;

                  (l) ATS shall have  received,  at its  expense,  a copy of the
         standard ALTA title insurance  policy  insuring  Gearon's fee simple or
         leasehold  interest,  as the case may be, in the land and  improvements
         located at each of the  locations  described  in Section 8.2 (l) of the
         Gearon Disclosure Schedule and the Title Reports shall not disclose any
         exception, and no Event or Events shall have occurred subsequent to the
         date hereof, which,  individually or in the aggregate,  would cause the
         representations  and  warranties  of Gearon  set forth in  Section  4.4
         (without  regard to  knowledge)  to be  inaccurate or incomplete in any
         material respect;

                  (m)  All  Convertible  Securities  and  Option  Securities  of
         Gearon, if any,  outstanding  immediately prior to the Closing shall be
         canceled  and,  from and after the  Closing,  shall no longer be of any
         force or effect;

                  (n) Michael Gearon, Jr., the chief executive officer of Gearon
         and the Gearon Stockholder, shall have executed and delivered to ATS an
         agreement  substantially  in the form attached  hereto as Exhibit D and
         made a part hereof (the "Gearon Employment Agreement");

                  (o) The Gearon  Stockholder  shall have executed and delivered
         to ATS an  agreement  substantially  in the  form  attached  hereto  as
         Exhibit E and made a part hereof (the "Indemnity Escrow Agreement");

                  (p) The Gearon  Stockholder  shall have executed and delivered
         to ATS an  agreement  substantially  in the  form  attached  hereto  as
         Exhibit F and made a part hereof (the "Registration Rights Agreement");

                  (q) The  merger  of  Communications  Towers,  Inc.,  a Georgia
         corporation ("CTI"), with and into ATSI (the "CTI Merger") with ATSI as
         the surviving entity shall have been consummated 


                                      -29-


<PAGE>

         in  accordance  with the GBCC and on terms  and  conditions  reasonably
         satisfactory  to  ATS;  provided,  however,  that  to  the  extent  any
         consideration  is paid by ATS or ATSI  pursuant to the CTI Merger,  the
         Exchange Merger Consideration shall be reduced by an equal amount; and

                  (r) Each of the stockholders of Gearon shall have executed and
         delivered  to ATS an  investment  letter  substantially  in the form of
         Exhibit  G  attached  hereto  and  made  a  part  hereof  (the  "Gearon
         Investment Letters").

         8.3 Conditions to  Obligations  of Gearon.  The obligation of Gearon to
effect  the  Merger  shall  be  subject  to the  satisfaction  of the  following
conditions,  any or all of which  may be  waived,  in  whole or in part,  to the
extent permitted by Applicable Law:

                  (a) All agreements, certificates, opinions and other documents
         required to be delivered  pursuant to the  provisions of this Agreement
         shall be reasonably satisfactory in form, scope and substance to Gearon
         and its  counsel,  and Gearon and its counsel  shall have  received all
         information and copies of all documents, including records of corporate
         proceedings, which they may reasonably request in connection therewith,
         such documents where appropriate to be certified by proper  Authorities
         or corporate officers;

                  (b) ATS shall have furnished Gearon,  with favorable opinions,
         dated the Closing Date, of Sullivan & Worcester  LLP,  counsel for ATS,
         with  respect to the matters set forth in Section 5.1 (a), (b) and (c),
         5.7(b) and 5.16(a) and with respect to such other matters arising after
         the date of this Agreement and incident to the Merger, as Gearon or its
         counsel may reasonably request;

                  (c)  The  representations  and  warranties  of  ATS  and  ATSI
         contained in this  Agreement  or otherwise  made in writing by it or on
         its behalf  pursuant  hereto or otherwise  made in connection  with the
         Merger shall be true and correct at and as of the Closing Date with the
         same  force and  effect as  though  made on and as of such date  except
         those which speak as of a certain date which shall  continue to be true
         and  correct as of such date on the  Closing  Date  (including  without
         limitation giving effect to any later obtained knowledge of Gearon, the
         Gearon  Stockholder or ATS, except as otherwise  specifically  provided
         herein);  each and all of the agreements and conditions to be performed
         or satisfied by ATS and ATSI  hereunder at or prior to the Closing Date
         shall have been duly  performed or satisfied in all material  respects;
         and ATS and ATSI shall have furnished Gearon with such certificates and
         other   documents   evidencing  the  truth  of  such   representations,
         warranties,  covenants  and  agreements  and  the  performance  of such
         agreements  or  conditions  as  Gearon  or  their  counsel  shall  have
         reasonably requested;

                  (d) ATS  shall  have  delivered  or cause to be  delivered  to
         Gearon all of the Collateral Documents and other agreements,  documents
         and  instruments  required to be delivered by ATS to Gearon at or prior
         to the Closing pursuant to the terms of this Agreement;

                  (e) Between the date of this  Agreement  and the Closing Date,
         there shall not have  occurred and be continuing  any material  adverse
         change in ATS from that  reflected  in the most  recent  ATS  Financial
         Statements;

                  (f) As of the Closing  Date,  no Legal Action shall be pending
         before any Authority which might, in the reasonable  business  judgment
         of Gearon,  based upon the advice of counsel,  have a material  adverse
         effect on ATS, it being understood and agreed that a written request by
         any  Authority  

                                      -30-


<PAGE>

         for information with respect to the Merger,  which information could be
         used in connection with such Legal Action,  shall not be deemed to be a
         Legal Action pending before any such Authority;

                  (g)  ATSI  shall  have   executed  and  delivered  the  Gearon
         Employment  Agreement  to  Gearon,  and  pursuant  thereto  the  Gearon
         Stockholder  shall  have been  elected a  director  of ATS and a senior
         executive officer of ATSI;

                  (h) Gearon shall have received evidence of the consummation of
         the ATS Private Placement;

                  (i) ATS shall  have  executed  and  delivered  to  Gearon  the
         Registration Rights Agreement;

                  (j)  The  persons  named  in  Section  8.3(j)  of  the  Gearon
         Disclosure  Schedule shall have been elected to the positions with ATSI
         set forth opposite their respective names, and ATSI shall have executed
         and delivered an employment agreement in a form reasonably satisfactory
         to ATS and Gearon; and

                  (k)  Options  to  purchase  an  aggregate  of  not  more  than
         1,000,000  shares of ATS Class A Common Stock  pursuant to the 1997 ATS
         Stock  Option Plan shall have been granted to employees of Gearon named
         in  Section  8.3(k)  of the  Gearon  Disclosure  Schedule  on terms and
         conditions reasonably satisfactory to Gearon.


                                    ARTICLE 9

                        TERMINATION, AMENDMENT AND WAIVER

         9.1 Termination.  This Agreement may be terminated at any time prior to
the Closing Date:

                  (a) by mutual consent of Gearon and ATS; or

                  (b) by  either  ATS or  Gearon  if any  permanent  injunction,
         decree or judgment by any Authority  preventing the consummation of the
         Merger shall have become final and nonappealable; or

                  (c) by Gearon in the event (i)  neither  Gearon nor the Gearon
         Stockholder are in material breach of this Agreement and none of its of
         their  representations  or warranties shall have become and continue to
         be untrue in any manner  that would  cause the  condition  set forth in
         Section 8.2(c) not to be satisfied,  and (ii) either (A) the Merger has
         not been  consummated  prior to the Termination  Date, or (B) ATS is in
         material  breach of this  Agreement  or any of its  representations  or
         warranties  shall have  become and  continue to be untrue in any manner
         that would cause the  conditions  set forth in Section 8.3(c) not to be
         satisfied,  and such a breach or untruth  exists and is not  capable of
         being cured by and will prevent or delay  consummation of the Merger by
         or beyond the Termination Date; or

                  (d) by ATS in the event (i) ATS is not in  material  breach of
         this Agreement and none of its representations or warranties shall have
         become and  continue  to be untrue in any manner  that would  cause the
         condition  set forth in Section  8.3(c) not to be  satisfied,  and (ii)
         either (A) the Merger has not been consummated prior to the Termination
         Date, or (B) Gearon or the Gearon Stockholder

                                      -31-


<PAGE>

         are in material  breach of this  Agreement or any of Gearon's or any of
         the  Gearon  Stockholder's  representations  or  warranties  shall have
         become and  continue  to be untrue in any manner  that would  cause the
         conditions set forth in Section 8.2(c) not to be satisfied,  and such a
         breach or untruth  exists and is not capable of being cured by and will
         prevent  or  delay   consummation  of  the  Merger  by  or  beyond  the
         Termination Date.

         The term "Termination  Date" shall mean February 28, 1998 or such other
date as the parties may, from time to time, mutually agree.

         The right of ATS or Gearon to terminate this Agreement pursuant to this
Section shall remain  operative  and in full force and effect  regardless of any
investigation made by or on behalf of any party, any Person controlling any such
party or any of their respective  Representatives  whether prior to or after the
execution of this Agreement.

         9.2 Effect of Termination.

         (a)   Except  as   provided   in   Sections   7.1  (with   respect   to
confidentiality), 7.3 and 11.2 and this Section, in the event of the termination
of this Agreement  pursuant to Section 9.1, or in the event the Merger shall not
have been  consummated  prior to the end of  business on the  Termination  Date,
except as otherwise  provided in Section 9.2(b),  this Agreement shall forthwith
become void,  there shall be no  liability  on the part of any party,  or any of
their  respective  shareholders,  officers  or  directors,  to the other and all
rights and obligations of any party shall cease;  provided,  however,  that such
termination shall not relieve any party from liability for any misrepresentation
or breach of any of its  warranties,  covenants or agreements  set forth in this
Agreement.

         (b) In the event this Agreement is terminated by Gearon pursuant to the
provisions  of Section  9.1(c),  then Gearon  shall be  entitled  to  liquidated
damages  in an  amount  equal to (i) if such  termination  occurs  on or  before
January 2, 1998,  $5,000,000,  and (ii) if such termination occurs after January
2, 1998,  $10,000,000;  the parties agree that such amount shall constitute full
payment for any and all damages  suffered by Gearon by reason of ATS' failure to
consummate the Merger. ATS and Gearon agree in advance that actual damages would
be  difficult  to  ascertain  and that  such  liquidated  damages  is a fair and
equitable amount to reimburse  Gearon for damages  sustained due to ATS' failure
to  consummate  the Merger for the  above-stated  reasons.  Notwithstanding  the
foregoing,  Gearon shall have the right to seek specific performance pursuant to
the provisions of Section 11.4.

         (c)  In  the  event  this  Agreement  is  terminated  pursuant  to  the
provisions of Section  9.1(a),  9.1(b) or 9.1(d),  except as provided in Section
9.2(a), none of the parties shall have any further rights or remedies.


                                   ARTICLE 10

                                 INDEMNIFICATION

         10.1  Survival.  The  representations  and  warranties  of the  parties
contained in or made pursuant to this Agreement or any Collateral Document shall
survive the Closing and shall remain  operative and in full force and effect for
a period of eighteen (18) months after the Closing Date, except that in the case
of matters of a nature  referred to in Sections 4.1, 4.10,  4.11, 4.20 and 4.21,
Sections  5.1,  5.9,  5.11 and 5.16 and Article 6 which shall survive and remain
operative  and  in  full  force  and  effect  for  the  applicable   statute  of
limitations,  
                                      -32-


<PAGE>


regardless of any  investigation  or statement as to the results thereof made by
or on behalf of any party hereto.  The  covenants and  agreements of the parties
contained in or made pursuant to this Agreement or any Collateral Document shall
survive the Closing  (unless any such covenant or agreement by its express terms
in this  Agreement  does not so survive) and shall remain  operative and in full
force and  effect for the  statute  of  limitations  applicable  to  contractual
obligations.  The term "Indemnity  Period" shall mean the applicable period with
respect to which a representation,  warranty, covenant or agreement survives the
Closing as provided in this Section.  No claim for  indemnification,  other than
with respect to fraud or intentional  and willful  breach or  misrepresentation,
may be asserted  after the expiration of the Indemnity  Period.  Notwithstanding
anything  herein to the contrary,  any  representation,  warranty,  covenant and
agreement  which  arises and is the  subject  of a Claim  which is  asserted  in
writing prior to the expiration of the applicable Indemnity Period shall survive
with respect to such Claim or any dispute with respect  thereto  until the final
resolution thereof.

         10.2 Indemnification.

         (a) The  Gearon  Stockholder  agrees  that on and after the  Closing he
shall   indemnify  and  hold   harmless  ATS  and  ATSI  and  their   respective
stockholders,  directors, officers, employees and representatives (collectively,
the "ATS  Indemnified  Parties")  from and against any and all damages,  claims,
losses,  expenses,  costs,  obligations,   and  liabilities  including,  without
limiting  the  generality  of the  foregoing,  liabilities  for  all  reasonable
attorneys',  accountants'  and experts'  fees and expenses  incurred,  including
those incurred to enforce the terms of this Agreement or any Collateral Document
(collectively,  "Loss and Expense"),  suffered by the ATS Indemnified Parties by
reason of, or arising out of any breach of  representation  or warranty  made by
Gearon or the Gearon  Stockholder  pursuant to this  Agreement or any Collateral
Document  or any  failure  by Gearon or the  Gearon  Stockholder  to  perform or
fulfill any of its or any of their  covenants  or  agreements  set forth in this
Agreement or any Collateral Document.

         (b) ATS and ATSI,  jointly and  severally,  agree that on and after the
Closing they will  indemnify the Gearon  Stockholder  and hold him harmless from
and  against  all Loss and  Expense  suffered  by any of them by  reason  of, or
arising out of :

                  (i) any breach of  representation  or warranty  made by ATS or
         ATSI  pursuant  to this  Agreement  or any  Collateral  Document or any
         failure by ATS or ATSI to perform or fulfill  any of its  covenants  or
         agreements set forth in this Agreement or any Collateral Document; or

                  (ii) any  Legal  Action  or other  Claim  by any  third  party
         relating  to ATS or ATSI or the  ownership  or  operations  of Gearon's
         business and properties  subsequent to the Closing,  including  without
         limitation any and all obligations and liabilities  under  Governmental
         Authorizations,  Private  Authorizations,  Leases, Material Agreements,
         Employment Arrangements, Plans, Benefit
         Arrangements and Contractual Obligations.

         10.3     Limitation of Liability.

         (a)  Notwithstanding the provisions of Section 10.2, after the Closing,
except as otherwise  provided in Section 10.6, the ATS Indemnified  Parties,  on
the one hand,  and Gearon,  on the other hand,  shall be entitled to recover its
Loss and  Expense in  respect of any Claim only in the event that the  aggregate
Loss and Expense for all Claims exceeds,  in the aggregate,  $100,000,  in which
event the  indemnified  party  shall be  entitled  to recover  all such Loss and
Expense (including without limitation such $100,000).

 

                                      -33-


<PAGE>

         (b) In the case any event shall occur which would otherwise entitle any
party to assert a claim for indemnification hereunder, no Loss and Expense shall
be deemed to have been  sustained  by such party to the  extent of any  proceeds
received by such party from any insurance policies with respect thereto.

         10.4 Notice of Claims.  If an  indemnified  party  believes that it has
suffered or incurred  any Loss and  Expense,  it shall  notify the  indemnifying
party  promptly in writing,  and in any event  within the  applicable  Indemnity
Period  specified in Section 10.1,  describing  such Loss and Expense,  all with
reasonable  particularity  and  containing a reference to the provisions of this
Agreement in respect of which such Loss and Expense shall have occurred.  If any
Legal Action is instituted by a third party with respect to which an indemnified
party  intends to claim any  liability or expense as Loss and Expense under this
Article,  such indemnified party shall promptly notify the indemnifying party of
such Legal Action, but the failure to so notify the indemnifying party shall not
relieve such indemnifying party of its obligations under this Article, except to
the extent such failure to notify prejudices such  indemnifying  party's ability
to defend against such Claim.

         10.5 Defense of Third Party Claims.  The indemnifying  party shall have
the right to  conduct  and  control,  through  counsel  of their  own  choosing,
reasonably  acceptable to the indemnified party, any third party Legal Action or
other Claim, but the indemnified party may, at its election,  participate in the
defense  thereof at its sole cost and expense;  provided,  however,  that if the
indemnifying  party shall fail to defend any such Legal  Action or other  Claim,
then the indemnified party may defend, through counsel of its own choosing, such
Legal Action or other Claim, and (so long as it gives the indemnifying  party at
least fifteen (15) days' notice of the terms of the proposed  settlement thereof
and permits the indemnifying party to then undertake the defense thereof) settle
such Legal Action or other Claim and to recover the amount of such settlement or
of any  judgment and the  reasonable  costs and  expenses of such  defense.  The
indemnifying party shall not compromise or settle any such Legal Action or other
Claim without the prior written consent of the indemnified  party, which consent
shall not  unreasonably  be withheld,  delayed or  conditioned  if the terms and
conditions of such compromise or settlement  proposed by the indemnifying  party
and agreed to in writing by the  claimant  in such Legal  Action or other  Claim
(the "Settlement  Proposal") (a) include a full release of the indemnified party
from the Legal  Action or other  Claim  which is the  subject of the  Settlement
Proposal,  and (b) if the indemnified party is an ATS Indemnified  Party, do not
include any term or condition  which would  restrict in any material  manner the
continued  ownership or  operations  of the Gearon  Assets or the conduct of the
Gearon  Business  in  substantially  the manner  then being  theretofore  owned,
operated and conducted by ATS or Gearon (or any successor or assign).  No matter
whether an indemnifying party defends or prosecutes any third party Legal Action
or Claim,  the  indemnified  and  indemnifying  parties  shall  cooperate in the
defense or prosecution  thereof.  Such  cooperation  shall include access during
normal  business  hours  afforded to the  indemnifying  party to, and reasonable
retention  by the  indemnified  party  of,  records  and  information  which are
reasonably  relevant  to such  third  party  Legal  Action or Claim,  and making
employees  available  on a  mutually  convenient  basis  to  provide  additional
information  and  explanation  of  any  material  provided  hereunder,  and  the
indemnifying  party shall reimburse the indemnified party for all its reasonable
out-of-pocket expenses in connection therewith.

         10.6  Exclusive  Remedy.  Except  for  fraud,  willful  or  intentional
misrepresentation  or willful or  intentional  breach of  warranty,  covenant or
agreement or as otherwise provided in Section 11.4, the indemnification provided
in this Article shall be the sole and exclusive post-Closing remedy available to
any party against the other party for any Claim under this Agreement.



                                      -34-

<PAGE>



                                   ARTICLE 11

                               GENERAL PROVISIONS


         11.1 Waivers; Amendments. Changes in or additions to this Agreement may
be made,  or compli  ance  with any  term,  covenant,  agreement,  condition  or
provision  set forth herein may be omitted or waived  (either  generally or in a
particular  instance and either  retroactively or prospectively)  with, but only
with,  the  consent in writing of the  parties  hereto.  No delay on the part of
either  party at any time or times in the  exercise of any right or remedy shall
operate as a waiver thereof. Any consent may be given subject to satisfaction of
conditions  stated therein.  The failure to insist upon the strict provisions of
any  covenant,  term,  condition  or other  provision  of this  Agreement  or to
exercise  any right or remedy  thereunder  shall not  constitute a waiver of any
such  covenant,  term,  condition  or other  provision  thereof  or  default  in
connection  therewith.  The waiver of any  covenant,  term,  condition  or other
provision thereof or default thereunder shall not affect or alter this Agreement
in any other  respect,  and each and every  covenant,  term,  condition or other
provision of this  Agreement  shall,  in such event,  continue in full force and
effect,  except as so waived,  and shall be operative  with respect to any other
then existing or subsequent default in connection therewith.

         11.2 Fees, Expenses and Other Payments.  All  Hart-Scott-Rodino  filing
fees  shall be borne  equally by Gearon  and ATS,  and all costs of  preliminary
title reports to a date  reasonably  proximate to the Closing Date and all costs
of environmental studies shall be borne by ATS. All costs and expenses, incurred
in connection  with any transfer  taxes,  sales taxes,  recording or documentary
taxes,  stamps or other charges levied by any Authority in connection  with this
Agreement and the consummation of the Merger shall be borne by ATS and all other
costs  and  expenses   incurred  in  connection  with  this  Agreement  and  the
consummation of the Merger,  including without limitation fees and disbursements
of counsel,  financial advisors and accountants  incurred by the parties hereto,
shall be borne solely and  entirely by the party which has  incurred  such costs
and expenses.

         11.3  Notices.  All  notices  and  other  communications  which  by any
provision of this Agreement are required or permitted to be given shall be given
in writing and shall be deemed to have been  delivered  (a) three (3) days after
being mailed by first-class or express mail,  postage prepaid,  (b) the next day
when sent overnight by recognized  courier service,  (c) upon  confirmation when
sent by telex, telegram, telecopy or other form of rapid transmission, confirmed
by mailing (by first class or express mail,  postage  prepaid,  or by recognized
courier  service) written  confirmation at  substantially  the same time as such
rapid  transmission,  or (d) upon  delivery  when  personally  delivered  to the
receiving party (which if other than an individual  shall be an officer or other
responsible party of the receiving party).  All such notices and  communications
shall be mailed, sent or delivered as follows:

         (a)      If to ATS:

                  116 Huntington Avenue
                  Boston, Massachusetts 02116
                  Attention:   Joseph L. Winn, Chief Financial Officer
                  Telecopier No.:  (617) 375-7575


                                      -35-


<PAGE>



                  with a copy to:

                  Sullivan & Worcester LLP
                  One Post Office Square
                  Boston, Massachusetts 02109
                  Attention:  Norman A. Bikales, Esq.
                  Telecopier No.:  (617) 338-2880

         (b)      If to Gearon or the Gearon Stockholder:

                  1760 The Exchange, N.W.
                  Suite 200
                  Atlanta, Georgia 30339
                  Attention: J. Michael Gearon, Jr., President
                  Telecopier No.:   (770) 952-4999

                  with a copy to:

                  King & Spalding
                  191 Peachtree Street
                  Atlanta, Georgia  30303-1763
                  Attention: William H. Hess, Esq.
                  Telecopier No.:  (404) 572-5100

or to such other person(s),  telex or facsimile  number(s) or address(es) as the
party to receive any such communication or notice may have designated by written
notice to the other party.

         11.4  Specific  Performance;  Other  Rights  and  Remedies.  Each party
recognizes and agrees that in the event the other party should refuse to perform
any of its  obligations  under this  Agreement or any Collateral  Document,  the
remedy at law would be inadequate and agrees that for breach of such provisions,
each party shall,  in addition to such other  remedies as may be available to it
at law or in equity or as provided in Section  9.2(b) or Article 10, be entitled
to  injunctive  relief  and to  enforce  its  rights by an action  for  specific
performance to the extent  permitted by Applicable Law. Each party hereby waives
any  requirement  for  security  or the  posting of any bond or other  surety in
connection  with any temporary or permanent  award of  injunctive,  mandatory or
other  equitable  relief.   Nothing  herein  contained  shall  be  construed  as
prohibiting each party from pursuing any other remedies available to it pursuant
to the  provisions  of this  Agreement  or  Applicable  Law for such  breach  or
threatened  breach,  including  without  limitation  the  recovery  of  damages,
including, to the extent awarded in any Legal Action,  punitive,  incidental and
consequential  damages  (including  without limitation damages for diminution in
value and loss of anticipated profits) or any other measure of damages permitted
by Applicable Law.

         11.5 Severability.  If any term or provision of this Agreement shall be
held or deemed  to be, or shall in fact be,  invalid,  inoperative,  illegal  or
unenforceable  as  applied  to  any  particular  case  in  any  jurisdiction  or
jurisdictions,  or in  all  jurisdictions  or  in  all  cases,  because  of  the
conflicting of any provision with any  constitution or statute or rule of public
policy or for any other reason,  such circumstance  shall not have the effect of
rendering the provision or provisions in question invalid, inoperative,  illegal
or unenforceable in any other  jurisdiction or in any other case or circumstance
or of rendering any other  provision or  provisions  herein  contained  invalid,
inoperative,  illegal or  unenforceable to the extent that such other 

                                      -36-


<PAGE>

provisions  are not  themselves  actually  in conflict  with such  constitution,
statute or rule of public  policy,  but this  Agreement  shall be  reformed  and
construed  in any such  jurisdiction  or case as if such  invalid,  inoperative,
illegal or  unenforceable  provision  had never been  contained  herein and such
provision  reformed so that it would be valid,  operative and enforceable to the
maximum extent permitted in such  jurisdiction or in such case.  Notwithstanding
the foregoing,  in the event of any such determination the effect of which is to
affect  materially and adversely any party,  the parties shall negotiate in good
faith to modify  this  Agreement  so as to  effect  the  original  intent of the
parties as closely as possible to the fullest extent permitted by Applicable Law
in an  acceptable  manner to the end that the  Transactions  are  fulfilled  and
consummated to the maximum extent possible.

         11.6   Counterparts.   This   Agreement  may  be  executed  in  several
counterparts,  each of  which  shall be  deemed  an  original,  but all of which
together shall constitute one and the same  instrument,  binding upon all of the
parties. In pleading or proving any provision of this Agreement, it shall not be
necessary to produce more than one of such counterparts.

         11.7 Section Headings. The headings contained in this Agreement are for
reference  purposes  only  and  shall  not in any  way  affect  the  meaning  or
interpretation of this Agreement.

         11.8  Governing  Law. The validity,  interpretation,  construction  and
performance of this Agreement  shall be governed by, and construed in accordance
with,  the  applicable  laws of the United States of America and the laws of the
State of New York  applicable to contracts made and performed in such State and,
in any event,  without giving effect to any choice or conflict of laws provision
or rule that would cause the  application  of domestic  substantive  laws of any
other jurisdiction.

         11.9 Further Acts. Each party agrees that at any time, and from time to
time, before and after the consummation of the transactions contemplated by this
Agreement,  it  will do all  such  things  and  execute  and  deliver  all  such
Collateral  Documents  and other  assurances,  as any other party or its counsel
reasonably  deems  necessary  or  desirable  in order to carry out the terms and
conditions of this  Agreement  and the  transactions  contemplated  hereby or to
facilitate  the enjoyment of any of the rights  created  hereby or to be created
hereunder.

         11.10  Entire  Agreement.  This  Agreement  (together  with the  Gearon
Disclosure  Schedule,  the Exhibits and the other Collateral Documents delivered
or to be delivered in connection  herewith)  constitutes the entire agreement of
the parties with respect to the subject  matter hereof and  supersedes all prior
agreements,   arrangements,   covenants,  promises,  conditions,   undertakings,
inducements, representations, warranties and negotiations, expressed or implied,
oral or written, between the parties, with respect to the subject matter hereof.
Each of the  parties  is a  sophisticated  legal  entity  that  was  advised  by
experienced  counsel and, to the extent it deemed  necessary,  other advisors in
connection with this Agreement. Each of the parties hereby acknowledges that (a)
none of the parties has relied or will rely in respect of this  Agreement or the
transactions   contemplated   hereby  upon  any  document  or  written  or  oral
information  previously furnished to or discovered by it or its representatives,
other than this  Agreement  (or such of the  foregoing  as are  delivered at the
Closing,  (b) there are no covenants or  agreements by or on behalf of any party
or any  of  its  respective  Affiliates  or  representatives  other  than  those
expressly set forth in this Agreement and the Collateral Documents,  and (c) the
parties'  respective  rights and obligations  with respect to this Agreement and
the events giving rise thereto will be solely as set forth in this Agreement and
the Collateral Documents. WITHOUT LIMITING THE GENERALITY OF THE FOREGOING, EACH
PARTY  HERETO  AGREES  THAT,  EXCEPT  FOR  THE  REPRESENTATIONS  AND  WARRANTIES
CONTAINED IN THIS AGREEMENT, NONE OF THE PARTIES MAKES ANY OTHER REPRESENTATIONS
OR WARRANTIES,

                                      -37-


<PAGE>


AND EACH HEREBY DISCLAIMS ANY OTHER REPRESENTATIONS OR WARRANTIES MADE BY ITSELF
OR ANY OF ITS  OFFICERS,  DIRECTORS,  EMPLOYEES,  AGENTS,  FINANCIAL  AND  LEGAL
ADVISORS OR OTHER REPRESENTATIVES, WITH RESPECT TO THE EXECUTION AND DELIVERY OF
THIS AGREEMENT OR THE  TRANSACTIONS  CONTEMPLATED  HEREBY,  NOTWITHSTANDING  THE
DELIVERY  OR  DISCLOSURE  TO THE  OTHER OR THE  OTHER'S  REPRESENTATIVES  OF ANY
DOCUMENTATION  OR  OTHER  INFORMATION  WITH  RESPECT  TO ANY  ONE OR MORE OF THE
FOREGOING.

         11.11  Assignment.  This Agreement shall not be assignable by any party
and any such  assignment  shall be null and void,  except that it shall inure to
the benefit of and by binding  upon any  successor  to any party by operation of
law,  including by way of merger,  consolidation or sale of all or substantially
all of its assets,  and ATS may assign its rights and remedies  hereunder to any
bank or other financial institution which has loaned funds or otherwise extended
credit to it.

         11.12  Parties in Interest.  This  Agreement  shall be binding upon and
inure  solely to the  benefit of each  party,  and  nothing  in this  Agreement,
express or implied,  is  intended to or shall  confer upon any Person any right,
benefit or remedy of any nature whatsoever under or by reason of this Agreement,
except as otherwise provided in Section 11.11.

         11.13  Mutual  Drafting.  This  Agreement  is the  result  of the joint
efforts of Gearon and ATS,  and each  provision  hereof has been  subject to the
mutual consultation, negotiation and agreement of the parties and there shall be
no  construction  against any party  based on any  presumption  of that  party's
involvement in the drafting thereof.

         11.14 Due Diligence.  Each of the parties shall have the right,  during
the period  between the date hereof and 11:59 p.m.,  Eastern  Standard  Time, on
December 1, 1997 (the "Due Diligence  Period") (a) to continue their  respective
due  diligence  investigation  of the other  party and (b) to give notice to the
other party that it is  terminating  this  Agreement  because such due diligence
investigation  has  indicated  that (i) a material  adverse  change in the other
party has occurred of which the terminating  party was unaware as of the date of
this Agreement,  (ii) a material breach of the representations and warranties of
the other party has  occurred of which the  terminating  party was unaware as of
the date of this Agreement and the terminating  party  reasonably  believes that
such breach is not capable of being cured by the  Termination  Date, or (iii) in
the  case  of ATS  and  ATSI,  as the  terminating  party,  ATS  has  reasonably
determined  that the  Operating  Cash  Flow of  Gearon  for the  quarter  ending
December  31,  1997 set forth in the  financial  projection  included in Section
11.14 of the Gearon  Disclosure  Schedule is not likely to be  achieved  and the
amount of such negative  variance is reasonably likely to exceed 5 percent (5%);
provided,  however,  that  such  negative  variance  shall  not  give  rise to a
termination  right  pursuant to the  provisions of this Section if the amount of
such variance is reasonably likely to be recouped in all material respects on or
prior to March 31, 1998. In the event of any such  termination,  the terminating
party shall give the other party written  notice thereof prior to the expiration
of the Due Diligence Period and, thereafter, the parties shall negotiate in good
faith to  determine  the  validity  of the grounds of such  termination  and, if
necessary, an adjustment in the Merger Consideration.  If the parties are unable
within ten (10)  business  days  following  the  giving of any such  termination
notice  to  resolve  their  differences,   either  party  may  termination  this
Agreement,  whereupon it shall  become void,  there shall be no liability on the
part  of any  party,  or any  of  their  respective  shareholders,  officers  or
directors, to the other and all rights and obligations of any party shall cease;
provided,  however,  that such  termination  shall not  relieve  any party  from
liability  for  any  misrepresentation  or  breach  of any  of  its  warranties,
covenants or agreements set forth in this Agreement.

                                      -38-

<PAGE>


                      [SIGNATURES APPEAR ON FOLLOWING PAGE]







                                      -39-


<PAGE>



         IN WITNESS WHEREOF,  the parties have executed or caused this Agreement
to be executed by their respective  officers thereunto duly authorized as of the
date first written above.

                                   American Tower Systems Corporation


                                   By: /s/ Joseph L. Winn
                                      Name: Joseph L. Winn
                                     Title: Chief Financial Officer


                                   American Tower Systems, Inc.


                                   By: /s/ Joseph L. Winn
                                      Name: Joseph L. Winn
                                     Title: Chief Financial Officer

                                   Gearon & Co., Inc.


                                   By: /s/ J. Michael Gearon, Jr.
                                      Name: J. Michael Gearon, Jr.
                                     Title: President


                                   Gearon Stockholder


                                   /s/ J. Michael Gearon, Jr.
                                   J. Michael Gearon, Jr.



                                      -40-


<PAGE>




                                                                      APPENDIX A

                                   DEFINITIONS

         adverse,  adversely, when used alone or in conjunction with other terms
(including  without  limitation  "affect," "change" and "effect") shall mean any
Event which is reasonably  likely,  in the reasonable  business  judgment of the
relevant  party,  to be  expected  to  (a)  adversely  affect  the  validity  or
enforceability  of this  Agreement  or the  likelihood  of  consummation  of the
Merger, or (b) adversely affect the business, operations, management, properties
or prospects,  or the condition,  financial or other, or results of operation of
the Gearon Business or the business of ATS or ATSI, as applicable, or (c) impair
such  party's  ability  to  fulfill  its  obligations  under  the  terms of this
Agreement,  or (d) adversely  affect the  aggregate  rights and remedies of such
party under this Agreement.  Notwithstanding the foregoing, and anything in this
Agreement to the contrary  notwithstanding,  any Event  generally  affecting the
economy or the tower  communications  business shall not be deemed to constitute
such a change, affect or effect.

         Affiliate,  Affiliated shall mean, with respect to any Person,  (a) any
other Person at the time  directly or indirectly  controlling,  controlled by or
under direct or indirect  common control with such Person,  (b) any other Person
of which such Person at the time owns, or has the right to acquire,  directly or
indirectly,  five  percent  (5%) or more of any  class of the  capital  stock or
beneficial  interest,  (c) any other Person  which at the time owns,  or has the
right to acquire, directly or indirectly, five percent (5%) or more of any class
of the capital  stock or beneficial  interest of such Person,  (d) any executive
officer or director of such Person,  (e) with respect to any partnership,  joint
venture or similar Entity,  any general partner thereof,  and (f) when used with
respect  to an  individual,  shall  include  any  member  of  such  individual's
immediate family or a family trust.

         Agreement shall mean this Agreement as originally in effect, including,
unless the context otherwise specifically requires,  this Appendix A, the Gearon
Disclosure Schedule,  the ATS Information Statement and all exhibits hereto, and
as any of the same may from time to time be supplemented,  amended,  modified or
restated in the manner herein or therein provided.

         Alternative  Transaction  shall have the meaning given to it in Section
7.5.

         Applicable Law shall mean any Law of any Authority, whether domestic or
foreign,  including  without  limitation  the  FCA  and all  federal  and  state
securities and  Environmental  Laws, to which a Person is subject or by which it
or any of its business or operations is subject or any of its property or assets
is bound.

         ATS shall have the meaning given to it in the Preamble.

         ATS Class A Common Stock shall have the meaning  given to it in Section
3.1(b).

         ATS Financial  Statements shall have the meaning given to it in Section
5.2

         ATS  Indemnified  Parties shall have the meaning given to it in Section
10.2(a)

         ATS Information Statement shall mean the Information  Statement,  draft
dated  November  17,  1997,  describing  the  business of ATS and certain  other
matters heretofore delivered by ATS to Gearon.


                                       A-1


<PAGE>



         ATS'  knowledge  (or words of  similar  import)  shall  mean the actual
knowledge of any director or executive officer of ATS or ATSI, as such knowledge
exists on the date of this Agreement, after reasonable review of appropriate ATS
and ATSI  records  and after  reasonable  inquiry  of  appropriate  ATS and ATSI
employees.

         ATS  Noncompetition  Agreements  shall have the meaning  given to it in
Section 8.2(i).

         ATS Private Placement shall mean the issue and sale by ATS of shares of
ATS Common Stock to certain officers and directors of ATS (or their  Affiliates)
for an aggregate  consideration of not less than $75.0 million, all as described
in the ATS Information Statement.

         ATSI shall have the meaning given to it in the Preamble.

         Authority shall mean any governmental or quasi-governmental  authority,
whether  administrative,  executive,  judicial,  legislative  or  other,  or any
combination   thereof,   including  without   limitation  any  federal,   state,
territorial,   county,   municipal  or  other   government  or  governmental  or
quasi-governmental agency, arbitrator,  authority,  board, body, branch, bureau,
or comparable  agency or Entity,  commission,  corporation,  court,  department,
instrumentality,  mediator, panel, system or other political unit or subdivision
or other Entity of any of the foregoing,  whether domestic or foreign, including
without limitation the FCC.

         Benefit Arrangement shall mean any material benefit arrangement that is
not a Plan,  including  (a)  any  employment  or  consulting  agreement  (b) any
arrangement providing for insurance coverage or workers' compensation  benefits,
(c) any  incentive  bonus or deferred  bonus  arrangement,  (d) any  arrangement
providing termination  allowance,  severance or similar benefits, (e) any equity
compensation plan, (f) any deferred  compensation plan, and (g) any compensation
policy and  practice,  but only to the  extent  that it covers or relates to any
officer, employee or other Person involved in the ownership and operation of the
assets of Gearon or the conduct of the business of Gearon.

         Cash  Consideration  shall  have the  meaning  given  to it in  Section
3.1(b).

         Certificate shall have the meaning given to it in Section 3.1(b).

         Claims shall mean any and all debts, liabilities,  obligations, losses,
damages,  deficiencies,  assessments  and  penalties,  together  with all  Legal
Actions, pending or threatened, claims and judgments of whatever kind and nature
relating  thereto,  and all fees, costs,  expenses and disbursements  (including
without  limitation  reasonable  attorneys'  and  other  legal  fees,  costs and
expenses) relating to any of the foregoing.

         Closing shall have the meaning given to it in Section 2.2.

         Closing Date shall have the meaning given to it in Section 2.2.

         COBRA shall mean the Consolidated Omnibus Budget  Reconciliation Act of
1985,  as  amended,  as set  forth  in  Section  4980B of the Code and Part 6 of
Subtitle B of Title I of ERISA.

         Code shall mean the Internal  Revenue  Code of 1986,  and the rules and
regulations  thereunder,  all as from time to time in effect,  or any  successor
law,  rules or  regulations,  and any  reference to any  statutory or regulatory
provision  shall be deemed  to be a  reference  to any  successor  statutory  or
regulatory provision.


                                       A-2


<PAGE>



         Collateral Documents shall mean the Indemnity Escrow Agreement, the ATS
Noncompetition  Agreements,  the Gearon Employment Agreement,  the Gearon Notes,
the Gearon Security Agreement, the Gearon Investment Letters, the Certificate of
Merger, the Articles of Merger, and any other agreement, certificate,  contract,
instrument,  notice,  opinion  or  other  document  delivered  pursuant  to  the
provisions of this Agreement or any Collateral Document.

         Confidential  Information shall have the meaning given to it in Section
7.1(a).

         Contract, Contractual Obligation shall mean any agreement, arrangement,
commitment,  contract, covenant,  indemnity,  undertaking or other obligation or
liability  which  involves the ownership or operation of the assets of Gearon or
the conduct of the business of Gearon.

         Control (including the terms  "controlled,"  "controlled by" and "under
common control with") means the possession, directly or indirectly or as trustee
or executor,  of the power to direct or cause the direction of the management or
policies of a Person,  or the disposition of such Person's assets or properties,
whether through the ownership of stock, equity or other ownership,  by contract,
arrangement or understanding,  or as trustee or executor,  by contract or credit
arrangement or otherwise.

         Convertible Securities shall mean any evidences of indebtedness, shares
of capital  stock  (other than  common  stock) or other  securities  directly or
indirectly  convertible into or exchangeable for shares of common stock, whether
or not the right to convert or exchange thereunder is immediately exercisable or
is conditioned  upon the passage of time, the  occurrence or  non-occurrence  or
existence or non-existence of some other Event, or both.

         CTI shall have the meaning given to it in Section 8.2(q).

         CTI Merger shall have the meaning given to it in Section 8.2(q).

         GBCC shall have the meaning given to it in Section 2.1.

         DCL shall have the meaning given to it in Section 2.1.

         Distribution   shall  mean,  with  respect  to  any  Person,   (a)  the
declaration or payment of any dividend (except dividends payable in common stock
of such Person) on or in respect of any shares of any class of capital  stock of
such Person or any shares of capital stock of any  Subsidiary  owned by a Person
other than the Company or a Subsidiary,  (b) the  purchase,  redemption or other
retirement  of any  shares of any class of capital  stock of such  Person or any
shares of capital stock of any Subsidiary of such Person owned by a Person other
than such Person or a Subsidiary of such Person,  and (c) any other distribution
on or in respect of any shares of any class of capital  stock of such  Person or
any shares of capital  stock of any  Subsidiary of such Person owned by a Person
other than such Person or a Subsidiary of such Person.

         Due  Diligence  Period  shall have the  meaning  given to it in Section
11.14.

         Effective Time shall have the meaning given to it in Section 2.3.

         Employment   Arrangement  shall  mean,  with  respect  to  Gearon,  any
employment,  consulting,  retainer,  severance or similar  contract,  agreement,
plan,  arrangement or policy (exclusive of any which is terminable within thirty
(30) days  without  liability,  penalty  or payment of any kind by Gearon or any
Affiliate), or

                                       A-3


<PAGE>



providing for severance, termination payments, insurance coverage (including any
self-insured  arrangements),  workers compensation,  disability benefits,  life,
health, medical, dental or hospitalization  benefits,  supplemental unemployment
benefits, vacation or sick leave benefits, pension or retirement benefits or for
deferred compensation, profit-sharing, bonuses, stock options, stock purchase or
appreciation rights or other forms of incentive  compensation or post-retirement
insurance,  compensation or post-retirement insurance, compensation or benefits,
or any collective bargaining or other labor agreement, whether or not any of the
foregoing is subject to the provisions of ERISA,  but only to the extent that it
covers or relates to any  officer,  employee  or other  Person  involved  in the
ownership  or  operation  of the  Gearon  Assets or the  conduct  of the  Gearon
Business.

         Encumber  shall  mean  to  suffer,  accept,  agree  to  or  permit  the
imposition of a Lien.

         Entity shall mean any corporation,  firm, unincorporated  organization,
association,  partnership,  limited  liability  company,  trust  (inter vivos or
testamentary),  estate of a deceased, insane or incompetent individual, business
trust,  joint stock  company,  joint  venture or other  organization,  entity or
business,  whether acting in an individual,  fiduciary or other capacity, or any
Authority.

         Environmental Law shall mean any Law relating to or otherwise  imposing
liability or  standards of conduct  concerning  pollution or  protection  of the
environment,   including   without   limitation   Laws  relating  to  emissions,
discharges,  releases or  threatened  releases of  Hazardous  Materials or other
chemicals or  industrial  pollutants,  substances,  materials or wastes into the
environment (including,  without limitation,  ambient air, surface water, ground
water,  mining or reclamation or mined land, land surface or subsurface  strata)
or otherwise relating to the manufacture,  processing, generation, distribution,
use, treatment, storage, disposal, cleanup, transport or handling of pollutants,
contaminants,  chemicals or industrial, toxic or hazardous substances, materials
or wastes. Environmental Laws shall include without limitation the Comprehensive
Environmental  Response,  Compensation and Liability Act (42 U.S.C. Section 6901
et seq.), the Hazardous Material  Transportation Act (49 U.S.C.  Section 1801 et
seq.),  the Resource  Conservation  and Recovery Act (42 U.S.C.  Section 6901 et
seq.), the Federal Water Pollution Control Act (33 U.S.C. Section 1251 et seq.),
the Clean Air Act (42 U.S.C. Section 7401 et seq.), the Toxic Substances Control
Act (15 U.S.C. Section 2601 et seq.), the Occupational Safety and Health Act (29
U.S.C.  Section 651 et seq.), the Federal Insecticide  Fungicide and Rodenticide
Act (7  U.S.C.  Section  136 et  seq.),  and  the  Surface  Mining  Control  and
Reclamation  Act of 1977 (30 U.S.C.  Section  1201 et seq.),  and any  analogous
federal,   state,  local  or  foreign,  Laws,  and  the  rules  and  regulations
promulgated  thereunder all as from time to time in effect, and any reference to
any statutory or regulatory  provision  shall be deemed to be a reference to any
successor statutory or regulatory provision.

         Environmental Permit shall mean any Governmental Authorization required
by or pursuant to any Environmental Law.

         Environmental  Reports  shall have the  meaning  given to it in Section
7.9.

         ERISA shall mean the Employee  Retirement  Income Security Act of 1974,
and the rules and regulations thereunder, all as from time to time in effect, or
any successor law, rules or  regulations,  and any reference to any statutory or
regulatory  provision  shall  be  deemed  to be a  reference  to  any  successor
statutory or regulatory provision.

         ERISA  Affiliate  shall  mean any  Person  that is  treated as a single
employer  with Gearon  under  Sections  414(b),  (c),  (m) or (o) of the Code or
Section 4001(b)(1) of ERISA.

                                       A-4


<PAGE>



         Event  shall  mean the  existence  or  occurrence  of any act,  action,
activity,  circumstance,  condition,  event,  fact,  failure  to act,  omission,
incident or practice, or any set or combination of any of the foregoing.

         Exchange Act shall mean the  Securities  Exchange Act of 1934,  and the
rules and  regulations  thereunder,  all as from time to time in effect,  or any
successor  law,  rules or  regulations,  and any  reference to any  statutory or
regulatory  provision  shall  be  deemed  to be a  reference  to  any  successor
statutory or regulatory provision.

         Exchange  Merger  Consideration  shall have the meaning  given to it in
Section 3.1(b).

         FCA  shall  mean the  Communications  Act of 1934,  and the  rules  and
regulations  thereunder,  all as from time to time in effect,  or any  successor
law,  rules or  regulations,  and any  reference to any  statutory or regulatory
provision  shall be deemed  to be a  reference  to any  successor  statutory  or
regulatory provision.

         FCC shall mean the Federal Communications  Commission and shall include
any successor Authority.

         Final  Order  shall  mean,  with  respect to any  Authority,  including
without  limitation  the FCC, one with respect to which no appeal,  no stay,  no
petition or application for rehearing, reconsideration,  review or stay, whether
on motion of the applicable Authority or other Person or otherwise, and no other
Legal Action contesting such consent or approval, is in effect or pending and as
to  which  the  time or  deadline  for  filing  any  such  appeal,  petition  or
application  or other Legal  Action has expired or, if filed,  has been  denied,
dismissed or  withdrawn,  and the time or deadline for  instituting  any further
Legal Action has expired.

         GAAP shall mean generally accepted  accounting  principles applied on a
consistent  basis,  (i) as set forth in  Opinions of the  Accounting  Principles
Board of the American Institute of Certified Public Accountants ("AICPA") and/or
in statements of the Financial Accounting Standards Board that are applicable in
the  circumstances as of the date in question,  (ii) when not inconsistent  with
such  opinions  and  statements,  as set forth in other AICPA  publications  and
guidelines  and/or  (iii)  that  otherwise  arise by custom  for the  particular
industry, all as the same shall exist on the date of this Agreement.

         Gearon  shall have the meaning  given to it in the  Preamble  and shall
include  CTI,  it being  understood,  without  limiting  the  generality  of the
foregoing,  that the  representations  and warranties set forth in Article 4 and
the Gearon  Disclosure  Schedule assume that the CTI Merger had been consummated
immediately  prior to the date of this Agreement,  except as otherwise set forth
in the Gearon Disclosure Schedule.

         Gearon Assets shall have the meaning given to it in Section 4.4(a).

         Gearon Business shall have the meaning given to it in Section 4.4(b).

         Gearon Common Stock Consideration shall have the meaning given to it in
Section 3.1(b).

         Gearon Disclosure  Schedule shall mean the Gearon  Disclosure  Schedule
dated as of the date of this Agreement delivered by Gearon to ATS.

         Gearon Employees shall have the meaning given it in Section 4.14.

         Gearon  Employees  Consideration  shall have the meaning given to it in
Section 3.1(b).


                                       A-5


<PAGE>



         Gearon  Employment  Agreement  shall  have the  meaning  given to it in
Section 8.2(n).

         Gearon  Financial  Statements  shall  have the  meaning  given to it in
Section 4.2.

         Gearon Investment Letters shall have the meaning given to it in Section
8.2(r).

         Gearon Notes shall have the meaning given to it in Section 7.10.

         Gearon Security Agreement shall have the meaning given to it in Section
7.10.

         Gearon Shares shall have the meaning given to it in Section 3.1(b).

         Gearon Stockholder shall have the meaning given to it in the Preamble.

         Gearon's  knowledge (or words of similar  import) shall mean the actual
knowledge of the Gearon  Stockholder or any Gearon director or officer,  as such
knowledge  exists  on the date of this  Agreement,  after  reasonable  review of
appropriate  Gearon records and after reasonable  inquiry of appropriate  Gearon
employees.

         Governmental  Authorizations  shall  mean all  approvals,  concessions,
consents,   franchises,   licenses,  permits,  plans,  registrations  and  other
authorizations  of all  Authorities,  including  without  limitation  the United
States Forest  Service and the Federal  Aviation  Administration,  in connection
with the  ownership  or  operation  of the Gearon  Assets or the  conduct of the
Gearon Business.

         Governmental  Filings shall mean all filings,  including  franchise and
similar Tax  filings,  and the payment of all fees,  assessments,  interest  and
penalties associated with such filings, with all Authorities.

         Hart-Scott-Rodino Act shall mean the Hart-Scott-Rodino  Improvement Act
of 1976, as from time to time in effect, or any successor law, and any reference
to any  statutory  provision  shall be deemed to be a reference to any successor
statutory provision.

         Hazardous  Materials  shall mean and include any  substance,  material,
waste, constituent, compound, chemical, natural or man-made element or force (in
whatever state of matter):  (a) the presence of which requires  investigation or
remediation under any Environmental  Law, or (b) that is defined as a "hazardous
waste" or  "hazardous  substance"  under any  Environmental  Law; or (c) that is
toxic, explosive,  corrosive,  etiologic,  flammable,  infectious,  radioactive,
carcinogenic,   mutagenic  or  otherwise  hazardous  and  is  regulated  by  any
applicable Authority or subject to any Environmental Law; or (d) the presence of
which on the real property owned or leased by such Person causes or threatens to
cause a nuisance upon any such real property or to adjacent  properties or poses
or threatens to pose a hazard to the health or safety of persons on or about any
such real property;  or (e) the presence of which on adjacent  properties  could
constitute a trespass by such Person; or (f) that contains gasoline, diesel fuel
or other  petroleum  hydrocarbons,  or any  by-products  or  fractions  thereof,
natural gas,  polychlorinated  biphenyls ("PCBs") and PCB-containing  equipment,
radon or other radioactive elements,  ionizing radiation,  electromagnetic field
radiation  and other  non-ionizing  radiation,  sonic  forces and other  natural
forces,  lead,  asbestos  or  asbestos-containing  materials  ("ACM"),  or  urea
formaldehyde foam insulation.

         Indebtedness  shall mean,  with  respect to any Person,  (a) all items,
except  items of  capital  stock or of  surplus  or of  general  contingency  or
deferred tax reserves or any minority interest in any Subsidiary of such

                                       A-6


<PAGE>



Person to the extent such interest is treated as a liability with  indeterminate
term on the consolidated  balance sheet of such Person, which in accordance with
GAAP  would  be  included  in  determining  total  liabilities  as  shown on the
liability side of a balance sheet of such Person, (b) all obligations secured by
any Lien to which any property or asset owned or held by such Person is subject,
whether or not the obligation  secured thereby shall have been assumed,  and (c)
to the extent not otherwise included, all Contractual Obligations of such Person
constituting  capitalized leases and all obligations of such Person with respect
to Leases constituting part of a sale and leaseback arrangement.

         Indebtedness  for Money  Borrowed  shall mean,  with respect to Gearon,
money borrowed and Indebtedness represented by notes payable and drafts accepted
representing   extensions  of  credit,  all  obligations   evidenced  by  bonds,
debentures,  notes or other similar instruments, the maximum amount currently or
at any time thereafter  available to be drawn under all  outstanding  letters of
credit  issued  for the  account of such  Person,  all  Indebtedness  upon which
interest  charges are  customarily  paid by such  Person,  and all  Indebtedness
(including  capitalized lease obligations)  issued or assumed as full or partial
payment  for  property  or  services,  whether  or not any such  notes,  drafts,
obligations or Indebtedness represent Indebtedness for money borrowed, but shall
not include (a) trade payables,  (b) expenses  accrued in the ordinary course of
business,  (c) customer advance payments and customer  deposits  received in the
ordinary course of business,  or (d) conditional sales agreements not prohibited
by the terms of this Agreement.

         Indemnity  Escrow  Agreement  shall  have  the  meaning  given to it in
Section 8.2(o).

         Intangible  Assets shall mean all assets and property  lacking physical
properties the evidence of ownership of which must  customarily be maintained by
independent  registration,  documentation,  certification,  recordation or other
means,  and  shall  include,   without  limitation,   concessions,   copyrights,
franchises,  license, patents, permits, service marks, trademarks,  trade names,
and applications with respect to any of the foregoing, technology and know-how.

         Intellectual  Property  shall mean any and all  research,  information,
inventions,  designs,  procedures,  developments,   discoveries,   improvements,
patents and applications therefor, trademarks and applications therefor, service
marks, trade names, copyrights and applications therefor,  logos, trade secrets,
drawing, plans, systems,  methods,  specifications,  computer software programs,
tapes, discs and related data processing  software (including without limitation
object and source  codes)  owned by such Person or in which it has an  ownership
interest  and all other  manufacturing,  engineering,  technical,  research  and
development data and know-how made, conceived, developed and/or acquired by such
Person,  which  relate  to the  manufacture,  production  or  processing  of any
products  developed  or sold by such  Person or which are within the scope of or
usable in connection  with such Person's  business as it may, from time to time,
hereafter be conducted or proposed to be conducted.

         Law shall mean any (a) administrative,  judicial,  legislative or other
action,  code,  consent  decree,  constitution,  decree,  directive,  enactment,
finding, law, injunction,  interpretation,  judgment,  order, ordinance,  policy
statement, proclamation,  promulgation,  regulation,  requirement, rule, rule of
law,  rule of  public  policy,  settlement  agreement,  statute,  or writ of any
Authority, domestic or foreign; (b) the common law, or other legal precedent; or
(c)  arbitrator's,   mediator's  or  referee's  award,   decision,   finding  or
recommendation.

         Lease  shall mean any lease of  property,  whether  real,  personal  or
mixed, and all amendments thereto.

         Legal  Action  shall  mean,  with  respect to any  Person,  any and all
litigation   or   legal   or   other   actions,   arbitrations,   counterclaims,
investigations, proceedings, requests for material information by or pursuant to

                                       A-7


<PAGE>



the  order of any  Authority  or  suits,  at law or in  arbitration,  equity  or
admiralty,  whether or not  purported  to be  brought on behalf of such  Person,
affecting such Person or any of such Person's business, property or assets.

         Lien shall mean any of the  following:  mortgage;  lien  (statutory  or
other);  or other security  agreement,  arrangement or interest;  hypothecation,
pledge  or  other  deposit  arrangement;  assignment;  charge;  levy;  executory
seizure;   attachment;   garnishment;   encumbrance   (including  any  easement,
exception,  reservation or limitation,  right of way, and the like); conditional
sale,  title  retention  or other  similar  agreement,  arrangement,  device  or
restriction;   preemptive  or  similar  right;  any  financing  lease  involving
substantially  the same economic  effect as any of the foregoing;  the filing of
any financing  statement under the Uniform  Commercial Code or comparable law of
any  jurisdiction;  restriction on sale,  transfer,  assignment,  disposition or
other alienation; or any option, equity, claim or right of or obligation to, any
other Person, of whatever kind and character.

         Loss and Expense shall have the meaning given to it in Section 10.2(a).

         material, materially or materiality for the purposes of this Agreement,
shall, unless specifically stated to the contrary,  be determined without regard
to the fact that various  provisions of this Agreement set forth specific dollar
amounts.

         Material  Agreement shall mean, with respect to Gearon, any Contractual
Obligation  which (a) was not entered into in the  ordinary  course of business,
(b) was entered into in the ordinary  course of business  which (i) involved the
purchase,  sale or lease  of  goods  or  materials,  or  purchase  of  services,
aggregating  more than $50,000  during any of the last three fiscal years,  (ii)
extends for more than three (3)  months,  or (iii) is not  terminable  on thirty
(30) days or less  notice  without  penalty  or other  payment,  (c)  involves a
capitalized  lease  obligation or  Indebtedness  for Money  Borrowed,  (d) is or
otherwise   constitutes   a   written   agency,   broker,    dealer,    license,
distributorship,   sales  representative  or  similar  written  agreement,   (e)
accounted  for more  than  three  percent  (3%) of the  revenues  of the  Gearon
Business in any of the last three  fiscal years or is likely to account for more
than three  percent (3%) of revenues of the Gearon  Business  during the current
fiscal  year,  (f) is  with  the  United  States  Forest  Service  or any  other
Authority,  or (g) involves the management by Gearon of any communication  tower
of any other Person.

         Merger  shall  have  the  meaning  given  to it in  the  first  Whereas
paragraph.

         Merger  Consideration  shall  have the  meaning  given to it in Section
3.1(b).

         Multiemployer  Plan shall mean a Plan which is a  "multiemployer  plan"
within the meaning of Section 4001(a)3 of ERISA.

         Net Working Capital shall mean,  with respect to Gearon,  the amount by
which (a) the sum of (i) the current  assets of Gearon and (ii) all amounts paid
by Gearon  subsequent  to October 31, 1997 with respect to the  construction  of
communications  towers, exceeds (or is less than) (b) the sum of (i) the current
liabilities  of Gearon,  and,  without  duplication,  (ii) the  principal on any
Indebtedness,  all as determined in accordance  with GAAP  consistently  applied
with the Gearon Financial Statements.

         Option  Securities  shall mean all rights,  options and  warrants,  and
calls or  commitments  evidencing  the right,  to  subscribe  for,  purchase  or
otherwise acquire shares of capital stock or Convertible Securities,  whether or
not the right to subscribe  for,  purchase or otherwise  acquire is  immediately
exercisable or is

                                       A-8


<PAGE>



conditioned  upon the passage of time, the occurrence or  non-occurrence  or the
existence or non-existence of some other Event.

         Operating Cash Flow shall mean, with respect to Gearon, for any period:
(a) net revenues of Gearon, determined in accordance with GAAP, for such period,
less (b) operating expenses (inclusive of taxes and corporate overhead,  selling
and administrative expenses);  provided,  however, that such corporate overhead,
selling and  administrative  expenses  shall not include (i) non-cash  operating
expenses,  (ii) any expense attributable to the issue of shares of Gearon Common
Stock to the  Gearon  stockholders  listed in  Section  3.1(b)(i),  or (iii) any
expenses attributable to special cash bonuses paid to Gearon stockholders to the
extent  such  bonuses  are  funded  out of the  sum of Net  Working  Capital  at
September 30, 1997 and cash capital  contributions  made to Gearon by the Gearon
Stockholder subsequent to September 30, 1997.

         Organic  Document  shall  mean,  with  respect  to a Person  which is a
corporation,  its charter,  its by-laws and all shareholder  agreements,  voting
trusts and similar arrangements applicable to any of its capital stock and, with
respect to a Person which is a  partnership,  its agreement and  certificate  of
partnership,  any  agreements  among  partners,  and any  management and similar
agreements  between the partnership  and any general  partners (or any Affiliate
thereof).

         PBGC shall mean the Pension Benefit Guaranty Corporation and any Entity
succeeding to any or all of its functions under ERISA.

         Permitted  Liens shall mean (a) Liens for current taxes not yet due and
payable, (b) such imperfections of title, easements,  encumbrances and mortgages
or  other  Liens,  if  any,  as  are  not,  individually  or in  the  aggregate,
substantial in character,  amount or extent and do not  materially  detract from
the value, or materially interfere with the present use, of the property subject
thereto or affected thereby,  or otherwise  materially impair the conduct of the
Gearon  Business or the  businesses of ATS and ATSI, as the case may be, and (c)
such other Liens as are permitted by the  provisions of this  Agreement to be in
place on the Closing Date.

         Person shall mean any natural individual or any Entity.

         Personal  Property shall mean all of the machinery,  equipment,  tools,
vehicles, furniture, leasehold improvements, office equipment, plant, inventory,
spare parts and other  tangible  personal  property which are owned or leased by
Gearon and used or useful as of the date hereof in the  conduct of the  business
or operations of the Gearon Business,  plus such additions thereto and deletions
therefrom arising in the ordinary course of business between the date hereof and
the Closing Date.

         Plan shall mean,  with respect to any Person and at a particular  time,
any employee benefit plan which is covered by ERISA and in respect of which such
Person or an ERISA  Affiliate is (or, if such plan were terminated at such time,
would under  Section 4069 of ERISA be deemed to be) an  "employer" as defined in
Section  3(5) of ERISA,  but only to the extent that it covers or relates to any
officer, employee or other Person involved in the ownership and operation of the
Gearon Assets or the conduct of the business of the Gearon Business.

         Private Authorizations shall mean all approvals, concessions, consents,
franchises,  licenses,  permits,  and other authorizations of all Persons (other
than   Authorities)   including   without   limitation  those  with  respect  to
Intellectual Property.


                                       A-9


<PAGE>



         Real Property shall mean all of the fee estates and buildings and other
fixtures and improvements  thereon,  leasehold  interest,  easements,  licenses,
rights to access,  right-of-  way, and other real  property  interest  which are
owned or used by Gearon as of the date hereof,  in the  operations of the Gearon
Business,  plus such additions  thereto and deletions  therefrom  arising in the
ordinary course of business between the date hereof and the Closing Date.

         Registration  Rights  Agreement  shall have the meaning  given to it in
Section 8.2(p)

         Regulations  shall mean the federal income tax regulations  promulgated
under  the Code,  as such  Regulations  may be  amended  from time to time.  All
references  herein to specific  sections of the Regulations shall be deemed also
to refer to any  corresponding  provisions  of succeeding  Regulations,  and all
references  to  temporary  Regulations  shall  be  deemed  also to  refer to any
corresponding provisions of final Regulations.

         Representatives shall have the meaning given to it in Section 7.1(a).

         Securities Act shall mean the Securities Act of 1933, and the rules and
regulations  thereunder,  all as from time to time in effect,  or any  successor
law,  rules or  regulations,  and any  reference to any  statutory or regulatory
provision  shall be deemed  to be a  reference  to any  successor  statutory  or
regulatory provision.

         Settlement Proposal shall have the meaning given to it in Section 10.5.

         Solvent  shall mean,  with respect to any Person on a particular  date,
that on such date (i) the fair value of the assets of such Person  (both at fair
valuation and at present fair saleable value) is, on the date of  determination,
greater than the total amount of  liabilities,  including,  without  limitation,
contingent and  unliquidated  liabilities,  of such Person,  (ii) such Person is
able to pay all liabilities of such Person as they mature, and (iii) such Person
does not have unreasonably small capital with which to carry on its business. In
computing the amount of contingent or unliquidated liabilities at any time, such
liabilities  will be computed at the amount which, in light of all the facts and
circumstances  existing at such time,  represents the amount that can reasonably
be  expected  to become an actual or matured  liability.  For  purposes  of this
definition,  "indebtedness"  shall mean any  liability  on a claim,  and "claim"
shall  mean (a)  right to  payment,  whether  or not such  right is  reduced  to
judgment,  liquidated,  unliquidated,  fixed,  contingent,  matured,  unmatured,
disputed,  undisputed, legal equitable, secured or unsecured, or (b) right to an
equitable  remedy  for  breach of  performance  if such  breach  gives rise to a
payment,  whether  or not such  right  to an  equitable  remedy  is  reduced  to
judgment, fixed, contingent,  matured, unmatured,  disputed, undisputed, secured
or unsecured.

         Subsidiary shall mean, with respect to a Person,  any Entity a majority
of the capital stock  ordinarily  entitled to vote for the election of directors
of which,  or if no such voting stock is  outstanding,  a majority of the equity
interests of which, is owned directly or indirectly, legally or beneficially, by
such Person or any other Person controlled by such Person.

         Surviving  Corporation  shall have the  meaning  given to it in Section
2.1.

         Tax (and "Taxable",  which shall mean subject to Tax), shall mean, with
respect to any Person,  (a) all taxes (domestic or foreign),  including  without
limitation any income (net, gross or other including  recapture of any tax items
such as  investment  tax  credits),  alternative  or add-on  minimum tax,  gross
income,  gross receipts,  gains,  sales, use, leasing,  lease, user, ad valorem,
transfer, recording, franchise, profits, property (real or personal, tangible or
intangible),  fuel,  license,  withholding on amounts paid to or by such Person,
payroll,

                                      A-10


<PAGE>


employment, unemployment, social security, excise, severance, stamp, occupation,
premium,  environmental  or windfall profit tax,  custom,  duty or other tax, or
other  like  assessment  or charge  of any kind  whatsoever,  together  with any
interest, levies, assessments, charges, penalties, addition to tax or additional
amount imposed by any Taxing  Authority,  (b) any joint or several  liability of
such  Person  with any other  Person for the  payment of any amounts of the type
described  in (a) and (c) any  liability  of such  Person for the payment of any
amounts  of the type  described  in (a) as a result of any  express  or  implied
obligation to indemnify any other Person.

         Tax Return or Returns shall mean all returns, consolidated or otherwise
(including without limitation  information  returns),  required to be filed with
any Authority with respect to Taxes.

         Taxing   Authority  shall  mean  any  Authority   responsible  for  the
imposition of any Tax.

         Title Reports shall have the meaning given to it in Section 7.8.

         Termination Date shall have the meaning given to it in Section 9.1.

         Transactions shall mean the transactions contemplated to be consummated
on or prior to the Closing Date, including without limitation the Merger and the
execution, delivery and performance of the Collateral Documents.



                                      A-11



                                                                     EXHIBIT 2.3

                AMENDED AND RESTATED AGREEMENT AND PLAN OF MERGER

                                  By and Among

                       AMERICAN RADIO SYSTEMS CORPORATION,

                                 CBS CORPORATION

                                       and

                               R ACQUISITION CORP.

                                   Dated as of

                                December 18, 1997












<PAGE>

<TABLE>
<CAPTION>

                                TABLE OF CONTENTS

<S>              <C>                                                                                            <C>

ARTICLE 1         DEFINED TERMS...................................................................................1

ARTICLE 2         THE MERGER......................................................................................2
                  2.1      The Merger.............................................................................2
                  2.2      Closing................................................................................2
                  2.3      Effective Time.........................................................................2
                  2.4      Effect of the Merger...................................................................2
                  2.5      Certificate of Incorporation...........................................................2
                  2.6      Bylaws.................................................................................2
                  2.7      Directors and Officers.................................................................2

ARTICLE 3         CONVERSION OF SHARES; EXCHANGE OF CERTIFICATES..................................................3
                  3.1      Conversion of Capital Stock............................................................3
                  3.2      Exchange of Certificates.  ............................................................4
                  3.3      Closing of American's Transfer Books...................................................5
                  3.4      Dissenting Shares......................................................................6
                  3.5      Tower Merger...........................................................................6

ARTICLE 4         REPRESENTATIONS AND WARRANTIES OF AMERICAN......................................................8
                  4.1      Organization and Business; Power and Authority; Effect of Transaction..................8
                  4.2      Financial and Other Information.  ....................................................11
                  4.3      Changes in Condition..................................................................11
                  4.4      Properties............................................................................11
                  4.5      Compliance with Private Authorizations................................................11
                  4.6      Compliance with Governmental Authorizations and Applicable Law;
                           Litigation............................................................................12
                  4.7      Related Transactions..................................................................13
                  4.8      Taxes and Tax Matters.................................................................13
                  4.9      Employee Retirement Income Security Act of 1974.......................................14
                  4.10     Insurance.............................................................................17
                  4.11     Authorized Capital Stock..............................................................17
                  4.12     Employment Arrangements...............................................................18
                  4.14     Brokers...............................................................................18
                  4.15     Information Supplied..................................................................18
                  4.16     Ordinary Course of Business...........................................................19
                  4.17     Environmental Matters.................................................................19
                  4.18     Opinion of Financial Advisor..........................................................20
                  4.19     Contracts; Debt Instruments...........................................................20
                  4.20     State Takeover Statutes...............................................................21
                  4.21     Appraisal Rights......................................................................21

ARTICLE 5         REPRESENTATIONS AND WARRANTIES OF MERGEPARTY...................................................21
                  5.1      Organization and Business; Power and Authority; Effect of Transaction.................21
                  5.2      Compliance with Governmental Authorizations and Applicable Law;
                           Litigation............................................................................22
                  5.3      Mergeparty Financing..................................................................23


                                      

<PAGE>



ARTICLE 6         COVENANTS......................................................................................23
                  6.1      Access to Information; Confidentiality................................................23
                  6.2      Agreement to Cooperate................................................................23
                  6.3      Public Announcements..................................................................26
                  6.4      Notification of Certain Matters.......................................................26
                  6.5      Stockholder Approval. ................................................................26
                  6.6      Proxy Statement; Registration Statement.  ............................................26
                  6.7      Miscellaneous.........................................................................27
                  6.8      Option Plans..........................................................................27
                  6.9      Conduct of Business by Mergeparty Pending the Merger..................................29
                  6.10     Conduct of Business by American Pending the Merger....................................29
                  6.11     Control of Operations.................................................................31
                  6.12     Directors', Officers' and Employees' Indemnification and Insurance....................31
                  6.13     Solicitation of Employees.............................................................32
                  6.14     Change of Name........................................................................33
                  6.15     Benefit Plans.........................................................................33
                  6.16     American Cumulative Preferred Stock...................................................33
                  6.17     American Tower Transaction............................................................33
                  6.18     Purchase Price Adjustment.............................................................39
                  6.19     Tower Leases..........................................................................41
                  6.20     Affiliates of American................................................................42

ARTICLE 7         CLOSING CONDITIONS.............................................................................42
                  7.1      Conditions to Obligations of Each Party to Effect the Merger..........................42
                  7.2      Conditions to Obligations of Mergeparty...............................................43
                  7.3      Conditions to Obligations of American.................................................44

ARTICLE 8         TERMINATION, AMENDMENT AND WAIVER..............................................................44
                  8.1      Termination...........................................................................44
                  8.2      Effect of Termination.
                   ..............................................................................................45

ARTICLE 9         GENERAL PROVISIONS.............................................................................46
                  9.1      Amendment.............................................................................46
                  9.2      Waiver................................................................................46
                  9.3      Fees, Expenses and Other Payments.....................................................46
                  9.4      Notices...............................................................................47
                  9.5      Specific Performance; Other Rights and Remedies.......................................47
                  9.6      Survival of Representations, Warranties, Covenants and Agreements.....................48
                  9.7      Severability..........................................................................48
                  9.8      Counterparts..........................................................................48
                  9.9      Section Headings......................................................................48
                  9.10     Governing Law.........................................................................48
                  9.11     Further Acts..........................................................................48
                  9.12     Entire Agreement; No Other Representations or Agreements..............................49
                  9.13     Assignment............................................................................49
                  9.14     Parties in Interest...................................................................49
                  9.15     Mutual Drafting.......................................................................49
                  9.16     Obligations of American and of Mergeparty.............................................50

                                      -ii-

<PAGE>

                  9.17     Mergeparty Agent for Mergeparty Subsidiary............................................50



APPENDIX A:                Definitions

EXHIBITS:

         EXHIBIT A:        Restated Certificate of Incorporation
         EXHIBIT B:        Market Fee Schedule
         EXHIBIT C:        Form of Opinion of FCC Counsel to American
         EXHIBIT D:        Tower Merger Agreement

SCHEDULES:                 Schedule 4.1(e)
</TABLE>

                                      -iii-

<PAGE>



                AMENDED AND RESTATED AGREEMENT AND PLAN OF MERGER


         Amended and Restated Agreement and Plan of Merger, dated as of December
18,  1997,  by  and  among  American  Radio  Systems  Corporation,   a  Delaware
corporation  ("American"),  CBS  Corporation  (formerly,  Westinghouse  Electric
Corporation),  a  Pennsylvania  corporation  ("Mergeparty"),  and R  Acquisition
Corp., a Delaware corporation ("Mergeparty Subsidiary").

                              W I T N E S S E T H:

         WHEREAS, American,  Mergeparty and Mergeparty Subsidiary are parties to
an Agreement and Plan of Merger,  dated as of September 19, 1997 (the  "Original
Merger Agreement"),  providing for the merger of Mergeparty  Subsidiary with and
into American on the terms and conditions set forth therein; and

         WHEREAS, American, Mergeparty and Mergeparty Subsidiary desire to amend
and  restate the  Original  Merger  Agreement  in its  entirety to make  certain
changes to the Original Merger Agreement; and

         WHEREAS,  American,  Mergeparty and Mergeparty  Subsidiary have entered
into this Amended and Restated  Agreement and Plan of Merger (this  "Agreement")
providing  that  Mergeparty  Subsidiary  shall be merged with and into American,
which shall be the surviving corporation,  on the terms and conditions set forth
in this Agreement (the "Merger").

         NOW,   THEREFORE,   in   consideration   of  the   premises   and   the
representations, warranties, covenants and agreements herein contained and other
valuable   consideration,   the   receipt  and   adequacy   whereof  are  hereby
acknowledged,  the  parties  hereto  hereby,  intending  to  be  legally  bound,
represent, warrant, covenant and agree as follows:

                                    ARTICLE 1

                                  DEFINED TERMS

         As used  herein,  unless  the  context  otherwise  requires,  the terms
defined in  Appendix A shall have the  respective  meanings  set forth  therein.
Terms defined in the singular  shall have a comparable  meaning when used in the
plural,  and vice  versa,  and the  reference  to any gender  shall be deemed to
include all genders.  Unless otherwise  defined or the context otherwise clearly
requires,  terms for which  meanings are provided in this  Agreement  shall have
such  meanings  when  used in either  Disclosure  Schedule  and each  Collateral
Document  executed  or required  to be  executed  pursuant  hereto or thereto or
otherwise delivered,  from time to time, pursuant hereto or thereto.  References
to "hereof," "herein" or similar terms are intended to refer to the Agreement as
a whole and not a particular section,  and references to "this Section" or "this
Article"  are  intended  to refer to the entire  section  or  article  and not a
particular subsection thereof. The term "either party" shall, unless the context
otherwise  requires,  refer to American,  on the one hand,  and  Mergeparty  and
Mergeparty Subsidiary, on the other hand.




<PAGE>



                                    ARTICLE 2

                                   THE MERGER

         2.1 The Merger.  (a) Upon the terms and subject to the  conditions  set
forth in this Agreement, and in accordance with the Delaware General Corporation
Law (the "DCL"),  at the Effective Time,  Mergeparty  Subsidiary shall be merged
with and into  American.  As a result  of the  Merger,  the  separate  corporate
existence of Mergeparty  Subsidiary  shall cease and American  shall continue as
the surviving  corporation in the Merger (sometimes referred to, as such, as the
"Surviving Corporation").

         2.2 Closing.  Unless this Agreement shall have been terminated pursuant
to Section 8.1 and subject to the  satisfaction  or, to the extent  permitted by
Applicable  Law, waiver of the conditions set forth in Article 7, the closing of
the Merger (the  "Closing") will take place, at 10:00 a.m., on the Closing Date,
at the offices of Cravath, Swaine & Moore, 825 Eighth Avenue, New York, New York
10019,  on the date that is the second  (2nd) day after the date on which all of
the conditions  set forth in Article 7 (other than those which require  delivery
of opinions or documents at the  Closing)  shall have been  satisfied or waived,
unless another date,  time or place is agreed to in writing by the parties.  The
date on which the Closing occurs is herein referred to as the "Closing Date."

         2.3 Effective  Time.  Subject to the provisions of this  Agreement,  as
promptly as  practicable  after the Closing,  the parties hereto shall cause the
Merger to be consummated by filing a certificate of merger (the  "Certificate of
Merger") and any related  filings  required  under the DCL with the Secretary of
State of the State of Delaware.  The Merger shall become  effective at such time
as such  documents  are duly filed with the  Secretary  of State of the State of
Delaware,  or at  such  later  time  as is  specified  in  such  documents  (the
"Effective Time").

         2.4 Effect of the Merger.  The Merger  shall have the effects  provided
for under the DCL.

         2.5 Certificate of  Incorporation.  The Certificate of Incorporation of
American, as in effect immediately prior to the Effective Time, shall be amended
as of the Effective  Time to read in its entirety as set forth in Exhibit A and,
as so amended, such Certificate of Incorporation, together with the Certificates
of Designation of (i) 113/8% Series B Cumulative  Exchangeable  Preferred Stock,
par value $.01 per share, of American  ("American  Cumulative  Preferred Stock")
and (ii) 7% Convertible  Exchangeable Preferred Stock, par value $.01 per share,
of American  ("American  Convertible  Preferred  Stock" and,  collectively  with
American Cumulative Preferred Stock,  "American Preferred Stock"),  shall be the
Certificate  of  Incorporation  of the Surviving  Corporation  until  thereafter
changed or amended as provided  therein or by  Applicable  Law.  Such  amendment
shall not be deemed to affect in any manner the  Certificates  of Designation of
American Preferred Stock.

         2.6  Bylaws.  The bylaws of American  in effect at the  Effective  Time
shall be the bylaws of the  Surviving  Corporation  until  amended in accordance
with Applicable Law and the Organic Documents of the Surviving Corporation.

         2.7 Directors and Officers.  From and after the Effective  Time,  until
successors  are duly elected or appointed and  qualified,  or upon their earlier
resignation  or  removal,  in  accordance  with  Applicable  Law and the Organic
Documents  of  the  Surviving  Corporation,  (a)  the  directors  of  Mergeparty
Subsidiary  at the  Effective  Time  shall  be the  directors  of the  Surviving
Corporation, and (b) the officers of American at the Effective Time shall be the
officers of the Surviving Corporation.



                                       -2-


<PAGE>



                                    ARTICLE 3

                 CONVERSION OF SHARES; EXCHANGE OF CERTIFICATES

         3.1  Conversion of Capital Stock.  At the Effective  Time, by virtue of
the  Merger  and  without  any  action  on the  part of  Mergeparty,  Mergeparty
Subsidiary or American or their respective stockholders:

         (a)  Each  share of  Common  Stock,  par  value  $1.00  per  share,  of
Mergeparty Subsidiary issued and outstanding  immediately prior to the Effective
Time  shall be  converted  into and become one  validly  issued,  fully paid and
nonassessable  share of Common Stock, par value $.01 per share, of the Surviving
Corporation;

         (b) Each  share of  American  Cumulative  Preferred  Stock  issued  and
outstanding immediately prior to the Effective Time shall remain outstanding;

         (c) Each  share of  American  Convertible  Preferred  Stock  issued and
outstanding immediately prior to the Effective Time shall remain outstanding;

         (d) Subject to paragraph (e) below, each share of Class A Common Stock,
par value  $.01 per share  ("American  Class A  Common"),  each share of Class B
Common Stock,  par value $.01 per share  ("American  Class B Common"),  and each
share of Class C Common  Stock,  par  value  $.01 per share  ("American  Class C
Common" and,  collectively  with  American  Class A Common and American  Class B
Common, "American Common Stock"), of American issued and outstanding immediately
prior to the Effective  Time (other than  Dissenting  Shares) shall be converted
into the right to receive the following:

                  (i)  if  the  Tower  Merger  Effective  Time  shall  not  have
         occurred,  (A) $44.00 in cash and (B) one share of Tower Common  Stock,
         with (x) each share of American Class A Common being converted into the
         right to receive one share of Class A Common Stock,  par value $.01 per
         share ("Tower Class A Common"),  of American Tower Systems Corporation,
         a  Delaware  corporation  and a  wholly-owned  Subsidiary  of  American
         ("American  Tower"),  (y) each share of American  Class B Common  being
         converted  into the right to receive one share of Class B Common Stock,
         par value $.01 per share ("Tower Class B Common"),  of American  Tower,
         and (z) each share of American Class C Common being  converted into the
         right to receive one share of Class C Common Stock,  par value $.01 per
         share  ("Tower  Class C Common"  and,  collectively  with Tower Class A
         Common and Tower Class B Common,  "Tower  Common  Stock"),  of American
         Tower (collectively, the "Tower Stock Consideration"); or

                  (ii) if the Tower Merger  Effective  Time shall have occurred,
         an  amount  in cash  determined  by  dividing  $44.00  by the  American
         Conversion Fraction.

The term "Cash Consideration" shall mean the following:  (x) if the Tower Merger
Effective  Time shall not have  occurred,  $44.00,  and (y) if the Tower  Merger
Effective Time shall have occurred,  the amount of cash  determined  pursuant to
the provisions of clause (ii) preceding.  The term "Merger  Consideration" shall
mean the Cash  Consideration  and, if the Tower Merger  Effective Time shall not
have occurred, the Tower Stock Consideration.

         (e) Each share of American Common Stock owned by American or any of its
Subsidiaries or Mergeparty or any of its Subsidiaries  immediately  prior to the
Effective  Time shall  automatically  be canceled and  extinguished  without any
conversion thereof and no payment shall be made with respect thereto.


                                       -3-


<PAGE>



         As a result of the  Merger  and  without  any action on the part of the
holder thereof,  at the Effective Time all shares of American Common Stock shall
cease to be  outstanding  and shall be  canceled  and retired and shall cease to
exist, and each holder of any  certificates  formerly  representing  such shares
shall thereafter  cease to have any rights with respect to such shares,  except,
subject to paragraph  (e) above,  the right to receive,  without  interest,  the
Merger  Consideration,  or, in the case of a holder of  Dissenting  Shares,  the
right to perfect the right to receive payment for Dissenting  Shares pursuant to
Section 262 of the DCL.

         3.2      Exchange of Certificates.

         (a) From  time to time,  on or prior to or after  the  Effective  Time,
Mergeparty  shall  deposit  or  cause to be  deposited  with an  exchange  agent
selected by  Mergeparty  and not  reasonably  disapproved  of by  American  (the
"Exchange  Agent") in trust for the benefit of the  holders of  American  Common
Stock cash in amounts and at times  necessary for the prompt payment of the Cash
Consideration,  and American  shall  deposit or cause to be  deposited  with the
Exchange Agent in trust for the benefit of the holders of American  Common Stock
shares of Tower  Common Stock in amounts and at times  necessary  for the prompt
delivery  of the  Tower  Stock  Consideration,  if any,  upon the  surrender  of
Certificates.

         (b) Not more than five (5) business  days  subsequent  to the Effective
Time, the Exchange Agent shall mail to each holder of record of a certificate or
certificates   that   immediately   prior  to  the  Effective  Time  represented
outstanding shares of American Common Stock (the "Certificates") (i) a letter of
transmittal  (which shall specify that delivery  shall be effected,  and risk of
loss and title to the Certificates  shall pass, only upon actual delivery of the
Certificates to the Exchange Agent and shall be in such form and have such other
provisions as American and Mergeparty may agree) and (ii)  instructions  for use
in  effecting  the  surrender  of the  Certificates  in exchange  for the Merger
Consideration.  Upon surrender of Certificates  for cancellation to the Exchange
Agent,  together  with a duly  executed  letter of  transmittal  and such  other
documents as the Exchange  Agent shall  reasonably  require,  the holder of such
Certificate  shall  receive  in  exchange  therefor  the  Merger   Consideration
multiplied by the number of shares of American Common Stock formerly represented
by such  Certificates.  The amount of Cash  Consideration  paid to the holder of
Certificates  shall be in the form of a wire transfer of  immediately  available
funds if so requested by any holder  entitled to receive not less than  $500,000
in cash,  and the cost of such wire  transfers  shall be borne by the  Surviving
Corporation.  Such letter of transmittal and instructions  shall be available at
the Closing for holders of American Common Stock. Notwithstanding the foregoing,
neither the  Exchange  Agent nor any party hereto shall be liable to a holder of
shares of American  Common  Stock for any Merger  Consideration  delivered  to a
public official pursuant to applicable  abandoned  property,  escheat or similar
Laws.

         (c)  Promptly  following  the date  which is six (6)  months  after the
Closing Date,  the Exchange  Agent shall deliver to Mergeparty  all cash and any
shares of Tower  Common  Stock in its  possession  relating to the  transactions
described in this  Agreement  that remain  unclaimed,  and the Exchange  Agent's
duties shall terminate.  Thereafter,  each holder of a Certificate may surrender
such  Certificate  to the  Surviving  Corporation  and  (subject  to  applicable
abandoned  property,  escheat and similar Laws) receive in exchange therefor the
aggregate  Merger  Consideration  to which such holder is entitled,  without any
interest thereon, but together with dividends and distributions, if any, paid by
American  Tower on or with respect to the Tower Common Stock in accordance  with
the provisions of Section 3.2(d).

         (d)  Notwithstanding  any  other  provisions  of  this  Agreement,   no
dividends  or other  distributions  declared  after the  earlier to occur of the
Tower Merger Effective Time or the Effective Time on Tower Common Stock shall be
paid  with  respect  to any  shares  of  Tower  Common  Stock  represented  by a
Certificate  until such  Certificate  is  surrendered  for  exchange as provided
herein or, if the Tower Merger  Effective Time shall have occurred,  as provided
in the  Tower  Merger  Agreement.  Subject  to the  effect of  Applicable  Laws,


                                       -4-


<PAGE>


following  surrender of any such Certificate,  there shall be paid to the holder
of the  shares of Tower  Common  Stock  issued  in  exchange  therefor,  without
interest,  (i) at the time of such  surrender,  the amount of dividends or other
distributions  with a record date after the earlier to occur of the Tower Merger
Effective  Time or the Effective Time  theretofore  payable with respect to such
shares of Tower  Common Stock and not paid,  less the amount of any  withholding
taxes which may be required thereon,  and (ii) at the appropriate  payment date,
the amount of  dividends  or other  distributions  with a record  date after the
earlier to occur of the Tower Merger  Effective  Time or the Effective  Time but
prior to surrender  and a payment  date  subsequent  to  surrender  payable with
respect to such shares of Tower Common Stock, less the amount of any withholding
taxes which may be required thereon.

         (e) If the  Merger  Consideration  (or any  portion  thereof)  is to be
delivered  to a Person  other  than the  Person  in whose  name the  Certificate
surrendered in exchange  therefor is registered,  it shall be a condition to the
delivery of the Merger  Consideration  that the Certificate so surrendered shall
be properly endorsed or accompanied by appropriate stock powers (with signatures
guaranteed in accordance  with the  transmittal  letter) and otherwise in proper
form for transfer,  that such  transfer  otherwise be proper and that the Person
requesting  such transfer pay to the Exchange  Agent any transfer or other Taxes
payable by reason of the  foregoing  or  establish  to the  satisfaction  of the
Exchange Agent that such Taxes have been paid or are not required to be paid.

         (f) In the event  any  Certificate  shall  have  been  lost,  stolen or
destroyed,  upon the making of an affidavit of that fact by the Person  claiming
such  Certificate  to be lost,  stolen or  destroyed  and  subject to such other
reasonable conditions as the Exchange Agent may impose, the Exchange Agent shall
issue in exchange  for such lost,  stolen or  destroyed  Certificate  the Merger
Consideration  (to the extent  applicable)  deliverable  in  respect  thereof as
determined in accordance with this Article.  When  authorizing such issue of the
Merger  Consideration  in  exchange  therefor,  the  Exchange  Agent may, in its
discretion  and as a condition  precedent to the issuance  thereof,  require the
owner of such lost, stolen or destroyed  Certificate (if other than a recognized
financial institution) to give the Exchange Agent a bond or other surety in such
sum as it may reasonably  direct as indemnity against any Claim that may be made
against the Exchange Agent with respect to the Certificate  alleged to have been
lost, stolen or destroyed.

         (g) At and after the Effective Time, the holder of a Certificate  shall
cease to have any rights as a holder of shares of American Common Stock,  except
for the right to surrender  Certificates in the manner prescribed by Section 3.2
in  exchange  for  delivery  of the Merger  Consideration,  or, in the case of a
holder of Dissenting  Shares,  the right to perfect the right to receive payment
for Dissenting Shares pursuant to Section 262 of the DCL.

         (h) The  Surviving  Corporation  shall  be  entitled  to,  or  shall be
entitled  to  cause  the  Exchange  Agent  to,  deduct  and  withhold  from  the
consideration  otherwise deliverable pursuant to this Agreement to any holder of
shares of American  Common Stock such amounts as are required to be deducted and
withheld  with  respect to the  making of such  payment  under the Code,  or any
provision of state,  local or foreign Tax Law. To the extent that amounts are so
withheld by the Surviving Corporation or the Exchange Agent, as the case may be,
such  withheld  amounts  shall be treated for all purposes of this  Agreement as
having been  delivered  to the holder of the shares of American  Common Stock in
respect  of which  such  deduction  and  withholding  was made by the  Surviving
Corporation or the Exchange Agent.

         (i) The  Exchange  Agent shall invest any funds held by it for purposes
of this Section 3.2 as directed by  Mergeparty,  on a daily basis.  Any interest
and other income resulting from such investments shall be paid to Mergeparty and
any risk of loss resulting from such investments shall be borne by Mergeparty.


                                       -5-


<PAGE>


         3.3 Closing of American's  Transfer  Books.  At the Effective Time, the
stock  transfer  books of American  relating to American  Common  Stock shall be
closed and no transfer of shares of American Common Stock which were outstanding
immediately  prior to the Effective Time shall thereafter be made. If, after the
Effective  Time,  subject  to  the  terms  and  conditions  of  this  Agreement,
Certificates  formerly  representing  American Common Stock are presented to the
Surviving  Corporation,  they shall be  canceled  and  exchanged  for the Merger
Consideration in accordance with the provisions of this Article.

         3.4 Dissenting Shares.

         (a)  Notwithstanding  any  other  provision  of this  Agreement  to the
contrary, shares of American Common Stock that are outstanding immediately prior
to the Effective Time and which are held by American stockholders who shall have
not voted in favor of the Merger or  consented  thereto in writing and who shall
be entitled to and shall have demanded  properly in writing appraisal rights for
such shares of American  Common Stock in accordance  with Section 262 of the DCL
and who  shall  not have  withdrawn  such  demand or  otherwise  have  forfeited
appraisal rights (collectively, the "Dissenting Shares"), shall not be converted
into or  represent  the right to  receive  the Merger  Consideration  payable in
respect  of each  share of  American  Common  Stock  represented  thereby.  Such
American  stockholders  shall be  entitled to receive  payment of the  appraised
value of such shares of American  Common Stock held by them in  accordance  with
the provisions of the DCL; provided, however, that all Dissenting Shares held by
American  stockholders who shall have failed to perfect or who effectively shall
have withdrawn,  forfeited or lost their  appraisal  rights with respect to such
shares of American  Common Stock under the DCL shall thereupon be deemed to have
been  converted  into and to have become  exchangeable  for, as of the Effective
Time,  the  right  to  receive,   without  any  interest  thereon,   the  Merger
Consideration  upon  surrender,  in the manner  provided in Section  3.2, of the
Certificates with respect to such shares.

         (b) American  shall give  Mergeparty  prompt  notice of any demands for
appraisal  rights  received by it,  withdrawals  of such demands,  and any other
instruments  served  pursuant to the DCL and  received by American  and relating
thereto.   American  shall  give   Mergeparty  the  opportunity  to  direct  all
negotiations  and proceedings with respect to demands for appraisal rights under
the  provisions of the DCL.  American  shall not,  except with the prior written
consent  of  Mergeparty,  make any  payment  with  respect  to any  demands  for
appraisal rights, or offer to settle, or settle, any such demands.

         (c) If the Tower Merger  Effective Time shall not have occurred and the
Delaware  Court of  Chancery  (the  "Court")  conducts an  appraisal  proceeding
pursuant  to  Section  262 of the  DCL  relating  to an  obligation  to pay  the
appraised value per share of American Common Stock  ("Appraised Total Value") to
the holders of the  Dissenting  Shares,  American  Tower shall  promptly  pay to
American  the portion of the  Appraised  Total Value  attributable  to the Tower
Stock  Consideration  (the "Tower Stock Payment") and American shall  contribute
(without the payment of any amount or the issuance of any securities by American
Tower) to the capital of American  Tower such shares of Tower Common Stock owned
by American that the holders of the  Dissenting  Shares would have been entitled
to receive  had they not  exercised  their  appraisal  rights.  The Tower  Stock
Payment shall be determined pursuant to the following provisions:

                  (i) American  shall  request the Court to determine in writing
         the Tower Stock Payment. If the Court shall make such determination the
         Tower Stock Payment shall be the amount so determined; and

                  (ii) If the Court shall not make such  determination  within a
         30-day period  following such request (at which time such request shall
         be withdrawn) (the "Determination Deadline"),  American, American Tower
         and Mergeparty  shall submit to an arbitrator  (the  "Arbitrator")  for
         review 

                                       -6-


<PAGE>

         and  resolution  the  determination  of the Tower  Stock  Payment.  The
         Arbitrator  shall be a nationally  recognized  investment  banking firm
         which shall be agreed upon by American,  Mergeparty  and American Tower
         in writing.  The  Arbitrator  shall be  requested  to render a decision
         resolving  the  amount  of the  Tower  Stock  Payment  within  30  days
         following the date of its selection. If the parties cannot agree on the
         firm  to be  selected  as  Arbitrator  within  15  days  following  the
         Determination Deadline, then American and Mergeparty,  on the one hand,
         and American Tower, on the other hand,  shall each choose one such firm
         within  10 days  following  the  expiration  of such  15-day  period to
         review,  resolve  and agree on the  determination  of the  Tower  Stock
         Payment,  which  determination,  once agreed to in writing by both such
         firms, shall be final,  conclusive and binding on the parties.  If such
         two firms cannot agree on the amount of the Tower Stock Payment  within
         30 days  following  the  date on  which  the  second  of such  firms is
         selected,  then such two firms shall promptly  select a third such firm
         to make such  determination,  which determination shall be made by such
         third  firm  within  30 days of the date on which  such  third  firm is
         selected.  The  determination  of such  third firm of the amount of the
         Tower  Stock  Payment  shall be final,  conclusive  and  binding on the
         parties.  The cost of any such  arbitration  (including the fees of the
         Arbitrator and any other firm selected hereunder) shall be borne 50% by
         American and 50% by American  Tower.  American Tower shall promptly pay
         to American  the amount of the Tower Stock  Payment once such amount is
         determined in accordance with this clause (ii).

         3.5  Tower  Merger.   Anything  in  this   Agreement  to  the  contrary
notwithstanding,  if the Effective  Time shall not have occurred by May 31, 1998
(as  such  date  may be  extended  by  American  with  the  written  consent  of
Mergeparty,   such  consent  not  to  be  unreasonably   withheld,   delayed  or
conditioned),  on June 1, 1998 (or the date following the date, if any, to which
the May 31, 1998 date shall have been so  extended),  the Board of  Directors of
American shall, in its sole discretion,  either (i) consummate the merger of ATS
Merger  Corporation,  a Delaware  corporation  and a wholly-owned  subsidiary of
American ("ATS Mergercorp"), with and into American, which will be the surviving
corporation (the "Tower  Merger"),  pursuant to the agreement and plan of merger
between American and ATS Mergercorp dated as of the date hereof and set forth as
Exhibit D hereto (the "Tower Merger  Agreement"),  or (ii) irrevocably  elect to
abandon the Tower Merger. Pursuant to the Tower Merger Agreement,  each share of
ATS  Mergercorp  Common Stock issued and  outstanding  immediately  prior to the
effective time of the Tower Merger (the "Tower Merger Effective Time") shall, by
virtue of the Tower  Merger  and  without  any  action on the part of the holder
thereof,  be automatically  canceled and extinguished and each share of American
Common  Stock  issued  and  outstanding  immediately  prior to the Tower  Merger
Effective Time shall be converted into the right to receive:

                  (a) one share of Tower  Common  Stock,  with (i) each share of
         American  Class A Common being  converted into the right to receive one
         share of Tower  Class A Common,  (ii) each  share of  American  Class B
         Common  being  converted  into the right to receive  one share of Tower
         Class B Common,  and (iii) each share of American  Class C Common being
         converted  into the right to receive  one share of Tower Class C Common
         (collectively, the "Tower Merger Tower Consideration"); and

                  (b) a fraction (the "American Conversion Fraction") of a share
         of  American  Common  Stock of the same class as the class of  American
         Common  Stock  being  converted,  (i) the  numerator  of  which  is the
         difference between (A) the denominator and (B) the value (determined as
         set forth below) of one share of Tower Class A Common immediately prior
         to the Tower Merger  Effective  Time, and (ii) the denominator of which
         is the value  (determined  as set forth below) of one share of American
         Class A Common  immediately  prior to the Tower Merger  Effective  Time
         (collectively  with the Tower  Merger Tower  Consideration,  the "Tower
         Merger Consideration").



                                       -7-


<PAGE>


For purposes of  determining  the value of the  American  Class A Common and the
Tower Class A Common  immediately  prior to the Tower Merger  Effective Time the
following principles shall apply:

                  (x) each share of American  Class A Common  shall be valued at
         an amount  equal to the average  closing  sales  price of the  American
         Class A Common on the NYSE, as reported by the Wall Street Journal, for
         the ten (10) consecutive trading days immediately  preceding the second
         trading date prior to the Tower Merger Effective Time; and

                  (y) each share of Tower Class A Common  shall be valued at the
         amount  determined  in  good  faith  by the  American  Radio  Board  of
         Directors  to be its fair market value  immediately  prior to the Tower
         Merger Effective Time.

No certificates  in respect of fractional  shares of American Common Stock shall
be  issued  in the  Tower  Merger,  and cash  shall be paid in lieu  thereof  as
provided in the Tower Merger Agreement.  The certificates that immediately prior
to the Tower Merger  Effective Time represented  outstanding  shares of American
Common  Stock shall be deemed,  without any action of the  holders  thereof,  to
represent that number of shares of American Common Stock that the holder thereof
has the right to receive  pursuant to clause 3.5(b),  together with cash in lieu
of fractional shares as provided in the Tower Merger Agreement.

         Immediately  prior to the Tower Merger  Effective Time,  American shall
contribute  to ATS  Mergercorp a number of shares of Tower Common Stock equal to
the Tower Merger Tower Consideration.


                                    ARTICLE 4

                   REPRESENTATIONS AND WARRANTIES OF AMERICAN

         Except  as  set  forth   with   respect  to   specifically   identified
representations  and  warranties  in  the  American  Disclosure  Schedule  or as
otherwise  contemplated  by  this  Agreement,  American  hereby  represents  and
warrants to Mergeparty and Mergeparty Subsidiary as follows:

         4.1  Organization  and  Business;   Power  and  Authority;   Effect  of
Transaction.

         (a) American is a corporation duly  incorporated,  validly existing and
in good  standing  under the laws of the State of Delaware and has all requisite
power  and  authority  (corporate  and  other)  to own or hold  under  lease its
properties  and to  conduct  its  business  as now  conducted  and as  presently
proposed to be conducted.  American is duly  qualified and in good standing as a
foreign  corporation in each other  jurisdiction  (as shown on Section 4.1(a) of
the American  Disclosure  Schedule) in which the character of the property owned
or leased by it or the  nature  of its  business  or  operations  requires  such
qualification,  with full power and authority  (corporate and other) to carry on
the  business in which it is  engaged,  except in such  jurisdictions  where the
failure  to  be so  qualified  or  in  good  standing,  individually  or in  the
aggregate,  is not  reasonably  likely  to have a  Material  Adverse  Effect  on
American.

         (b) Each of American and its  Subsidiaries  has all requisite power and
authority (corporate and other) to execute,  deliver and perform its obligations
under this  Agreement and each  Collateral  Document  executed or required to be
executed by such party  pursuant  hereto or thereto and to consummate the Merger
and the other transactions  contemplated hereby and thereby,  and the execution,
delivery and performance of this Agreement and each Collateral Document executed
or required to be executed  pursuant hereto or thereto have been duly authorized
by all  requisite  corporate  or other  action on the part of  American  and its

                                       -8-


<PAGE>


Subsidiaries,  other than the  approval  of the  holders  of shares of  American
Common Stock contemplated by Section 4.13, and no other corporate proceedings on
the part of American or any of its  Subsidiaries are necessary to authorize this
Agreement or the transactions contemplated hereby or to consummate the Merger or
the other transactions so contemplated  (other than, with respect to the Merger,
the Required  Vote and with  respect to the Tower  Merger,  the  Required  Tower
Vote).  This  Agreement  has been duly  executed  and  delivered by American and
constitutes, and each Collateral Document executed or required to be executed by
American and its  Subsidiaries  pursuant hereto or to consummate the Merger when
executed and delivered by American and its  Subsidiaries,  as  applicable,  will
constitute, a valid and binding obligation of American and its Subsidiaries,  as
applicable,  enforceable in accordance with their  respective  terms,  except as
such  enforceability  may be limited by bankruptcy,  moratorium,  insolvency and
similar laws  affecting the rights and remedies of creditors and  obligations of
debtors  generally and by general  principles of equity.  As of the date hereof,
the Board of Directors of American, at a meeting duly called and held at which a
quorum was present throughout,  has approved the Merger and this Agreement,  and
the Tower Merger and the Tower Merger  Agreement,  and has recommended  that the
holders of shares of American Common Stock approve and adopt this Agreement, the
Tower Merger  Agreement and the  transactions  contemplated  hereby and thereby,
including without limitation the Merger and the Tower Merger.

         (c)  The  execution,  delivery  and  performance  by  American  and its
Subsidiaries,  as  applicable,  of this  Agreement and any  Collateral  Document
executed or required to be executed by such parties  pursuant  hereto or thereto
do  not,  and  the  consummation  by  American  of  the  Merger  and  the  other
transactions  contemplated  hereby and thereby,  and compliance  with the terms,
conditions and provisions hereof or thereof by such parties will not:

                  (i) (A) Except as set forth in Section  4.1(c) of the American
         Disclosure Schedule,  conflict with, or result in a breach or violation
         of, or constitute a default under,  any Organic Document of American or
         its Subsidiaries,  as applicable,  or (B) conflict with, or result in a
         breach or violation  of, or constitute a default  under,  or permit the
         termination,   cancellation   or  acceleration  of  any  obligation  or
         liability  in, or but for any  requirement  of the  giving of notice or
         passage of time or both would  constitute such a conflict with,  breach
         or  violation  of, or default  under,  or permit any such  termination,
         cancellation or acceleration of, any agreement, arrangement,  contract,
         undertaking,  understanding,  Applicable  Law or  other  obligation  or
         Private  Authorization of American or its Subsidiaries,  as applicable,
         except,  in the  case of  clause  (B),  for such  conflicts,  breaches,
         violations, terminations, cancellations, defaults or accelerations that
         would not,  individually or in the aggregate,  be reasonably  likely to
         have a Material Adverse Effect on American; or

                  (ii)  result in or permit the  creation or  imposition  of any
         Lien upon any property now owned or leased by American  except for such
         Liens that would not,  individually or in the aggregate,  be reasonably
         likely to have a Material Adverse Effect on American; or

                  (iii) require any  Governmental  Authorization or Governmental
         Filing  except  for  (A)  the  FCC  Consents,  (B)  filings  under  the
         Hart-Scott-Rodino  Act, (C) the filing with the  Commission  of (I) the
         Proxy Statement, (II) the Tower Proxy Statement, (III) the Registration
         Statement  and (IV) such reports  under  Section  13(a) or 15(d) of the
         Exchange Act as may be required in connection  with this  Agreement and
         the transactions  contemplated by this Agreement, (D) the filing of the
         Certificate of Merger and a certificate of merger relating to the Tower
         Merger with the Delaware  Secretary of State and appropriate  documents
         with the  relevant  authorities  of other  states in which  American is
         qualified to do business and (E) such other Governmental Authorizations
         and  Governmental  Filings  the failure of which to be made or obtained
         would not be  individually  or in the aggregate,  reasonably  likely to
         have a Material Adverse Effect on American.


                                       -9-


<PAGE>


         (d) American  does not have any direct or indirect  Subsidiaries  other
than those set forth on Section 4.1(d) of the American Disclosure Schedule (read
without  the last  three  lines of the first page  thereof)  (and other than ATS
Mergercorp,  American  Tower,  American  Tower  Systems  (Delaware),  Inc.,  ATS
Needham,  LLC, Tower, LLC and  Communications  Systems  Development,  LLC). Each
direct or  indirect  Subsidiary  of  American  (and other  than ATS  Mergercorp,
American  Tower,  American Tower Systems  (Delaware),  Inc.,  ATS Needham,  LLC,
Tower,  LLC and  Communications  Systems  Development,  LLC) is (i) wholly-owned
unless noted  otherwise in Section 4.1(d) of the American  Disclosure  Schedule,
(ii) a  corporation  which  is  duly  organized,  validly  existing  and in good
standing  under  the laws of the  respective  state of  incorporation  set forth
opposite its name on Section  4.1(d) of the American  Disclosure  Schedule,  and
(iii) duly qualified and in good standing as a foreign corporation in each other
jurisdiction (as shown on Section 4.1(d) of the American Disclosure Schedule) in
which the  character of the property  owned or leased by it or the nature of its
business  or  operations  requires  such  qualification,  with  full  power  and
authority (corporate and other) to carry on the business in which it is engaged,
except where the failure to be so qualified or in good standing, individually or
in the  aggregate,  would not be  reasonably  likely to have a Material  Adverse
Effect  on  American.   American  owns,  directly  or  indirectly,  all  of  the
outstanding  capital stock and equity  interests (as shown in Section  4.1(d) of
the American  Disclosure  Schedule) of such Subsidiaries,  free and clear of all
Liens  (except  as set forth in the  American  Financial  Statements  or Section
4.1(d) of the American  Disclosure  Schedule),  and all such stock has been duly
authorized and validly issued and is fully paid and nonassessable.  There are no
outstanding  Option  Securities  or  Convertible  Securities,  or  agreements or
understandings of any nature whatsoever, relating to the authorized and unissued
or outstanding  capital stock of such  Subsidiaries  (except as set forth in the
American  Financial  Statements  or Section  4.1(d) of the  American  Disclosure
Schedule.

         (e) Each of ATS  Mergercorp  and American  Tower is (i) a  wholly-owned
subsidiary  of American (in the case of American  Tower,  as of the date hereof)
and (ii) a corporation  which is duly  organized,  validly  existing and in good
standing  under the DCL.  American  owns,  directly  or  indirectly,  all of the
outstanding  capital stock and equity  interests of each of ATS  Mergercorp  and
American  Tower,  free  and  clear  of all  Liens,  subject,  in the case of ATS
Mergercorp,  to the receipt of Amendment No. 2 to American's  Credit  Agreements
referred to in Section  4.1(d) of the American  Disclosure  Schedule,  a copy of
which has been  delivered to Mergeparty  prior to the date hereof,  and all such
stock  has  been  duly  authorized  and  validly  issued,   is  fully  paid  and
nonassessable and is not subject to any preemptive or similar rights.  There are
no outstanding  Option  Securities or Convertible  Securities,  or agreements or
understandings of any nature whatsoever, relating to the authorized and unissued
outstanding capital stock of such Subsidiaries (except, with respect to American
Tower, pursuant to the following: (i) the Agreement and Plan of Merger, dated as
of December 12, 1997 (the "ATC Merger Agreement"), by and between American Tower
and American Tower Corporation,  an unaffiliated Delaware corporation, a copy of
which  has been  delivered  to  Mergeparty  prior to the date  hereof,  (ii) the
Agreement  and Plan of  Merger,  dated as of  November  21,  1997,  by and among
American Tower, American Tower Systems (Delaware), Inc., Gearon & Co., Inc., and
J. Michael Gearon,  Jr., a copy of which has been delivered to Mergeparty  prior
to the date hereof,  (iii) the proposed issue and sale of shares of Tower Common
Stock to certain officers and directors of American Tower (and their affiliates)
for an aggregate consideration of approximately $80,000,000, (iv) employee stock
options  outstanding to purchase  shares of American  Tower Systems  (Delaware),
Inc. which will be converted into options to acquire Tower Common Stock, and (v)
as  contemplated  by Section  6.8(b)).  The authorized  capital stock of (i) ATS
Mergercorp  consists of 3,000 shares of common  stock,  par value $.01 per share
(the "ATS  Mergercorp  Common  Stock"),  and (ii)  American  Tower  consists  of
20,000,000  shares of  preferred  stock,  200,000,000  shares  of Tower  Class A
Common,  50,000,000  shares of Tower Class B Common,  and  10,000,000  shares of
Tower Class C Common, and the terms of the Restated Certificate of Incorporation
of American Tower, a copy of which has been delivered to Mergeparty prior to the
date hereof, relating to each of the shares of Tower Class A Common, 

                                      -10-


<PAGE>


Tower Class B Common and Tower Class C Common (other than those  relating to the
number  of  authorized  shares)  are  identical  to the  terms  of the  Restated
Certificate  of  Incorporation  of  American  as in  effect  on the  date of the
Original  Merger  Agreement  relating to the shares of American  Class A Common,
American  Class B Common and American Class C Common,  respectively,  except for
the following terms: (i) terms which permit dividends and other distributions of
securities of Persons  other than  American  Tower  (including  Subsidiaries  of
American  Tower) to be made in the form of different  classes of  securities  of
such  Persons,  (ii) terms which  provide that if a holder of Tower Common Stock
grants a proxy,  whether  revocable  or  irrevocable,  and  whether  general  or
specific  to a  particular  transaction,  the  granting  of such  proxy does not
constitute  a transfer for  purposes of  requiring  conversion  of Tower Class B
Common to Tower  Class A Common,  (iii)  terms  which  permit any CEA Holder (as
defined in the  Restated  Certificate  of  Incorporation  of American  Tower) to
convert shares of Tower Class C Common Stock into shares of Tower Class A Common
Stock upon approval of the Board of Directors of American Tower,  and (iv) terms
clarifying the fact that holders of Tower Class A Common Stock and Tower Class B
Common Stock vote as a single class on all matters  submitted  for a stockholder
vote, including,  notwithstanding the first sentence of Section 242(b)(2) of the
DCL, any  amendment of the Restated  Certificate  of  Incorporation  of American
Tower which would  increase or decrease the number of  authorized  shares of any
class of Tower Common  Stock.  The number of shares of American  Tower which are
authorized  and  outstanding  and owned by  American  is equal to the  number of
authorized  and  outstanding  shares of American  Common Stock and the number of
shares of American Common Stock issuable upon the exercise of Option  Securities
and upon the conversion of Convertible Securities (except with respect to shares
of  American  Common  Stock  subject to  American  Options set forth on Schedule
4.1(e) to this Agreement  which are held by Tower Employees who have stated that
they will enter into definitive agreements to have such American Options assumed
by American  Tower and  converted  into options to acquire Tower Common Stock in
accordance with Section 6.8(b)).

         4.2 Financial and Other Information.  American has heretofore furnished
to  Mergeparty  copies  of the  audited  consolidated  financial  statements  of
American and its  Subsidiaries  set forth in its Annual Report on Form 10-K (the
"American  10-K") for the fiscal year ended  December 31, 1996 and the unaudited
consolidated  financial statements of American and its Subsidiaries set forth in
its Quarterly Report on Form 10-Q for the fiscal quarter ended June 30, 1997 and
its Quarterly  Report on Form 10-Q for the fiscal  quarter  ended  September 30,
1997 (the "American  September  10-Q")  (collectively,  the "American  Financial
Statements").  The  American  Financial  Statements,  including in each case the
notes  thereto,  comply as to form, in all material  respects,  with  applicable
accounting   requirements  and  the  published  rules  and  regulations  of  the
Commission  with respect  thereto,  have been prepared in  accordance  with GAAP
applied on a consistent basis throughout the periods covered thereby,  except as
otherwise  noted  therein,  and fairly  present  in all  material  respects  the
financial  condition,  results of operations  and cash flows of American and its
Subsidiaries  on the bases therein stated,  as of the respective  dates thereof,
and for the respective periods covered thereby subject, in the case of unaudited
financial  statements,  to  normal  year-end  audit  adjustments  and  accruals.
American has filed all required  reports and other documents with the Commission
since July 1, 1995 (the  "American SEC  Documents").  Except as set forth in the
American SEC  Documents  filed and publicly  available  prior to the date of the
Original Merger Agreement (the "Filed American SEC Documents"), neither American
nor any of its  Subsidiaries  has any  liabilities  or obligations of any nature
(whether accrued,  absolute,  contingent or otherwise) which, individually or in
the aggregate,  would be reasonably  likely to have a Material Adverse Effect on
American. None of the American Disclosure Schedule or the American SEC Documents
contains or will  contain any untrue  statement  of a material  fact or omits or
will omit to state a material  fact  required to be stated  herein or therein or
necessary in order to make the statements  contained herein or therein, in light
of the circumstances under which they were made, not misleading.



                                      -11-


<PAGE>


         4.3  Changes in  Condition.  Except as set forth in Section  4.3 of the
American Disclosure Schedule, between June 30, 1997 and the date of the Original
Merger Agreement, there has been no Material Adverse Change in American.

         4.4 Properties.  (a) American and each of its Subsidiaries  (other than
the Tower Subsidiaries) has good and marketable title to all material parcels of
real property owned by it and good and merchantable  title to all material items
of property and assets, tangible and intangible,  (i) reflected in the financial
statements  of American as of June 30, 1997,  and (ii)  acquired  after June 30,
1997, except in each case for those sold or otherwise disposed of since June 30,
1997, in each case free and clear of all Liens,  except (x) Permitted  Liens and
(y) Liens set forth in the American  Financial  Statements or Section 4.4 of the
American Disclosure Schedule.

         (b) All of the assets of American and its Subsidiaries  material to the
continued  operation  of  their  respective  businesses  are in  good  operating
condition,  reasonable wear and tear excepted, and usable in the ordinary course
of business, except where the failure to be in such condition or so usable would
not,  individually or in the aggregate,  be reasonably likely to have a Material
Adverse Effect on American.

         4.5 Compliance  with Private  Authorizations.  American and each of its
Subsidiaries  (other  than the Tower  Subsidiaries)  has  obtained  all  Private
Authorizations  which are  necessary for the ownership and operation by American
or its Subsidiaries of the business of American and its Subsidiaries, taken as a
whole,  and the conduct of business  thereof as now conducted and which,  if not
obtained and maintained,  would, individually or in the aggregate, be reasonably
likely  to  have a  Material  Adverse  Effect  on  American.  All  such  Private
Authorizations  are, to  American's  knowledge,  in full force and  effect,  and
neither American nor any of its Subsidiaries (other than the Tower Subsidiaries)
is, to  American's  knowledge,  in breach or violation  of, or in default in the
performance,  observance or fulfillment of, any such Private Authorization, and,
to American's knowledge, no Event exists or has occurred, which constitutes,  or
but for any requirement of the giving of notice or passage of time or both would
constitute,  such a  breach,  violation  or  default,  under  any  such  Private
Authorization,  except for such  defaults,  breaches or violations as would not,
individually  or in the  aggregate,  be  reasonably  likely  to have a  Material
Adverse Effect on American.

         4.6 Compliance  with  Governmental  Authorizations  and Applicable Law;
Litigation.

         (a) Section 4.6(a) of the American  Disclosure Schedule contains a list
of each material  Governmental  Authorization  (including without limitation all
material  American  FCC  Licenses)  required  under  Applicable  Laws to own and
operate  the  business of American  and its  Subsidiaries  (other than the Tower
Subsidiaries),  including without limitation each of the American  Stations,  as
currently operated,  all of which are in full force and effect,  subject to such
qualifications  and  exceptions  as may be set  forth in  Section  4.6(a) of the
American  Disclosure  Schedule.  Certain of the  Subsidiaries of American (other
than any of the Tower  Subsidiaries)  are the  authorized  legal  holders of the
American  FCC  Licenses  listed in  Section  4.6(a) of the  American  Disclosure
Schedule,  none of which is subject to any  restriction or condition which would
limit in any material respect the operations of any of the American  Stations as
currently conducted except as noted in Section 4.6(a) of the American Disclosure
Schedule.  The American FCC  Licenses  listed in Section  4.6(a) of the American
Disclosure  Schedule are valid and in full force and effect and are not impaired
in any  material  respect  by any  act or  omission  of  American  or any of its
Subsidiaries,  subject to such qualifications and exceptions as may be set forth
in Section 4.6(a) of the American Disclosure Schedule; and the operation of each
of the American Stations is in accordance with such American FCC Licenses in all
material respects,  except to the extent so listed in Sections 4.6(a) and (b) of
the  American  Disclosure  Schedule.  American  is  fully  qualified  to be  the
transferor of control of the American FCC Licenses.  All material reports, forms
and statements  required to be filed by American or any of its Subsidiaries with
the FCC with  respect to each of 

                                      -12-


<PAGE>


the American Stations have been filed and are true, complete and accurate in all
material  respects.  American or one of its  Subsidiaries  (other than the Tower
Subsidiaries)  has obtained all Governmental  Authorizations  in addition to the
American  FCC  Licenses  listed in  Section  4.6(a) of the  American  Disclosure
Schedule  which are  necessary for the ownership or operations or the conduct of
the business of American  and its  Subsidiaries,  taken as a whole  (except with
respect to the American Brokered  Stations),  as now conducted and which, if not
obtained and maintained,  would, individually or in the aggregate, be reasonably
likely to have a Material Adverse Effect on American and American's  performance
with respect thereto,  and the operation of the American Brokered Stations is in
accordance  with all  applicable  Governmental  Authorizations  except where the
failure to be so in accordance would not be reasonably likely to have a Material
Adverse  Effect on American.  As of the date of the Original  Merger  Agreement,
except  as noted in  Section  4.6(a) of the  American  Disclosure  Schedule,  no
application,  action or  proceeding  is  pending  for the  renewal  or  material
modification  of any of the American FCC Licenses and, to American's  knowledge,
except as noted in Section 4.6(b) of the American Disclosure Schedule, there was
not as of the date of the Original Merger  Agreement before the FCC any material
investigation, proceeding, notice of violation, order of forfeiture or complaint
against  American or any of its  Subsidiaries  relating  to any of the  American
Stations or other FCC licensed  facilities that, if adversely decided,  would be
reasonably  likely to have a Material  Adverse Effect on American (and as of the
date of the Original  Merger  Agreement  American did not have  knowledge of any
basis that would cause the FCC not to renew any of the American  FCC  Licenses).
Except as noted in Schedule 4.6(b) of the American  Disclosure  Schedule,  as of
the date of the Original  Merger  Agreement,  there was not then pending and, to
American's knowledge,  there was not threatened, any action by or before the FCC
to revoke, suspend, cancel, rescind or modify in any material respect any of the
American FCC Licenses that, if adversely decided,  would be reasonably likely to
have a Material  Adverse Effect on American (other than proceedings to amend FCC
rules of general applicability to the radio industry).

         (b) Except as otherwise specifically set forth in Section 4.6(b) of the
American  Disclosure   Schedule,   since  January  1,  1996,  American  and  its
Subsidiaries  (other than the Tower Subsidiaries) have conducted its and each of
their  respective  businesses  and  owned  and  operated  its and  each of their
respective   properties  in  accordance  with  all  Applicable  Laws  (excluding
Environmental Laws) and Governmental  Authorizations,  except for such breaches,
violations and defaults as,  individually or in the aggregate,  have not had and
are not reasonably likely to have a Material Adverse Effect on American.  Except
as otherwise specifically described in Section 4.6(b) of the American Disclosure
Schedule and except with respect to Environmental Laws, neither American nor any
of its Subsidiaries is in or is charged in writing by any Authority with, or, to
American's knowledge, is threatened or under investigation by any Authority with
respect  to,  any  breach  or  violation  of,  or  default  in the  performance,
observance or  fulfillment  of, any Applicable Law relating to the ownership and
operation  of  American's  and its  Subsidiaries'  properties  or the conduct of
American's and its  Subsidiaries'  business which will,  individually  or in the
aggregate,  be reasonably  likely to have a Material Adverse Effect on American.
Except as otherwise  specifically  described  in Section  4.6(b) of the American
Disclosure  Schedule and except with  respect to  Environmental  Laws,  no Event
exists or has occurred, which constitutes,  or but for any requirement of giving
of notice or passage of time or both would constitute,  such a breach, violation
or default,  under any Governmental  Authorization or any Applicable Law, except
for such breaches,  violations or defaults as, individually or in the aggregate,
have not had and  would not be  reasonably  likely  to have a  Material  Adverse
Effect on American.  With respect to matters, if any, of a nature referred to in
Section  4.6(b)  of  the  American  Disclosure  Schedule,  except  as  otherwise
specifically  described in Section 4.6(b) of the American  Disclosure  Schedule,
all such information and matters set forth in the American Disclosure  Schedule,
if adversely  determined against American or one of its Subsidiaries (other than
the  Tower  Subsidiaries),  individually  or in  the  aggregate,  would  not  be
reasonably likely to have a Material Adverse Effect on American.


                                      -13-


<PAGE>


         (c) Except as  disclosed  in the Filed  American  SEC  Documents  or in
Section 4.6(c) of the American Disclosure  Schedule,  there are no Legal Actions
pending  or, to the  knowledge  of  American,  threatened  against or  affecting
American  or  any  of its  Subsidiaries  (other  than  the  Tower  Subsidiaries)
including any action by or before the FCC to revoke, suspend, cancel, rescind or
modify in any  material  respect any of the American  FCC  Licenses,  except for
Legal Actions that,  individually  or in the aggregate,  would not be reasonably
likely to have a Material Adverse Effect on American.

         4.7  Related  Transactions.  Except as set forth in Section  4.7 of the
American  Disclosure  Schedule,  as  contemplated  herein or as disclosed in the
Filed American SEC Documents, no director, officer, Affiliate or "associate" (as
such term is defined in Rule 12b-2 under the Exchange Act) of American or any of
its Subsidiaries is currently a party to any transaction which would be required
to be disclosed under Item 404 of Regulation S-K of the Securities Act.

         4.8 Taxes and Tax  Matters.  Except as  provided  in Section 4.8 of the
American Disclosure Schedule:

                  (a)  American  has  filed  completely  and  correctly  in  all
         material  respects all Tax Returns which are required by all Applicable
         Laws to be filed by it, and has paid,  or made  adequate  provision for
         the  payment  of, all  material  Taxes which have or may become due and
         payable pursuant to said Tax Returns and all other Taxes,  governmental
         charges and  assessments  received to date other than those Taxes being
         contested in good faith for which  adequate  provision has been made on
         the most recent  balance sheet  forming part of the American  Financial
         Statements.  The Tax Returns of  American  have been  prepared,  in all
         material respects, in accordance with all Applicable Laws and generally
         accepted principles applicable to taxation consistently applied;

                  (b) all  material  Taxes which  American is required by law to
         withhold and collect have been duly  withheld and  collected,  and have
         been paid over, in a timely manner, to the proper Taxing Authorities to
         the extent due and payable;

                  (c)  American  has not  executed  any  waiver  to  extend,  or
         otherwise taken or failed to take any action that would have the effect
         of extending,  the applicable  statute of limitations in respect of any
         Tax liabilities of American for the fiscal years prior to and including
         the most recent fiscal year;

                  (d)  American  is not a  "consenting  corporation"  within the
         meaning of Section  341(f) of the Code.  American has at all times been
         taxable as a Subchapter C corporation under the Code;

                  (e) American has never been a member of any consolidated group
         (other  than with  American  and its  Subsidiaries)  for Tax  purposes.
         American is not a party to any tax sharing  agreement  or  arrangement,
         other than with its Subsidiaries;

                  (f) no Liens for Taxes exist with respect to any of the assets
         or properties of American, except for statutory Liens for Taxes not yet
         due or payable or that are being contested in good faith;

                  (g) all of the U.S.  Federal income Tax Returns filed by or on
         behalf of each of American and its  Subsidiaries  have been examined by
         and  settled  with the  Internal  Revenue  Service,  or the  statute of
         limitations with respect to the relevant Tax liability expired, for all
         taxable  periods through and including the period ending on the date on
         which the Effective Time occurs;

                  (h) all Taxes due with  respect to any  completed  and settled
         audit,  examination or deficiency  litigation with any Taxing Authority
         have been paid in full;

  

                                      -14-


<PAGE>


                  (i)  there is no  audit,  examination,  deficiency,  or refund
         litigation  pending with respect to any Taxes and during the past three
         years no Taxing  Authority has given written notice of the commencement
         of any audit, examination or deficiency litigation, with respect to any
         Taxes;

                  (j) American is not bound by any currently  effective  private
         ruling,   closing  agreement  or  similar  agreement  with  any  Taxing
         Authority relating to a material amount of Taxes;

                  (k) except with  respect to  like-kind  exchanges  pursuant to
         Section 1031 of the Code,  American shall not be required to include in
         a taxable  period ending after the Effective  Time,  any taxable income
         attributable  to income that  economically  accrued in a prior  taxable
         period as a result of Section 481 of the Code, the  installment  method
         of accounting or any comparable provision of state or local Tax law;

                  (l) (A) no  material  amount of  property  of American is "tax
         exempt  property" within the meaning of Section 168(h) of the Code, (B)
         no  material  amount of assets of  American is subject to a lease under
         Section  7701(h) of the Code,  and (C)  American  is not a party to any
         material  lease made  pursuant  to Section  168(f)(8)  of the  Internal
         Revenue  Code of 1954,  as amended  and in effect  prior to the date of
         enactment of the Tax Equity and Fiscal Responsibility Act of 1982; and

                  (m) immediately  following the Merger,  American will not have
         any  material  amount of income  or gain that has been  deferred  under
         Treasury  Regulation  Section  1.1502-13,  or any material  excess loss
         account in a Subsidiary under Treasury Regulation Section 1.1502-19.

         4.9 Employee Retirement Income Security Act of 1974.

         (a) American  (which for purposes of this Section 4.9 shall include any
ERISA Affiliate) currently sponsors, maintains and contributes only to the Plans
and Benefit  Arrangements set forth in Section 4.9(a) of the American Disclosure
Schedule.  American has delivered or made available to Mergeparty true, complete
and correct copies of (1) each Plan and Benefit  Arrangement (or, in the case of
any unwritten Plans or Benefit Arrangements,  reasonable  descriptions thereof),
(2) the two most recent annual reports on Form 5500 (including all schedules and
attachments  thereto)  filed with the Internal  Revenue  Service with respect to
each Plan (if any such report was  required  by  Applicable  Law),  (3) the most
recent summary plan  description  (or similar  document) for each Plan for which
such a summary plan  description  is required by Applicable Law or was otherwise
provided to plan  participants or beneficiaries and (4) each trust agreement and
insurance or annuity contract or other funding or financing arrangement relating
to any Plan.  To the  knowledge of  American,  each such Form 5500 and each such
summary plan description (or similar  document) does not, as of the date hereof,
contain any material misstatements. Except as set forth in Section 4.9(a) of the
American Disclosure Schedule, as to all Plans and Benefit Arrangements listed in
Section 4.9(a) of the American Disclosure Schedule:

                  (i) all such Plans and  Benefit  Arrangements  comply and have
         been  administered  in form and in operation in  accordance  with their
         respective  terms,  and  with  all  Applicable  Laws,  in all  material
         respects,  and American has not received any notice from any  Authority
         disputing or investigating such compliance;

                  (ii) all such Plans  maintained  by American that are intended
         to comply with  Sections 401 and 501 of the Code comply in all material
         respects with all  applicable  requirements  of such  sections,  and no
         Event has occurred  which is known to American  which will give rise to
         disqualification of any such Plan under such sections or to a tax under
         Section  511 of the Code and each such Plan has been 

                                      -15-


<PAGE>

         the subject of a determination letter from the Internal Revenue Service
         to the effect that such Plan and related  trust is qualified and exempt
         from   Federal   income  Taxes  under   Sections   401(a)  and  501(a),
         respectively,  of the  Code;  no such  determination  letter  has  been
         revoked,  and, to the  knowledge of American,  revocation  has not been
         threatened.  American has  delivered or made  available to Mergeparty a
         copy of the most recent  determination  letter received with respect to
         each Plan for which such a letter has been issued, as well as a copy of
         any pending application for a determination  letter.  American has also
         provided or made available to Mergeparty a list of all Plan  amendments
         as to which a favorable determination letter has not yet been received;

                  (iii)  none of the  assets  of any such Plan are  invested  in
         employer securities or employer real property;

                  (iv)  there are no  Claims  (other  than  routine  Claims  for
         benefits  or  actions  seeking  qualified  domestic  relations  orders)
         pending or, to American's knowledge, threatened involving such Plans or
         the assets of such Plans, and, to American's knowledge,  no facts exist
         which are reasonably likely to give rise to any such Claims (other than
         routine  Claims for  benefits  or actions  seeking  qualified  domestic
         relations orders);

                  (v) no such Plan is subject to Title IV of ERISA, and American
         has no actual or potential liability thereunder;

                  (vi) all group health Plans of American  have been operated in
         compliance  in  all  material  respects  with  the  group  health  plan
         continuation coverage requirements of COBRA;

                  (vii)  neither  American  nor,  to its  knowledge,  any of its
         directors, officers, employees or any other fiduciary has committed any
         breach of  fiduciary  responsibility  imposed  by ERISA or any  similar
         Applicable  Law that would  subject  American or any of its  respective
         directors,  officers  or  employees  to  liability  under  ERISA or any
         similar Applicable Law;

                  (viii)  American  is not and  never  has  been a party  to any
         Multiemployer Plan or made contributions to any such Plan;

                  (ix) except as set forth in the American Financial  Statements
         and pursuant to the provisions of COBRA, American does not maintain any
         Plan  that  provides  for  post-retirement  medical  or life  insurance
         benefits,  and American does not have any  obligation or liability with
         respect to any such Plan  previously  maintained  by it,  except as the
         provisions  of COBRA may apply to any former  employees  or retirees of
         American;

                  (x) all material contributions to, and material payments from,
         the Plans and Benefit  Arrangements  that may have been  required to be
         made  in   accordance   with  the  terms  of  the  Plans  and   Benefit
         Arrangements,  and any applicable collective bargaining agreement, have
         been made. All such  contributions to, and payments from, the Plans and
         Benefit  Arrangements,  except  those  payments to be made from a trust
         qualified  under  Section  401(a) of the Code,  for any  period  ending
         before the Closing Date that are not yet,  but will be,  required to be
         made,  will be properly  accrued and  reflected in the Closing  Balance
         Sheet;

                  (xi) (1) no  "prohibited  transaction"  (as defined in Section
         4975 of the Code or Section 406 of ERISA) has  occurred  that  involves
         the assets of any Plan; (2) no prohibited transaction has occurred that
         could subject American,  any of its employees,  or, to the knowledge of
         American,  a trustee,  administrator  or other  fiduciary  of any trust
         created   under  any  Plan  to  the  tax  or  sanctions  on 

                                      -16-


<PAGE>

         prohibited  transactions imposed by Section 4975 of the Code or Title I
         of ERISA; (3) none of American,  any of its ERISA Affiliates or, to the
         knowledge of American, any trustee, administrator or other fiduciary of
         any  Plan or any  agent  of any of the  foregoing  has  engaged  in any
         transaction or acted in a manner that could, or has failed to act so as
         to, subject  American or any trustee,  administrator or other fiduciary
         to any liability for breach of fiduciary  duty under ERISA or any other
         Applicable Law;

                  (xii)  American has not  incurred any material  liability to a
         Plan (other than for contributions not yet due) which liability has not
         been fully paid or accrued for  payment as of the date of the  Original
         Merger Agreement;

                  (xiii) except as otherwise contemplated by this Agreement,  no
         current  or  former  employee  of  American  will  be  entitled  to any
         additional  benefits  or any  acceleration  of the time of  payment  or
         vesting  of any  benefits  under any Plan or Benefit  Arrangement  as a
         result of the transactions contemplated by this Agreement;

                  (xiv)  no  compensation  payable  by  American  to  any of its
         employees under any existing Plan,  Benefit  Arrangement  (including by
         reason of the  transactions  contemplated  hereby)  will be  subject to
         disallowance under Section 162(m) of the Code;

                  (xv) any amount  that could be  received  (whether  in cash or
         property  or  the  vesting  of  property)  as a  result  of  any of the
         transactions  contemplated by this Agreement by any employee,  officer,
         director or independent  contractor of American who is a  "disqualified
         individual"  (as such term is defined in proposed  Treasury  Regulation
         Section  1.280G-1)  under  any  employment  arrangement  would  not  be
         characterized as an "excess parachute payment" (as such term is defined
         in Section 280G(b)(1) of the Code);

                  (xvi) no Plan which is an employee  stock  ownership  plan (an
         "ESOP")  constitutes a leveraged  employee stock  ownership plan within
         the  meaning  of  Section  4975(e)(7)  of the  Code  and  there  are no
         unallocated  shares of stock of American  currently held under any such
         ESOP in a suspense account; and

                  (xvii)  there  are  no  outstanding  options  (or  contractual
         obligations to issue options) to acquire American Common Stock or other
         American  securities  other than options held by employees or directors
         of American and issued under Benefit Arrangements (the aggregate number
         of which are as set forth in Section  4.11 of the  American  Disclosure
         Schedule).

         (b)  The  execution,  delivery  and  performance  by  American  of this
Agreement and the  Collateral  Documents  executed or required to be executed by
American pursuant hereto and thereto will not involve any prohibited transaction
within the meaning of ERISA or Section 4975 of the Code.

         4.10  Insurance.  All material  fire and casualty,  general  liability,
business  interruption,  product  liability,  and  sprinkler  and  water  damage
insurance policies maintained by American or any of its Subsidiaries (other than
the Tower Subsidiaries) are with reputable insurance carriers,  provide full and
adequate  coverage,  for  American and such  Subsidiaries  (other than the Tower
Subsidiaries) and their respective  properties and assets,  and are in character
and amount at least  equivalent  to that  carried by Persons  engaged in similar
businesses  and subject to the same or similar  perils or hazards,  except where
the failure to maintain such insurance  policies,  either individually or in the
aggregate,  would not be reasonably  likely to have a Material Adverse Effect on
American.



                                      -17-


<PAGE>


         4.11 Authorized  Capital Stock. The authorized and outstanding  capital
stock, Option Securities and Convertible Securities of American, as of September
18, 1997, are as set forth in Section 4.11 of the American Disclosure  Schedule.
Except as set forth in Section 4.11 of the American Disclosure  Schedule,  since
September  18, 1997,  American has not issued any shares of capital stock of any
class, any Option Securities or any Convertible Securities, except for the issue
of American Common Stock pursuant to the conversion of Convertible Securities or
the exercise of Option Securities  outstanding on September 18, 1997 and in each
case in  accordance  with  their  present  terms or as  otherwise  described  or
contemplated  by the  Filed  American  SEC  Documents.  All of such  outstanding
capital stock has been duly  authorized  and validly  issued,  is fully paid and
nonassessable  and is not subject to any preemptive or similar rights.  American
had,  prior to the date of the  Original  Merger  Agreement,  made  available to
Mergeparty a true and correct copy of the Restated  Certificate of Incorporation
of  American  (the  "Restated  Certificate")  as in  effect  on the  date of the
Original Merger  Agreement.  Except as set forth in Section 4.11 of the American
Disclosure Schedule, there are no bonds, debentures, notes or other indebtedness
of  American  outstanding  having  the right to vote (or  convertible  into,  or
exchangeable  for,  securities having the right to vote) on any matters on which
stockholders  of American  may vote.  Except as set forth in Section 4.11 of the
American  Disclosure  Schedule,   or,  except  as  set  forth  in  the  Restated
Certificate,  there are no  contractual  obligations  of  American or any of its
Subsidiaries  outstanding to repurchase,  redeem or otherwise acquire any shares
of capital  stock of American or any of its  Subsidiaries.  Except as  otherwise
contemplated  by this  Agreement or as set forth in Section 4.11 of the American
Disclosure Schedule, there are no contractual obligations of American to vote or
to dispose of any shares of the  capital  stock of any of its  Subsidiaries.  No
adjustment  in  either  the  conversion  price or the  amount  or  nature of the
securities or other property  issuable upon conversion of the shares of American
Convertible  Preferred  Stock is required  as a result of (i) the Tower  Merger,
other than an  adjustment  to the effect  that,  upon  conversion,  the  holders
thereof shall have the right to receive the Tower Merger  Consideration upon any
conversion  following the Tower Merger Effective Time, as if such conversion had
been effected immediately prior to the Tower Merger Effective Time, and (ii) the
Merger,  other than an  adjustment  to the effect  that,  upon  conversion,  the
holders  thereof shall have the right to receive the Merger  Consideration  upon
any  conversion  following the  Effective  Time as if such  conversion  had been
effected  immediately prior to the Effective Time. No adjustment in the exercise
price or the number of shares of American  Common  Stock or the amount or nature
of any other  securities or property  issuable upon the exercise of the American
Options is required as result of (i) the Tower Merger,  other than an adjustment
to the effect that,  upon exercise,  the holders thereof shall have the right to
receive the Tower Merger  Consideration  upon any exercise  following  the Tower
Merger Effective Time, as if such exercise had been effected  immediately  prior
to the Tower Merger Effective Time and (ii) the Merger, other than an adjustment
to the effect that,  upon exercise,  the holders thereof shall have the right to
receive the Merger  Consideration upon any exercise following the Effective Time
as if such exercise had been effected immediately prior to the Effective Time.

         4.12 Employment Arrangements. Except as described in the Filed American
SEC Documents or in Section 4.12 of the American Disclosure Schedule,  as of the
date of the Original  Merger  Agreement (i) none of the employees of American or
any of its  Subsidiaries  (other  than  the  Tower  Subsidiaries)  was,  or,  to
American's  knowledge,  since November 1, 1993 and while an employee of American
or any of its  Subsidiaries  had been,  represented  by any labor union or other
employee  collective  bargaining  organization,  or were,  as of the date of the
Original Merger Agreement,  or, to American's knowledge,  since 

                                      -18-


<PAGE>

November 1, 1993 to such date had been, parties to any labor or other collective
bargaining agreement,  (ii) there are, to American's knowledge, no pending labor
strikes,  work stoppages,  lockouts,  slow downs,  grievances  (including unfair
labor charges),  disputes or controversies  with any union or any other employee
or collective  bargaining  organization  of such  employees,  or threats of such
labor strikes, work stoppages,  lockouts or slowdowns or any pending demands for
collective bargaining by any union or other such organization, and (iii) neither
American nor any of its Subsidiaries (other than the Tower Subsidiaries) nor any
of its or any of their  employees  was,  as of the date of the  Original  Merger
Agreement, or, to American's knowledge,  since November 1, 1993 to such date had
been,  subject to or involved in or, to American's  knowledge,  threatened with,
any union elections,  petitions  therefor or other  organizational or recruiting
activities.  American and its Subsidiaries  (other than the Tower  Subsidiaries)
have  performed all  obligations  required to be performed  under all Employment
Arrangements  and none of them is in breach or  violation  of or in  default  or
arrears under any of the terms,  provisions or  conditions  thereof,  except for
such breaches, violations, defaults and arrears, which either individually or in
the  aggregate,  have not had and are not  reasonably  likely to have a Material
Adverse Effect on American.

         4.13 Voting Requirements. The affirmative vote of the holders of shares
of American  Common Stock,  representing  a majority of the  outstanding  voting
power of American  Common Stock,  voting as a single class, is (i) the only vote
necessary to approve and adopt this Agreement and the transactions  contemplated
by this Agreement (other than the Tower Merger  Agreement) (the "Required Vote")
and (ii) the only vote necessary to approve and adopt the Tower Merger Agreement
and the  transactions  contemplated by the Tower Merger Agreement (the "Required
Tower Vote").

         4.14 Brokers. No broker,  investment banker, financial advisor or other
person, other than Credit Suisse First Boston Corporation ("CSFB"), the fees and
expenses of which will be paid by American,  and Merrill  Lynch Pierce  Fenner &
Smith  Incorporated,  the fees and  expenses  of which will be paid by  American
Tower (or reimbursed to American by American Tower) following the Effective Time
in  accordance  with the  provisions  of  Section  9.3(b),  is  entitled  to any
broker's,  finder's,  financial  advisor's or other similar fee or commission in
connection  with the  transactions  contemplated or permitted by this Agreement.
American has furnished to Mergeparty  true and complete copies of all agreements
under which any such fees or expenses may be payable and all indemnification and
other agreements  related to the engagement of the persons to whom such fees may
be payable.

         4.15 Information Supplied.

         (a) Each of the Proxy Statement and the Tower Proxy Statement will not,
at the date it is first  mailed to the holders of American  Common  Stock and at
the  time  of the  American  Stockholders  Meeting  (in the  case  of the  Proxy
Statement) and the American Stockholders Tower Meeting (in the case of the Tower
Proxy  Statement),  contain any untrue  statement of a material  fact or omit to
state any material fact  required to be stated  therein or necessary in order to
make the statements  therein, in light of the circumstances under which they are
made,  not  misleading.  For  purposes  of  the  foregoing,  the  truth  of  any
information  or the  existence  of any  omissions  at the  time of the  American
Stockholders  Meeting  and the  American  Stockholders  Tower  Meeting  shall be
determined with reference to the Proxy Statement and the Tower Proxy  Statement,
respectively, as then amended or supplemented. The Proxy Statement and the Tower
Proxy  Statement  will  comply  as to form in all  material  respects  with  the
requirements  of the  Exchange  Act and the  rules and  regulations  thereunder.
Notwithstanding the foregoing, no representation or warranty is made by American
with respect to statements made or  incorporated  by reference  therein based on
information  specifically  supplied by Mergeparty or Mergeparty  Subsidiary  for
inclusion or  incorporation  by  reference  in the Proxy  Statement or the Tower
Proxy Statement.

         (b) The  Registration  Statement  to be filed  with the  Commission  by
American  Tower pursuant to the provisions of Section 6.6(b) will not (except to
the extent  revised or  superseded by  amendments  or  supplements  contemplated
hereby),  at the time such Registration  Statement is filed with the Commission,
at the time such  Registration  Statement is amended or  supplemented  or at the
time such  Registration  Statement  becomes  effective under the Securities Act,
contain any untrue  statement  of a material  fact or omit to state any material
fact required to be stated  therein or necessary in order to make the statements
therein,  in  light  of the  circumstances  under  which  they  were  made,  not
misleading.

                                      -19-

<PAGE>


         4.16  Ordinary  Course of  Business.  Except as may be described in the
Filed  American  SEC  Documents  or in  Section  4.9(a) or  Section  4.16 of the
American  Disclosure  Schedule,  since June 30, 1997 to the date of the Original
Merger  Agreement,  (i) each of American  and its  Subsidiaries  (other than the
Tower Subsidiaries) has operated its business in the normal, usual and customary
manner in the ordinary and regular  course of  business,  consistent  with prior
practice  (it being  understood  and agreed for purposes of this Section 4.16 by
the parties that the acquisition,  disposition and exchange of radio stations is
in the ordinary  course of business) and (ii) there has not been by American and
its  Subsidiaries  (other  than the  Tower  Subsidiaries)  (a) any  declaration,
setting aside or payment of any dividend or other distribution  payable in cash,
stock,  property or  otherwise  except for (x) the payment of  dividends  or the
making of  distributions  by a direct or  indirect  wholly-owned  Subsidiary  of
American and (y) the payment of dividends on shares of American  Preferred Stock
in accordance with their terms, (b) any split,  combination or  reclassification
of any of its capital stock or any issuance or the authorization of any issuance
of any other  securities in respect of, in lieu of or in substitution for shares
of its capital stock, (c) (I) any granting to any executive officer or other key
employee of American or any of its Subsidiaries of any increase in compensation,
except for normal  increases in the ordinary course of business  consistent with
past practice or as required  under Benefit  Arrangements,  (II) any granting to
any such  executive  officer of any increase in severance  or  termination  pay,
except  as was  required  under any  Benefit  Arrangement,  (III)  except in the
ordinary  course,  any  entering  into,  amendment  in any  material  respect or
termination of any Governmental Authorization, Private Authorization or material
agreement,   arrangement,   contract,   undertaking,   understanding   or  other
obligation, or (IV) any adoption or amendment of any Plan or Benefit Arrangement
(including  changing any actuarial or other assumption used to calculate funding
obligations  with  respect  to  any  Plan,  or  changing  the  manner  in  which
contributions to any Plan are made or the basis on which such  contributions are
determined)  except as required to comply with  changes in  Applicable  Law, (d)
except insofar as may have been disclosed in the Filed American SEC Documents or
required by a change in GAAP,  any change in accounting  methods,  principles or
practices by American materially affecting its assets,  liabilities or business,
(e) any sale,  disposition  or contract to dispose of any of its  properties  or
assets having a value in excess of $1,000,000 other than in the ordinary course,
and (f) any damage,  destruction  or loss,  whether or not covered by insurance,
that has had a Material Adverse Effect on American.

         4.17  Environmental  Matters.  Except as set forth in the  American SEC
Documents or Section 4.17 of the American Disclosure Schedule, American:

                  (a)  (i)  has  not  been   notified  in  writing  that  it  is
         potentially  liable  and,  has not  received  any  written  request for
         information or other correspondence  concerning its potential liability
         with  respect  to any  site  or  facility,  under  or  pursuant  to any
         Environmental  Law,  (ii)  to  the  knowledge  of  American,  is  not a
         potentially "responsible party" under, the Comprehensive  Environmental
         Response,  Compensation  and  Liability  Act of 1980,  as amended,  the
         Resource  Conservation  and  Recovery  Act, as amended,  or any similar
         state Law, and (iii) to the  knowledge of American,  is not the subject
         of or, to the knowledge of American,  threatened  with any Legal Action
         involving a demand for damages or other potential liability,  including
         any Lien,  with respect to violations or breaches of any  Environmental
         Law;

                  (b) to the knowledge of American,  is in  compliance  with all
         Environmental Laws and has obtained all Environmental  Permits required
         under  Environmental  Laws, except for such noncompliances and failures
         to obtain  Environmental  Permits as, individually or in the aggregate,
         have not had and would  not be  reasonably  likely  to have a  Material
         Adverse Affect on American;

                  (c) (i) has not entered into or received  any consent  decree,
         compliance  order  or  administrative  order  issued  pursuant  to  any
         Environmental  Law,  and (ii) is not a party in  interest or 

                                      -20-


<PAGE>


         in default under any judgment, order, writ, injunction or decree of any
         Final Order issued pursuant to any Environmental Law; and

                  (d) to the  knowledge  of  American,  there  have not been any
         releases,  spills or  disposal  activities  of or  involving  Hazardous
         Materials, including without limitation from underground storage tanks,
         on or from any  property  owned,  operated or leased by American  which
         releases, spills or disposal activities resulted or could reasonably be
         expected to result in investigation and cleanup expenditures which upon
         payment  of such  expenditures  would be  reasonably  likely  to have a
         Material Adverse Effect on American.

         Notwithstanding  anything to the contrary  contained in this Agreement,
American makes no representation or warranty with respect to its compliance with
Environmental Laws or environmental  matters  generally,  except as specifically
set forth in this Section 4.17.

         4.18 Opinion of Financial Advisor. American has received the opinion of
CSFB, dated the date of the Original Merger Agreement, to the effect that, as of
such  date,  the  Merger  Consideration  (as  defined  in  the  Original  Merger
Agreement) to be received by the holders of American  Common Stock in the Merger
is fair from a financial point of view to the holders of American Common Stock.

         4.19 Contracts; Debt Instruments.

         (a)  Except as set forth in  Section  4.20 of the  American  Disclosure
Schedule,  neither American nor any of its Subsidiaries is in violation of or in
default under (nor does there exist any condition which upon the passage of time
or the giving of notice,  or both,  would cause such a  violation  of or default
under) any material agreement, arrangement, contract, undertaking, understanding
or other obligation,  including the American Preferred Stock  ("Contracts"),  to
which it is a party or by which it or any of its  properties or assets is bound,
except for violations or defaults, that individually or in the aggregate,  would
not be reasonably likely to have a Material Adverse Effect on American, and none
of the  Contracts  prohibits  American  from  incurring an  additional  $1.00 of
indebtedness.

         (b) American  has made  available  to  Mergeparty  (i) true and correct
copies of all  Contracts  to which any  indebtedness  of  American or any of its
Subsidiaries  (other  than the Tower  Subsidiaries)  in an  aggregate  principal
amount  in excess of  $1,000,000  is  outstanding  or may be  incurred  and (ii)
accurate  information  regarding  the  respective  principal  amounts  currently
outstanding as of the date of the Original Merger Agreement thereunder.

         4.20 State  Takeover  Statutes.  Except for  Section 203 of the DCL, to
American's knowledge, no other state takeover Law, statute or similar statute or
regulation applies or purports to apply to the Merger,  this Agreement or any of
the transactions contemplated by this Agreement.

         4.21 Appraisal Rights. No appraisal rights under Section 262 of the DCL
are applicable to the Tower Merger or the Tower Merger Consideration.


                                      -21-


<PAGE>

                                    ARTICLE 5

                  REPRESENTATIONS AND WARRANTIES OF MERGEPARTY

         Except  as  set  forth   with   respect  to   specifically   identified
representations and warranties in the Mergeparty Disclosure Schedule, Mergeparty
represents and warrants to American as follows:

         5.1  Organization  and  Business;   Power  and  Authority;   Effect  of
Transaction.

         (a) Each of Mergeparty and Mergeparty  Subsidiary is a corporation duly
incorporated,  validly  existing  and in good  standing  under  the  laws of its
jurisdiction  of  organization   and  has  all  requisite  power  and  authority
(corporate  and other) to own or hold under lease its  properties and to conduct
its business as now conducted and as presently proposed to be conducted. Each of
Mergeparty and Mergeparty Subsidiary is duly qualified and in good standing as a
foreign  corporation in each other  jurisdiction  (as shown on Section 5.1(a) of
the Mergeparty Disclosure Schedule) in which the character of the property owned
or leased by it or the  nature  of its  business  or  operations  requires  such
qualification,  with full power and authority  (corporate and other) to carry on
the  business in which it is  engaged,  except in such  jurisdictions  where the
failure  to be so  qualified  and  in  good  standing,  individually  or in  the
aggregate,  is not  reasonably  likely  to have a  Material  Adverse  Effect  on
Mergeparty.

         (b) Each of  Mergeparty  and  Mergeparty  Subsidiary  has all requisite
power and authority  (corporate  and other) to execute,  deliver and perform its
obligations  under this  Agreement  and each  Collateral  Document  executed  or
required to be executed by  Mergeparty  and/or  Mergeparty  Subsidiary  pursuant
hereto or  thereto  or to  consummate  the  Merger  and the  other  transactions
contemplated hereby and thereby, and the execution,  delivery and performance of
this Agreement and each Collateral  Document executed or required to be executed
pursuant  hereto have been duly  authorized by all requisite  corporate or other
action on the part of  Mergeparty  and/or  Mergeparty  Subsidiary,  and no other
corporate proceedings on the part of Mergeparty and/or Mergeparty Subsidiary are
necessary to authorize this Agreement or the transactions contemplated hereby or
to  consummate  the  Merger  or the other  transactions  so  contemplated.  This
Agreement  has been  duly  executed  and  delivered  by each of  Mergeparty  and
Mergeparty Subsidiary and constitutes,  and each Collateral Document executed or
required  to be  executed  pursuant  hereto or to  consummate  the  Merger  when
executed  and  delivered  by  Mergeparty  and/or   Mergeparty   Subsidiary  will
constitute,  a valid and binding  obligation  of  Mergeparty  and/or  Mergeparty
Subsidiary,  enforceable in accordance with their  respective  terms,  except as
such  enforceability  may be limited by bankruptcy,  moratorium,  insolvency and
similar laws  affecting the rights and remedies of creditors and  obligations of
debtors generally and by general principles of equity.

         (c) At the time of execution of this  Agreement,  Mergeparty and all of
its  Affiliates or  "associates"  (as defined in the Exchange Act)  collectively
beneficially  own less  than 5% of the  outstanding  shares of  American  Common
Stock.

         (d) The  execution,  delivery  and  performance  by each of  Mergeparty
and/or  Mergeparty  Subsidiary  of this  Agreement and any  Collateral  Document
executed or required to be executed by such party pursuant hereto or thereto, do
not, and the  consummation by Mergeparty  Subsidiary of the Merger and the other
transactions  hereby and thereby and compliance  with the terms,  conditions and
provisions  hereof or thereof by Mergeparty  and/or  Mergeparty  Subsidiary will
not:

                  (i) (A) conflict  with, or result in a breach or violation of,
         or constitute a default  under,  any Organic  Document of Mergeparty or
         Mergeparty   Subsidiary  or  (B)  any   Applicable  Law  applicable  to
         Mergeparty or Mergeparty  Subsidiary,  or conflict with, or result in a
         breach or violation  of, or constitute a default  under,  or permit the
         termination,   cancellation   or  acceleration  of  any 

                                      -22-


<PAGE>


         obligation or liability in, or but for any requirement of the giving of
         notice or  passage  of time or both  would  constitute  such a conflict
         with,  breach or  violation  of, or default  under,  or permit any such
         termination,  cancellation or acceleration  of, any Contract or Private
         Authorization of Mergeparty or Mergeparty  Subsidiary,  except,  in the
         case  of  clause  (B),  for  such  conflicts,   breaches,   violations,
         terminations,   cancellations   or   accelerations   that   would  not,
         individually  or in the  aggregate,  be  reasonably  likely  to  have a
         Material Adverse Effect on Mergeparty; or

                  (ii)  result in or permit the  creation or  imposition  of any
         Lien upon any property now owned or leased by  Mergeparty or Mergeparty
         Subsidiary except for such Liens that would not, individually or in the
         aggregate,  be reasonably  likely to have a Material  Adverse Effect on
         Mergeparty or Mergeparty Subsidiary; or

                  (iii) require any  Governmental  Authorization or Governmental
         Filing  except  for  (A)  the  FCC  Consents,  (B)  filings  under  the
         Hart-Scott-Rodino  Act,  (C) the  filing  with the  Commission  of such
         reports  under  Section  13(a) or 15(d) of the  Exchange  Act as may be
         required  in  connection  with  this  Agreement  and  the  transactions
         contemplated  by this  Agreement,  (D) the filing of the Certificate of
         Merger with the Delaware  Secretary of State and appropriate  documents
         with the  relevant  authorities  of other  states in which  American is
         qualified to do business and (E) such other Governmental Authorizations
         and  Governmental  Filings  the failure of which to be made or obtained
         would,  individually or in the aggregate,  not be reasonably  likely to
         have a Material Adverse Effect on American.

         (e) Mergeparty Subsidiary was formed solely for the purpose of engaging
in the  transactions  contemplated  by this Agreement and has not engaged in any
business  activities or conducted any operations  other than in connection  with
the transactions contemplated by this Agreement.

         5.2 Compliance  with  Governmental  Authorizations  and Applicable Law;
Litigation.  Except  as  disclosed  in any  report  or other  document  filed by
Mergeparty with the SEC prior to the date of the Original Merger Agreement or in
Section 5.2 of the Mergeparty  Disclosure  Schedule,  there are no Legal Actions
pending or, to the knowledge of Mergeparty, threatened against Mergeparty or any
of its  Subsidiaries,  except for Legal  Actions  that,  individually  or in the
aggregate,  would not be reasonably  likely to have a Material Adverse Effect on
Mergeparty or prevent or materially  burden or materially  impair the ability of
Mergeparty to consummate the transactions contemplated by this Agreement. Except
as set forth in Section 5.2 of the Mergeparty Disclosure Schedule, there are not
facts relating to Mergeparty (or any Affiliate thereof) under the FCA that would
disqualify  it (or any  Affiliate or  assignee)  from  obtaining  control of the
American  FCC Licenses or that would  prevent it (or any  Affiliate or assignee)
from  consummating  the  transactions  contemplated  by this  Agreement  or,  to
Mergeparty's knowledge,  materially delay the grant of the FCC Consents.  Except
as may be set forth in Section 5.2 of the Mergeparty  Disclosure Schedule, it is
not necessary for Mergeparty or any of its  Subsidiaries or other Affiliates (or
assigns)  to (a) seek or obtain  any  waiver  from the FCC,  (b)  dispose of any
interest in any media or communications  property or interest (including without
limitation any of the American Stations or the American Brokered Stations),  (c)
terminate  any  venture  or  arrangement,   or  (d)  effectuate  any  change  or
restructuring  of  ownership   (including  without  limitation  the  removal  or
withdrawal  of officers or directors or the  conversion  or repurchase of equity
securities in Mergeparty or any  Affiliate) to obtain,  or to avoid any delay in
obtaining,  the FCC  Consents.  Mergeparty is able to certify on an FCC Form 315
that it is financially qualified.

         5.3 Mergeparty  Financing.  On the Closing Date,  Mergeparty  will have
sufficient funds to consummate the transactions  contemplated by this Agreement,
including  without  limitation  the  Merger,  and to pay all  related  fees  and
expenses.


                                      -23-


<PAGE>


                                    ARTICLE 6

                                    COVENANTS

         6.1 Access to  Information;  Confidentiality.  American shall afford to
Mergeparty and its accountants,  counsel, investment bankers, financial advisors
and other agents and representatives (the  "Representatives") full access during
normal business hours  throughout the period prior to the Closing Date to all of
its  (and  its  Subsidiaries',  other  than  those  of the  Tower  Subsidiaries)
properties,  books,  contracts,   commitments  and  records  (including  without
limitation  Tax Returns) and,  during such period,  shall furnish  promptly upon
request (i) a copy of each report, schedule and other document filed or received
by it pursuant to the  requirements  of any Applicable  Law  (including  without
limitation  the FCA) or filed by it or any of its  Subsidiaries  (other than the
Tower  Subsidiaries)  with any Authority in connection  with the Merger or which
may have a material effect on it or its business, financial condition or results
of operations,  and (ii) such other information  concerning any of the foregoing
as Mergeparty shall reasonably request;  provided,  however,  that the foregoing
shall  not  require  American  to  permit  any  disclosure  or to  disclose  any
information,  that in the  reasonable  judgment of American  would result in the
disclosure  of  any  trade  secrets  of  third  parties  or  violate  any of its
obligations with respect to confidentiality if American shall have used its best
efforts  to obtain  the  consent  of such  third  party to such  inspections  or
disclosure.  All  requests  for  information  shall be directed to an  executive
officer of American or such other Persons as may be designated by American.  All
information disclosed pursuant to this Section or otherwise shall be governed by
the terms of the  Confidentiality  Agreement,  the terms and provisions of which
are  incorporated  herein by reference  with the same force and effect as though
set forth here in their entirety.  No investigation  pursuant to this Section or
otherwise  shall  affect any  representation  or  warranty  of  American in this
Agreement or any condition to the obligations of Mergeparty hereto.

         6.2 Agreement to Cooperate.

         (a) Upon the  terms and  subject  to the  conditions  set forth in this
Agreement,  each of the parties  hereto shall use best  efforts (x) to take,  or
cause to be  taken,  all  actions  and to do,  or cause to be done,  all  things
necessary,  proper or advisable to consummate the Merger and (y) to refrain from
taking, or cause to be taken, any action and to refrain from doing or causing to
be done, any thing which could impede or impair the  consummation of the Merger,
including,  in all  cases,  without  limitation  using its best  efforts  (i) to
prepare and file with the  applicable  Authorities  as  promptly as  practicable
after the execution of this Agreement all requisite  applications and amendments
thereto,  together with related  information,  data and  exhibits,  necessary to
request  issuance  of  orders  approving  the  Merger  by  all  such  applicable
Authorities,  (ii) to obtain all necessary or appropriate waivers,  consents and
approvals, (iii) to effect all necessary registrations, filings and submissions,
(iv)  to  defend  any  suit,   action  or   proceeding,   whether   judicial  or
administrative,  challenging the Merger or any of the transactions  contemplated
by the Merger Agreement, including seeking to lift any injunction or other legal
bar  to  the  Merger  (and,  in  such  case,  to  proceed  with  the  Merger  as
expeditiously as possible), and (v) to obtain the satisfaction of the conditions
specified  in  Article 7,  including  without  limitation  the  securing  of all
authorizations, consents, waivers, modifications, order or approvals referred to
in Sections  7.1(b) and 7.1(d)  and,  without  limiting  the  generality  of the
foregoing,  and notwithstanding any provision contained in this Agreement to the
contrary,  including  without  limitation  the last  sentence  of Section  6.10,
American  shall  not,  and shall not permit any Tower  Subsidiary  to,  take any
action or enter into any  agreement,  plan or  arrangement to take any action (a
"Prohibited Transaction") which could reasonably be expected to materially delay
the date of the American  Stockholders  Meeting or the Effective  Time (it being
understood  that any delay in excess of fifteen (15)  business  days which would
arise as a result of any such action  shall be deemed  "material"  for  purposes
hereof).  American  hereby  agrees to  provide  Mergeparty  with  prior  written
notification  of any  proposed  action  which  could  reasonably  be expected to
constitute a Prohibited Transaction.


                                      -24-


<PAGE>


         (b) Without  limiting  the  generality  of the  foregoing,  the parties
acknowledge  and agree that the transfer of control of the American FCC Licenses
as  contemplated  by this Agreement is subject to the prior consent and approval
of the FCC. American and Mergeparty  acknowledge that they have heretofore filed
with the FCC  appropriate  applications  requesting the FCC's written consent to
the transfer of control of the American FCC Licenses  pursuant to this Agreement
and have caused all necessary  persons to join in one or more such  applications
filed with the FCC (the "Applications").  American and Mergeparty will use their
best efforts to take such steps as may be necessary (i)  diligently to prosecute
the Applications and to prepare and file any further  Applications or amendments
as may be  necessary  to obtain  the  consent  for the  transfer  of  control to
Mergeparty of the licenses held by the American Brokered Stations to be acquired
by American and (ii) to obtain the FCC Consents, including action by Mergeparty,
at its sole cost and expense (except as provided  elsewhere in this  Agreement),
to  satisfy or cause to be  removed  all  Divestiture  Conditions,  if any.  The
failure by  American  or  Mergeparty  to use its best  efforts to timely file or
diligently  prosecute  its  portion  of  any  Application  or,  in the  case  of
Mergeparty, the failure to use its best efforts to make any Required Divestiture
or otherwise  satisfy or cause to be removed all  Divestiture  Conditions  on or
before  the  Termination  Date,  shall  be a  material  breach  by  American  or
Mergeparty,  as the case may be, of this  Agreement.  American  agrees  that any
delay in prosecuting the  Applications  or obtaining the FCC Consents  resulting
from Mergeparty's good faith  negotiations,  subject to Applicable Law, with the
FCC,  Antitrust  Division or FTC with respect to the imposition of a Divestiture
Condition  shall not  constitute a failure by Mergeparty to use its best efforts
diligently to prosecute the  Applications or obtain the FCC Consents and so long
as such  negotiations  do not interfere with  satisfaction  of all conditions to
Closing prior to the Termination Date. If  reconsideration or judicial review is
sought with respect to any FCC Consent,  American and Mergeparty shall (promptly
and with all due  efforts)  oppose  such  efforts to obtain  reconsideration  or
judicial review.

         (c) Without  limiting the  generality  of Section  6.2(a),  the parties
undertake and agree to file as soon as practicable after the date hereof, and in
any event within  sufficient  time to be able to consummate  the Merger prior to
the Termination Date, a Notification and Report Form under the Hart-Scott-Rodino
Act with the Federal Trade Commission (the "FTC") and the Antitrust  Division of
the Department of Justice (the "Antitrust Division").  Each of the parties shall
(i) use its best efforts to comply as  expeditiously as possible with all lawful
requests of the FTC or the Antitrust  Division for  additional  information  and
documents and (ii) not extend any waiting period under the Hart-Scott-Rodino Act
or  enter  into any  agreement  with the FTC or the  Antitrust  Division  not to
consummate the  transactions  contemplated  by this  Agreement,  except with the
prior written consent of the other party hereto; provided, however, that nothing
shall limit the ability of Mergeparty to extend the 20-day  waiting period under
the Hart-Scott-Rodino Act following substantial  compliance with any request for
additional information that may be forthcoming,  if such extension is reasonably
necessary  to allow the  continuation  of  good-faith  negotiations  intended to
remove any objection to the transaction  that the FTC or Antitrust  Division may
have asserted,  and if such extension will expire not less than 30 days prior to
the Termination Date.

         (d) Anything in this Agreement,  including without  limitation  Section
6.2(b),  to the  contrary  notwithstanding,  Mergeparty  shall  obtain  the  FCC
Consents and  clearances  under the  Hart-Scott-Rodino  Act and the grant of any
waivers in connection therewith prior to the Termination Date in accordance with
this  Agreement  unless the failure to obtain such FCC Consents,  clearances and
waivers  is  primarily  the  result of one or more  Uncontrollable  Events.  For
purposes of this Agreement, the term "Uncontrollable Events" shall mean (i) acts
or omissions on the part of American or any of its  Subsidiaries  in  conducting
its  respective  operations  other than those relating to the number of American
FCC Licenses or amount of revenues in a particular market, (ii) an unremedied or
unwaived material breach by American of its obligations under this Agreement, or
(iii) any change in or enactment of Applicable Law by Congress and signed by the
President  and  which  (A) has the  effect  of  decreasing  the  number of radio
licenses  which a Person may own  nationally  or locally or (B)  materially  and
adversely  relates to the concentration of radio licenses which a Person may 

                                      -25-


<PAGE>

own in a market,  and as a result  of the  change or  enactment  referred  to in
either  clause (A) or (B) above,  Mergeparty's  performance  of its  obligations
under this Agreement would have a Material Adverse Effect on Mergeparty's  radio
and television broadcasting business. Mergeparty shall file with the FCC, within
sufficient  time to permit timely grant of the  Applications,  applications  for
consent to assign or transfer,  pursuant to trust  arrangements  satisfying  the
FCC's local multiple ownership rules and policies, such radio broadcast stations
as Mergeparty may designate,  so that the radio broadcast stations of Mergeparty
and  American  not  designated  for such trust  arrangements  may be held by the
Surviving  Corporation  in compliance  with the FCC's local  multiple  ownership
rules and policies. Mergeparty shall, to the extent necessary to obtain grant of
the  trust  applications,  thereafter  promptly  file or cause  to be filed  any
further applications  (including applications to assign radio broadcast stations
to  third  party  purchasers  for  value)  that  may be  required  by  the  FCC.
Notwithstanding the two preceding sentences,  with regard to stations located in
the San Jose  market,  the  obligations  of  Mergeparty  to submit trust or sale
applications  shall be  excused  for such  stations  to the  extent  and for the
duration of the period that  Mergeparty is unable to identify the stations to be
placed in trust or sold because of the failure of American to notify  Mergeparty
of the resolution of the Antitrust  Division  impediment  impacting the American
transactions pending in the San Jose market.

         (e) If Mergeparty or any of its Affiliates  receives an  administrative
or other order or notification relating to any violation or claimed violation of
the rules and  regulations  of the FCC,  or of any  other  Authority  (including
without limitation seeking or relating to a Divestiture  Condition),  that could
affect  Mergeparty's  or  Mergeparty  Subsidiary's  ability  to  consummate  the
transactions  contemplated  hereby,  or if Mergeparty or any other  Affiliate of
Mergeparty  should  become aware of any fact relating to the  qualifications  of
Mergeparty or any of its Affiliates that  reasonably  could be expected to cause
the FCC to withhold its consent to the  assignment of the American FCC Licenses,
Mergeparty shall promptly notify American thereof and American shall do likewise
with Mergeparty and Mergeparty  shall use its best efforts,  and take such steps
as are necessary,  in order to satisfy or remove the  Divestiture  Conditions to
enable the Closing to occur prior to the Termination Date.  Mergeparty covenants
and agrees to keep  American  fully  informed as to all matters  concerning  all
Required  Divestitures  and shall promptly notify American in writing of any and
all significant developments relating thereto and American agrees to do likewise
with Mergeparty.

         (f)  Mergeparty  acknowledges  and agrees that  certain of the American
Stations and American  Brokered  Stations may file  applications  for renewal of
license  during the time that an  application  for the FCC  Consents  is pending
before the FCC.  To the extent any such  application  for  renewal may be filed,
Mergeparty  agrees to amend the transferee's  portion of any application for the
FCC Consents and, as may be required,  to amend any license renewal applications
for all of the  American  Stations or  American  Brokered  Stations,  to confirm
Mergeparty's  intention to consummate this Agreement during the pendency of such
license renewal application,  and to agree to assume the consequences associated
with succeeding to the place of American in such license  renewal  applications.
The  making  of this  statement  shall not be deemed to limit or waive any other
rights that Mergeparty may otherwise have under this Agreement.

         (g) The parties shall  cooperate  with one another in the  preparation,
execution and filing of all Tax Returns, questionnaires,  applications, or other
documents  regarding any real property transfer or gains,  sales, use, transfer,
value  added,   stock  transfer  and  stamp  Taxes,  any  transfer,   recording,
registration  and other fees,  and any similar  Taxes  which  become  payable in
connection  with the Merger  that are  required or  permitted  to be filed on or
before the Closing Date.

         (h) Subject to Applicable Laws relating to the exchange of information,
American,  on the one hand, and  Mergeparty,  on the other hand,  shall have the
right to review in advance,  and to the extent practicable each will consult the
other with respect to, all the  information  relating to American or Mergeparty,
as the case may be, and any of their respective Subsidiaries, that appear in any
filing made with, or written materials  submitted to, any Authority and/or other
Person in connection with the Merger and the other 

                                      -26-


<PAGE>

transactions  contemplated by this Agreement. In exercising the foregoing right,
each of  American  and  Mergeparty  shall  act  reasonably  and as  promptly  as
practicable.

         6.3  Public  Announcements.  Until  the  Closing,  or in the  event  of
termination  of this  Agreement,  each party shall consult with the other before
issuing any press release or otherwise making any public statements with respect
to this  Agreement  or the Merger and shall not issue any such press  release or
make  any  such  public  statement  without  the  prior  consent  of the  other.
Notwithstanding the foregoing,  the parties acknowledge and agree that they may,
without  each  other's  prior  consent,  issue such press  releases or make such
public  statements as may be required by  Applicable  Law, in which case, to the
extent  practicable,  they will  consult  with the other  regarding  the nature,
content and form of such press release or public statement.

         6.4  Notification  of Certain  Matters.  Each party  shall give  prompt
notice  to the  other,  of the  occurrence  or  non-occurrence  of any Event the
occurrence or  non-occurrence  of which would be reasonably  likely to cause (i)
any  representation  or warranty  made by it contained  in this  Agreement to be
untrue or inaccurate  in any material  respect or (ii) any failure made by it to
comply with or satisfy,  or be able to comply with or satisfy,  in any  material
respect,  any covenant,  condition or agreement to be complied with or satisfied
by it under this Agreement in any material respect, such that, in any such case,
one or more of the  conditions  of  Closing  would not be  satisfied;  provided,
however,  that the  delivery of any notice  pursuant to this  Section  shall not
limit or  otherwise  affect the rights and remedies  available  hereunder to the
party  receiving  such notice or the  obligations of the party  delivering  such
notice and shall  not,  in any event,  affect the  representations,  warranties,
covenants and  agreements of the parties or the  conditions to their  respective
obligations under this Agreement.

         6.5  Stockholder  Approval.  American  will,  as  soon  as  practicable
following the date thereof,  establish  separate  record dates (which will be as
soon as practicable  following the date hereof) for, duly call,  give notice of,
convene and hold (on separate  dates) (i) a meeting (the "American  Stockholders
Meeting")  of the holders of shares of American  Common Stock for the purpose of
obtaining the Required Vote and (ii) a meeting (the "American Stockholders Tower
Meeting")  of  holders of shares of  American  Common  Stock for the  purpose of
obtaining  the  Required  Tower  Vote.  American  will,  through  its  Board  of
Directors,  recommend to the holders of shares of American Common Stock approval
and adoption of this  Agreement and the Tower Merger  Agreement,  subject,  with
respect to approval and adoption of this Agreement,  to the fiduciary  duties of
the Board of Directors of American under Applicable Law.

         6.6 Proxy Statement; Registration Statement.

         (a) American  shall prepare and file with the  Commission as soon as is
reasonably  practicable  after the date hereof a proxy  statement in  connection
with the  American  Stockholders  Meeting  (the "Proxy  Statement")  and a proxy
statement in connection with the American Stockholders Tower Meeting (the "Tower
Proxy Statement"),  in each case complying with applicable rules and regulations
of the Commission and the DCL.

         (b) American  shall cause  American  Tower to prepare and file with the
Commission  as soon  as is  reasonably  practicable  after  the  date  hereof  a
registration statement on Form S-4 (the "Registration Statement") complying with
applicable rules and regulations of the Commission.  The Registration  Statement
shall cover the  registration  under the  Securities  Act of the shares of Tower
Common Stock to be delivered  as the Tower Stock  Consideration  or Tower Merger
Tower  Consideration  to the holders of shares of American  Common  Stock at the
Effective Time or the Tower Merger Effective Time, as the case may be.

         (c)  Mergeparty and American  shall,  and American shall cause American
Tower to,  promptly  furnish to the other all  information,  and take such other
actions,  as may reasonably be requested in connection

                                      -27-


<PAGE>

with any action taken to comply with the provisions of this Section 6.6. Each of
American and  Mergeparty  shall,  and American  shall cause  American  Tower to,
correct promptly any information  provided by it to be used  specifically in the
Proxy Statement,  the Tower Proxy Statement or the  Registration  Statement that
shall have become false or misleading in any material respect and shall take all
steps  necessary to file with the  Commission and have cleared by the Commission
any amendment or supplement to the Proxy Statement, the Tower Proxy Statement or
the  Registration  Statement so as to correct such Proxy  Statement,  such Tower
Proxy Statement or such  Registration  Statement and cause it to be disseminated
to the  stockholders  of American,  to the extent  required by  Applicable  Law.
Without  limiting the generality of the foregoing,  American shall, and American
shall cause American Tower to, notify Mergeparty  promptly of the receipt of the
comments of the  Commission  and of any request by the Commission for amendments
or  supplements  to the  Proxy  Statement,  the  Tower  Proxy  Statement  or the
Registration  Statement,  or  for  additional  information,   and  shall  supply
Mergeparty with copies of all correspondence  between it or its representatives,
on the one hand, and the Commission or members of its staff,  on the other hand,
with  respect  to  the  Proxy  Statement,  the  Tower  Proxy  Statement  or  the
Registration  Statement.  Whenever any event occurs which should be described in
an amendment or a supplement to the Proxy  Statement,  the Tower Proxy Statement
or the Registration Statement, American shall, and American shall cause American
Tower to, upon learning of such event, promptly prepare, file and clear with the
Commission and, if prior to the Effective Time, mail to the holders of shares of
American  Common Stock such amendment or supplement;  provided,  however,  that,
prior to such mailing,  (i) American  shall,  and American  shall cause American
Tower to, consult with  Mergeparty with respect to such amendment or supplement,
(ii) shall afford  Mergeparty  reasonable  opportunity to comment  thereon,  and
(iii) each such  amendment or  supplement  shall be reasonably  satisfactory  to
Mergeparty.

         6.7  Miscellaneous.  Nothing contained in this Agreement shall prohibit
American  from  (a)  taking  and  disclosing  to  its  stockholders  a  position
contemplated by Rules 14d-9 and 14e-2(a)  promulgated  under the Exchange Act or
(b) making  any  disclosure  to  American's  stockholders  if, in the good faith
judgment of the  majority of the members of the Board of  Directors of American,
after  consultation  with independent  counsel,  failure to so disclose would be
inconsistent with Applicable Laws.

         6.8 Option Plans.

         (a) All unexpired  options to purchase  American  Common Stock that are
outstanding  immediately  prior  to  the  Effective  Time  (each,  an  "American
Option"),  except as provided otherwise in this Section 6.8, will be canceled by
American  immediately  prior to the Effective Time. Each employee or director of
American or any of its  Subsidiaries  immediately  prior to the  Effective  Time
(each, an "Optionholder")  shall receive, with respect to each share of American
Common Stock  subject to an unexpired  American  Option of the  Optionholder  so
canceled  by  American,  the  Merger  Consideration,  or,  if the  Tower  Merger
Effective Time shall have occurred,  the cash that the  Optionholder  would have
received  pursuant to the Merger and shares of American  Tower Common Stock that
the Optionholder  would have received pursuant to the Tower Merger, in each case
with  respect to each share of American  Common  Stock  subject to an  unexpired
American  Option of the  Optionholder  had such American  Option been  exercised
immediately prior to the Tower Merger Effective Time, in all cases reduced by an
amount of cash (and, to the extent  necessary,  Tower Common Stock) equal to the
exercise  price per share of  American  Common  Stock  subject to such  American
Option.  Except as provided in the preceding  sentence,  no other  consideration
will be paid by American to an  Optionholder  in respect of his or her  canceled
American  Options.  If the Merger is not  consummated,  the  cancellation of the
Optionholder's  American Options shall be rescinded and the  Optionholder  shall
continue to hold such American Options upon their original terms and conditions.
At the election of any Optionholder who is a "disqualified  individual" (as such
term is defined in proposed Treasury Regulation Section 1.280G-1),  this Section
6.8(a) will be  inoperative  with respect to such American  Options as he or she
may  specify to the  extent  that the  acceleration,  vesting  cancellation  and
cash-out of American  Options at the  Effective  Time as provided  herein  would
constitute  an "excess  parachute  payment"  (as such term is defined in Section
280G(b)(1) of the 
                                      -28-


<PAGE>


Code).  Any  Optionholder  who makes such  election  shall  forfeit the American
Options which are subject to such  election and shall  receive no  consideration
therefor.

         (b)  With  respect  to  American   Options  held  by  Tower  Employees,
notwithstanding  the  foregoing  provisions  of  this  Section  6.8  and in lieu
thereof,  and subject to the approval of the  provisions  of this Section 6.8 by
the Board of Directors of American and the Compensation  Committee thereof, such
Tower  Employees may elect to have their  American  Options  assumed by American
Tower and converted into options to acquire Tower Common Stock as of the earlier
to  occur of the  Tower  Merger  Effective  Time and the  Effective  Time,  such
conversion to be  effectuated  in a manner that will preserve the spread in such
American  Options between the option exercise price and the fair market value of
American  Common  Stock at the  time of such  conversion,  and the  ratio of the
spread  to the  exercise  price  prior to such  conversion  and,  to the  extent
applicable,  otherwise in conformity  with the rules under Section 424(a) of the
Code and the  regulations  promulgated  thereunder.  To the  extent  that  Tower
Employees  elect to so convert  their  American  Options into options to acquire
Tower Common Stock, American shall contribute (without the payment of any amount
or the issuance of any securities by American  Tower) to the capital of American
Tower at the time of such  conversion  a number of shares of Tower  Common Stock
equal to the excess,  if any, of (i) the number of shares of Tower  Common Stock
owned by American  immediately  prior to the Tower Merger  Effective Time or the
Effective  Time,  as the case may be,  over  (ii) the  number of shares of Tower
Common Stock  required to be delivered  (x) to the holders of shares of American
Common Stock,  (y) to holders of American  Options pursuant to the provisions of
Section 6.8(a), and (z) upon conversion of American Convertible Preferred Stock.
If the Tower Employees set forth on Schedule 4.1(e) do not enter into definitive
agreements  prior to the earlier to occur of the Tower Merger Effective Time and
the Effective Time to convert the American  Options which are held by such Tower
Employees  and set forth on such  Schedule  into options to acquire Tower Common
Stock in  accordance  with this Section  6.8(b),  American  shall,  prior to the
earlier to occur of the Tower  Merger  Effective  Time and the  Effective  Time,
cause  American  Tower to issue to American  in exchange  for payment of the par
value  thereof a number of shares of Tower Common  Stock equal to the  aggregate
number of shares of American  Common Stock subject to such American  Options set
forth on such  Schedule.  American  shall cause American Tower to file with, and
cause to be declared effective prior to the earlier to occur of the Tower Merger
Effective  Time  or  the  Effective  Time  under  the  Securities  Act  by,  the
Commission, a registration statement on Form S-8 to register the shares of Tower
Common Stock subject to such  converted  American  Options under the  Securities
Act.

         (c)  American  will use its best  efforts  (including  best  efforts to
obtain any consents of Optionholders,  if required) to cause the cancellation of
all of the American Options immediately prior to the Effective Time.

         (d)  Notwithstanding  the foregoing  provisions of this Section 6.8, in
the event that any amount  payable under Section  6.8(a) to an  Optionholder  in
respect of his American  Options would fail to be deductible by American (or any
successor  thereto) solely by reason of ss.162(m) of the Code (after taking into
account  all  amounts  paid  or  reasonably   expected  to  be  payable  to  the
Optionholder in the same taxable year in which the payments under Section 6.8(a)
are made to the  Optionholder  and  which  are not  otherwise  exempt  from Code
ss.162(m) in  determining  whether any amount payable to the  Optionholder  will
fail to be  deductible  thereunder),  then,  with respect to such portion of the
Optionholder's  American Options the cancellation and cash-out of which would be
nondeductible  under said ss.162(m) (the  "ss.162(m)  Options"),  such ss.162(m)
Options  shall be canceled in accordance  with the foregoing  provisions of this
Section 6.8, but the payments  contemplated  in Section 6.8(a) in respect of the
Optionholder's  ss.162(m) Options shall be made to the Optionholder on the 110th
day following the Effective Time.  American shall use its best efforts to obtain
the written consent of each Optionholder  affected by this Section 6.8(e) to the
foregoing provisions hereof.


                                      -29-


<PAGE>

         (e) All amounts payable  hereunder to an Optionholder  shall be reduced
by any applicable withholding taxes.

         Notwithstanding  anything to the contrary in this  Agreement,  American
shall have the right,  in its sole and absolute  discretion,  to accelerate,  on
such  terms  and  conditions  as it shall  determine,  in whole or in part,  the
vesting of any or all of the  American  Options  outstanding  on the date hereof
(other than the ss.162(m) Options) so that such American Options are exercisable
in full prior to the Effective Time.

         6.9  Conduct of Business by  Mergeparty  Pending the Merger.  Except as
otherwise  contemplated  by this  Agreement,  or as has been publicly  disclosed
prior  to the  date of the  Original  Merger  Agreement,  after  the date of the
Original Merger  Agreement and prior to the Closing Date or earlier  termination
of this Agreement unless American shall otherwise agree in writing, with respect
to  Mergeparty's   media  business,   Mergeparty  shall,  and  shall  cause  its
Subsidiaries, to:

                  (i) conduct  their  respective  businesses in the ordinary and
         usual  course of business  and  consistent  with past  practice,  which
         includes the acquisition of other radio broadcasting stations;

                  (ii) not amend or propose to amend its  Organic  Documents  in
         any manner materially  adverse to the holders of the American Preferred
         Stock;

                  (iii) use all best efforts to preserve intact their respective
         business  organizations  and goodwill,  keep  available the services of
         their respective  present officers and key employees,  and preserve the
         goodwill and business  relationships  with  customers and others having
         business relationships with them and not engage in any action, directly
         or  indirectly,  with the intent to adversely  affect the  transactions
         contemplated by this Agreement; and

                  (iv) not  authorize  or enter  into any  agreement  that would
         violate any of the foregoing.

         6.10 Conduct of Business by American Pending the Merger.  Except as set
forth in  Section  6.10 of the  American  Disclosure  Schedule  or as  otherwise
contemplated by this Agreement,  including  without  limitation the transactions
contemplated by the Tower Documentation and Section 6.19 hereof,  after the date
of the  Original  Merger  Agreement  and prior to the  Closing  Date or  earlier
termination of this Agreement,  unless  Mergeparty  shall  otherwise  consent in
writing, American shall, and shall cause its Subsidiaries, to:

                  (i) conduct  their  respective  businesses in the ordinary and
         usual course of business and consistent with past practice;

                  (ii)  not (A)  amend or  propose  to  amend  their  respective
         Organic Documents,  (B) split,  combine or reclassify (whether by stock
         dividend or  otherwise)  their  outstanding  capital  stock or issue or
         authorize  the issuance of any other  securities in respect of, in lieu
         of, or in substitution for shares of its capital stock, or (C) declare,
         set aside or pay any dividend or distribution  payable in cash,  stock,
         property or  otherwise,  except for (x) the payment of dividends or the
         making of distributions by a direct or indirect wholly-owned Subsidiary
         of American  and (y) the payment of dividends on shares of the American
         Preferred Stock in accordance with their terms;

                  (iii)  not  issue,  sell,  pledge or  dispose  of, or agree to
         issue,  sell,  pledge or dispose of, any shares of its  capital  stock,
         Convertible  Securities or Option Securities,  except that American may
         issue shares of American  Common Stock upon  conversion of  Convertible
         Securities  and exercise of Option  Securities  outstanding on the date
         hereof and in accordance with their present terms;

                                      -30-
<PAGE>


                  (iv) not (A) incur or become  contingently liable with respect
         to any indebtedness other than (x) short-term  borrowings not to exceed
         $25  million  in  the  aggregate  outstanding  at  any  one  time,  (y)
         borrowings to finance pending  acquisitions of radio stations set forth
         in Section 6.10 of the American  Disclosure  Schedule and,  pursuant to
         agreements in effect on the date of the Original  Merger  Agreement and
         (z)  borrowings  not to  exceed  $120  million  to  finance  a  capital
         contribution  by American to Tower,  (B) redeem,  purchase,  acquire or
         offer  to  purchase  or  acquire  any  shares  of  its  capital  stock,
         Convertible  Securities or Option  Securities,  except  pursuant to the
         conversion  or exercise  thereof,  as the case may be, or except to the
         extent required by the present terms thereof, (C) sell, lease, license,
         pledge,  dispose of or encumber  any  properties  or assets or sell any
         businesses  other than  pursuant to agreements in effect on the date of
         the  Original  Merger  Agreement  and set forth in Section  6.10 of the
         American  Disclosure  Schedule or Liens arising in accordance  with the
         provisions of indebtedness in effect on the date of the Original Merger
         Agreement and in accordance  with their present terms,  or (D) make any
         loans,  advances or capital  contributions  to, or investments  in, any
         other  Person,  other  than to any  direct  or  indirect  wholly  owned
         Subsidiary of American (other than the Tower  Subsidiaries) and, except
         as  provided  in clause (z) above,  or to  officers  and  employees  of
         American or any of its Subsidiaries for travel,  business or relocation
         expenses in the ordinary course of business;

                  (v)  use all  reasonable  efforts  to  preserve  intact  their
         respective  business  organizations  and goodwill,  keep  available the
         services of their respective  present  officers and key employees,  and
         preserve the goodwill and business  relationships  with  customers  and
         others having  business  relationships  with them and not engage in any
         action, directly or indirectly, with the intent to adversely impact the
         transactions contemplated by this Agreement;

                  (vi) confer on a regular and  frequent  basis with one or more
         representatives  of Mergeparty to report material  operational  matters
         and the general status of ongoing operations;

                  (vii)  not  adopt,   enter  into,   amend  or  terminate   any
         employment,   severance,   special  pay  arrangement  with  respect  to
         termination of employment or other similar  arrangements  or agreements
         with any directors, officers or key employees;

                  (viii)  maintain  with   financially   responsible   insurance
         companies  insurance  on their  respective  tangible  assets  and their
         respective businesses in such amounts and against such risks and losses
         as are consistent with past practice;

                  (ix) not make any Tax election that could reasonably be likely
         to have a Material  Adverse  Effect on American or settle or compromise
         any material income Tax liability;

                  (x) except in the  ordinary  course of  business  or except as
         would not  reasonably  be likely to have a Material  Adverse  Effect on
         American,  not modify,  amend or terminate  any  Material  Agreement to
         which American or any Subsidiary is a party or waive, release or assign
         any material rights or claims thereunder;

                  (xi) not make any material  change to its accounting  methods,
         principles or practices, except as may be required by GAAP;

                  (xii)  not  acquire  or agree to  acquire  (x) by  merging  or
         consolidating  with,  or by  purchasing  a  substantial  portion of the
         assets of, or by any other manner,  any business or any Person or other
         business  organization  or  division  thereof or (y) any  assets  that,
         individually  or in the  aggregate,  are  material to American  and its
         Subsidiaries  taken as a whole,  in each case,  other than  pursuant to
        
                                      -31-


<PAGE>


 agreements in effect on the date of the Original  Merger  Agreement and
         set  forth in the  Section  6.10 of the  American  Disclosure  Schedule
         (Mergeparty agrees not to unreasonably  withhold,  delay or condition a
         consent to any matters described in this paragraph);

                  (xiii)  except as set forth in Section  4.9(a) or Section 4.16
         of the American  Disclosure  Schedule,  (a) not grant to any  executive
         officer or other key  employee of  American or any of its  Subsidiaries
         any  increase  in  compensation,  except  for normal  increases  in the
         ordinary  course  of  business  consistent  with  past  practice  or as
         required under Benefit  Arrangements in effect as of June 30, 1997, (b)
         not grant to any such  executive  officer any  increase in severance or
         termination pay, except as was required under any Benefit  Arrangements
         in  effect  as of June 30,  1997,  (c) not  adopt or amend  any Plan or
         Benefit Arrangement (including change any actuarial or other assumption
         used to calculate  funding  obligations  with  respect to any Plan,  or
         change  the manner in which  contributions  to any Plan are made or the
         basis on which such contributions are determined) and (d) except in the
         ordinary  course,  not enter  into,  amend in any  material  respect or
         terminate  any  Governmental  Authorization  (except  as  would  not be
         reasonably  likely to have a  Material  Adverse  Effect  on  American),
         material Private Authorization or Contract; and

                  (xiv) not  authorize  or enter into any  agreement  that would
         violate any of the foregoing.  

Anything in this Section to the contrary notwithstanding, the provisions of this
Section  (other  than clause  (ii)  hereof)  shall not apply to any of the Tower
Subsidiaries.

         6.11 Control of Operations.  Nothing  contained in this Agreement shall
give to  Mergeparty,  directly  or  indirectly,  rights  to  control  or  direct
American's  operations prior to the Effective Time. Prior to the Effective Time,
American  shall  exercise,  consistent  with the  terms and  conditions  of this
Agreement, complete control and supervision of its operations. Nothing contained
in this  Agreement  shall give to American,  directly or  indirectly,  rights to
control or direct Mergeparty's  operations prior to the Effective Time. Prior to
the Effective Time,  Mergeparty  shall  exercise,  consistent with the terms and
conditions  of  this  Agreement,   complete   control  and  supervision  of  its
operations.

         6.12   Directors',   Officers'  and  Employees'   Indemnification   and
Insurance.

         (a) The Organic  Documents of the Surviving  Corporation  shall contain
provisions no less favorable with respect to indemnification  than are set forth
in the Organic  Documents of American,  as in effect on the date of the Original
Merger Agreement,  which provisions shall not be amended,  repealed or otherwise
modified  for a period of six (6) years  from the  Effective  Time in any manner
that would affect adversely the rights thereunder of individuals who at any time
prior to the Effective Time were directors, officers or employees of American or
any  of  its  Subsidiaries,  unless  such  modification  shall  be  required  by
Applicable Law.

         (b) From and after the  Effective  Time,  Mergeparty  shall  indemnify,
defend  and hold  harmless  the  present  and  former  officers,  directors  and
employees of American or any of its Subsidiaries (collectively, the "Indemnified
Parties") against all losses, expenses, claims, damages,  liabilities or amounts
that are paid in  settlement  of, or  otherwise  in  connection  with any claim,
action,  suit,  proceeding or investigation (as used in this Section, a "claim")
(including,  without limitation,  in connection with this Agreement,  the Merger
and the transactions contemplated hereby), based in whole or in part on the fact
that the Indemnified Party (or the Person  controlled by the Indemnified  Party)
is or was a director, officer or employee of American or any of its Subsidiaries
and arising out of actions or omissions  occurring at or prior to the  Effective
Time whether  asserted or claimed prior to, at or after the  Effective  Time, in
each case to the  fullest  extent  permitted  under

                                      -32-


<PAGE>

  the DCL (and  shall pay any
expenses, as incurred, in advance of the final disposition of any such action or
proceeding to each  Indemnified  Party to the fullest extent permitted under the
DCL).  Without  limiting the  foregoing,  in the event any such claim is brought
against any of the Indemnified  Parties, (i) such Indemnified Parties may retain
counsel  (including  local  counsel)  satisfactory  to them and  which  shall be
reasonably satisfactory to Mergeparty and they shall pay all reasonable fees and
expenses of such counsel for such Indemnified Parties; and (ii) Mergeparty shall
use its best  efforts  to assist in the  defense  of any such  claim;  provided,
however, that Mergeparty shall not be liable for any settlement effected without
its written consent, which consent shall not be unreasonably  withheld,  delayed
or conditioned. Notwithstanding the foregoing, nothing contained in this Section
shall  be  deemed  to grant  any  right to any  Indemnified  Party  which is not
permitted to be granted to an officer,  director or employee of Mergeparty under
the DCL, assuming for such purposes that Mergeparty's  Organic Documents provide
for the maximum indemnification permitted by the DCL.

         (c)  Mergeparty  will cause to be  maintained  for a period of not less
than six (6) years from the Effective  Time  American's  current  directors' and
officers'  insurance and  indemnification  policy to the extent that it provides
coverage for events occurring prior to the Effective Time ("D&O  Insurance") for
all  Persons  who are  directors  and  officers  of American on the date of this
Agreement, so long as the annual premium therefor would not be in excess of 200%
of the last  annual  premium  therefor  paid  prior to the date of the  Original
Merger Agreement (the "Maximum Premium");  provided, however, that if the annual
premiums of such insurance coverage exceed such amount, Mergeparty shall only be
obligated to obtain the greatest coverage available under such policy for a cost
not exceeding such amount,  provided further,  however,  that Mergeparty may, in
lieu of  maintaining  such  existing  D&O  Insurance  as provided  above,  cause
coverage  to be  provided  under  any  policy  maintained  for  the  benefit  of
Mergeparty or any of its Subsidiaries,  so long as the terms thereof are no less
advantageous  to the  intended  beneficiaries  thereof  than  the  existing  D&O
Insurance.  If the existing D&O  Insurance  expires,  is  terminated or canceled
during such six-year period, Mergeparty will use its best efforts to cause to be
obtained as much D&O  Insurance  as can be obtained  for the  remainder  of such
period for an annualized premium not in excess of the Maximum Premium,  on terms
and conditions no less advantageous to the covered Persons than the existing D&O
Insurance.  American  represents to Mergeparty  that the Maximum  Premium is not
greater than $500,000.

         (d) In the event  Mergeparty or  Mergeparty  Subsidiary or any of their
respective  successors or assigns (i) consolidates with or merges into any other
person and shall not be the  continuing  or surviving  corporation  or entity of
such  consolidation or merger or (ii) transfers all or substantially  all of its
properties  and  assets  to any  person,  then  and in each  such  case,  proper
provisions  shall be made so that the  successors  and assigns of  Mergeparty or
Mergeparty  Subsidiary,  as the case may be,  shall assume the  obligations  set
forth in this Section.

         (e) This  Section is  intended  to be for the  benefit of, and shall be
enforceable   by,   the   Indemnified   Parties,   their   heirs  and   personal
representatives  and shall be binding on Mergeparty,  Mergeparty  Subsidiary and
their respective successors and assigns.

         6.13  Solicitation  of  Employees.  If this  Agreement  is  terminated,
Mergeparty  agrees  that  neither  it  nor  any  of its  Subsidiaries  or  other
Affiliates  will,  for a period of  eighteen  (18)  months from the date of such
termination,  solicit  or  actively  seek to hire any key  employees  (including
without limitation any station manager,  sales manager,  program director or any
individual senior to any of such individuals) who during such period is employed
by American or any of its  Subsidiaries,  whether or not such  individual  would
commit breach of such individual's  employment  agreement or contract in leaving
such  employment;  provided,  however,  that the  foregoing  shall  not  prevent
Mergeparty from taking any action permitted by the Confidentiality Agreement.


                                      -33-


<PAGE>

         6.14 Change of Name. Within ten (10) days after the Closing, Mergeparty
shall cause each of its  Subsidiaries,  if necessary,  to file  certificates  of
amendment  with the  appropriate  Secretary of State,  amending  such  company's
Organic  Documents to change the name of such company to any name which does not
include the words "American Radio".  Immediately prior to the Closing,  American
will assign to American  Tower or its  designee all right,  title and  interest,
including all the goodwill related thereto, in and for past infringements of the
name "American Radio" and related trademarks, service marks, logos and the like.
As soon as commercially  practicable,  but in no event later than six (6) months
from the Closing Date,  Mergeparty  Subsidiary and its Subsidiaries  shall cease
all use of the name "American Radio" in all modes.

         6.15  Benefit  Plans.  Mergeparty  shall  take  such  action  as may be
necessary  so  that on and  after  the  Effective  Time  and  for  one (1)  year
thereafter,  officers and employees of American and its Subsidiaries (other than
Tower  Employees)  shall be  provided  employee  benefits,  plans  and  programs
(excluding  equity  incentive  arrangements)  which are no less favorable in the
aggregate than those  generally  available  pursuant to those  employee  benefit
plans and programs in effect for such officers and employees  immediately  prior
to the Effective Time; it being  understood that Mergeparty  shall determine the
types and  levels of  specific  benefits  to be so  provided.  For  purposes  of
eligibility to participate and vesting in all benefits  provided to officers and
employees of American and its Subsidiaries  (other than Tower  Employees),  such
officers and  employees of American and its  Subsidiaries  will be credited with
their years of service with American and its Subsidiaries and prior employers to
the extent  service with American and its  Subsidiaries  and prior  employers is
taken into account under the applicable  plans of American and its  Subsidiaries
as in effect as of the date of the Original Merger  Agreement.  Upon termination
of any health plan of American or any of its Subsidiaries,  individuals who were
officers or  employees of American or its  Subsidiaries  at the  Effective  Time
(other than Tower Employees) shall if employed by Mergeparty or its Subsidiaries
become  eligible to  participate  in such health plans as may be  established or
maintained by Mergeparty or its Subsidiaries to the extent that such individuals
were eligible to participate  in the  applicable  health plan of American or its
Subsidiaries  immediately  prior to the Effective Time.  Amounts paid during the
calendar year in which the Effective Time occurs, but before the Effective Time,
by officers and  employees of American  and its  Subsidiaries  (other than Tower
Employees)  under any health plans of American shall after the Effective Time be
taken into account in applying  deductible and  out-of-pocket  limits applicable
under the health plans of Mergeparty or its  Subsidiaries  provided  during such
calendar  year to the same  extent as if such  amounts  had been paid under such
health plans of Mergeparty or its  Subsidiaries and Mergeparty shall cause to be
waived  under its health  plans any  pre-existing  conditions  as of the date of
termination of the American  health plan and  eligibility to participate in such
health plan to the extent such  conditions  would be waived under the applicable
plans of American and its  Subsidiaries as in effect on the date of the Original
Merger  Agreement.  Nothing in this Agreement  shall be construed as granting to
any  employee  of  American  or  its   Subsidiaries  any  rights  of  continuing
employment.

         6.16 American Cumulative Preferred Stock. To the extent permitted under
Contracts,  pursuant to which any indebtedness for money borrowed of American or
any of its  Subsidiaries  is outstanding  as of the date of the Original  Merger
Agreement, and by the American Preferred Stock, American shall pay all dividends
in respect of the American Cumulative Preferred Stock in cash.

         6.17 American Tower Transaction.  As soon as practicable  following the
execution  of the  Original  Merger  Agreement  and in any  event  prior  to the
consummation  of the  Merger,  American  shall  prepare,  in  consultation  with
Mergeparty  and its  counsel,  the  definitive  documentation  to be executed by
American and American Tower to effect the delivery of the shares of Tower Common
Stock as part of the Tower Merger Consideration or the Merger Consideration,  as
the case may be (the  "Tower  Separation"),  and submit  such  documentation  to
Mergeparty for its approval,  which approval shall not be unreasonably withheld,
delayed
                                      -34-


<PAGE>

or  conditioned  (as  approved,  the "Tower  Documentation"),  and  American and
American Tower shall execute and deliver the Tower  Documentation in the form so
approved.  Mergeparty  and  American  agree that the Tower  Documentation  shall
include or be prepared on a basis consistent with the following:

                  (a)   American   Tower  shall   indemnify,   defend  and  hold
         Mergeparty, American and Subsidiaries of American (other than the Tower
         Subsidiaries,  collectively in this Section the "American Tower Group")
         harmless from and against any  liabilities  to which American or any of
         its  Subsidiaries  (other than the American Tower Group or, in the case
         of  clauses  (B) and (C)  below  of this  paragraph  (a),  any of their
         officers or directors) may be or become subject that relate to or arise
         from the assets,  business,  operations,  debts or  liabilities  of ATS
         Mergercorp or the American  Tower Group (other than, in the case of the
         American  Tower  Group,  income  tax  liabilities),  including  without
         limitation  (i) the assets to be transferred to American Tower pursuant
         to  Section  6.17(f),  (ii)  liabilities  (A) in  connection  with  the
         distribution  of the shares of Tower  Common Stock as part of the Tower
         Merger Consideration or the Merger  Consideration,  as the case may be,
         (B)  relating  to  or  arising  from  any  agreement,   arrangement  or
         understanding  (other  than the Tower  Documentation)  entered  into by
         American,  ATS Mergercorp or any member of the American Tower Group (x)
         for the  benefit  of any member of the  American  Tower  Group,  (y) in
         contemplation of the Tower Separation, or (z) with respect to the sale,
         assignment,  transfer or other  disposition of shares of American Tower
         Common Stock,  (C) relating to or arising from any untrue  statement or
         alleged  untrue  statements of a material  fact  contained in the Proxy
         Statement,  the Tower Proxy Statement, the Registration Statement or in
         any  document  filed or  required  to be filed in  connection  with the
         Merger,  or in any document  filed or required to be filed by American,
         ATS  Mergercorp or any member of the American Tower Group in connection
         with the  preceding  clause (B) or any omission or alleged  omission to
         state  therein  a  material  fact  required  to be  stated  therein  or
         necessary to make the statements therein, in light of the circumstances
         under which they were made,  not  misleading,  except  with  respect to
         information  provided by or relating solely to American  (excluding ATS
         Mergercorp  and the  American  Tower  Group)  which is  contained in or
         expressly  consistent  with the Filed  American  SEC  Documents  or the
         American  September  10-Q,  (iii) any  economic  impact  related  to or
         arising  from the  failure to obtain any  Governmental  Authorizations,
         Private  Authorizations  or other third party consents,  or to make any
         Governmental Filings, necessary to consummate the Tower Separation, and
         (iv) the rental and related  expenses for the  relevant  portion of the
         leased premises located at 116 Huntington Avenue, Boston, Massachusetts
         in the event of the  failure  to obtain the  landlord's  consent to the
         assignment  of the  obligations  relating  to,  or  sublease  of,  such
         relevant portion of such premises.

                  (b)  American  shall  indemnify,  defend and hold the American
         Tower  Group  harmless  from and against  any  liabilities  (other than
         income tax  liabilities)  to which the  American  Tower Group may be or
         become  subject  that  relate to or arise  from the  assets,  business,
         operations, debts or liabilities of American or its Subsidiaries (other
         than the American  Tower Group)  whether  arising prior to,  concurrent
         with or after the Merger.

                  (c) The Tower  Documentation  shall include an agreement  that
         addresses   issues   of  the   allocation   of  Tax   liabilities   and
         deconsolidation  of American and the  American  Tower Group which shall
         contain principles to the following effect:

                           (i) The tax sharing  agreement  among  members of the
                  American  Tower Group and American and its other  Subsidiaries
                  shall be  terminated  as of the  earlier of (x) the  effective
                  date  of  the   Merger,   and  (y)  the   date   (the   "Tower
                  Deconsolidation  Date")  that the  American  Tower Group is no
                  long eligible to be included in the  consolidated  tax returns
                  of American and its other  Subsidiaries under Sections 1501 to
                  1504 of the Code (the "Tower 

                                      -35-


<PAGE>

                  Deconsolidation")  and will  have no  further  effect  for any
                  taxable year  (whether the current  year, a future year,  or a
                  past year).

                           (ii)  American   shall  include  the  income  of  the
                  American Tower Group  (including any deferred income triggered
                  into income by Reg. ss.1.1502-13 and Reg. ss.1.1502-14 and any
                  excess   loss   accounts   taken   into   income   under  Reg.
                  ss.1.1502-19)  on American's  consolidated  federal income Tax
                  returns and  consolidated  or combined  state and local income
                  Tax returns to the extent  such income is properly  includible
                  thereon  for all  periods  through  the Tower  Deconsolidation
                  Date,  and pay any income Taxes  attributable  to such income.
                  American Tower shall reimburse  American for any such federal,
                  state and local income Taxes payable by the American Tax Group
                  attributable  to such  income,  as  determined  on a  separate
                  company basis;  provided,  however,  that American Tower shall
                  have no reimbursement obligation if American has no income Tax
                  liability  on a  consolidated  basis  as  a  result  of a  net
                  operating  loss  or to  the  extent  that  the  income  of the
                  American  Tower Group is offset by a net operating  loss under
                  the principles of clause 6.17(c)(v).  The American Tower Group
                  will  furnish Tax  information  to American  for  inclusion in
                  American's  federal  consolidated  income  Tax  return for the
                  period  through the Tower  Deconsolidation  Date in accordance
                  with American Tower's past custom and practice.  The income of
                  the American  Tower Group will be apportioned to the period up
                  to and including the Tower Deconsolidation Date and the period
                  after the Tower  Deconsolidation  Date by closing the books of
                  the American Tower Group as of the end of such date.

                           (iii) American Tower shall indemnify the American Tax
                  Group and  Mergeparty  for all  Taxes  imposed  by any  Taxing
                  Authority  on any  member  of the  American  Tax  Group  or on
                  Mergeparty (or on any member of its consolidated tax group) as
                  a result  of or in  connection  with the sale or  transfer  of
                  assets to the American Tower Group pursuant to Section 6.17(g)
                  (or  between  members of the  American  Tax Group prior to the
                  final  transfer  to a member of the  American  Tower  Group or
                  between members of the American Tower Group),  the Merger, the
                  Tower Merger,  the Tower Separation,  any other disposition or
                  issuance of stock of American Tower  contemplated or permitted
                  hereby, or the merger of American Tower with any other Person,
                  as the case may be, including without  limitation any Taxes on
                  any gain to any member of the American Tax Group arising under
                  Section 311 of the Code, any Taxes on any deferred gain to any
                  member of the American  Tax Group  triggered as a result of or
                  upon any such event, any gain  attributable to any excess loss
                  account  triggered upon any such event, any Taxes arising as a
                  result of the election or other  transactions  contemplated by
                  clause  6.17(c)(xii),  income or gain  arising  as a result of
                  transactions   described  in  Section  3.4(c)  or  the  second
                  sentence  of Section  6.8(a),  and gain on the  conversion  of
                  American  Convertible  Preferred Stock into Tower Common Stock
                  and any transfer Taxes arising from any such event;  provided,
                  however,  that such  indemnity  shall only apply to the extent
                  that the  additional  liability  for such Taxes payable by the
                  American Tax Group as a consequence  of such events (on a "but
                  for" basis) exceeds $20,000,000.

                           (iv) If, as a result of any payment by American Tower
                  to any  member  of the  American  Tax  Group or to  Mergeparty
                  pursuant to this Section 6.17(c) (including this clause (iv)),
                  Mergeparty  (or  any  member  of its  consolidated  group  for
                  Federal income tax purposes) or any member of the American Tax
                  Group  becomes  liable in any taxable year to pay any Taxes in
                  excess of the Taxes they would have owed in the absence of any
                  such payment by American Tower,  American Tower will indemnify
                  such Person for such Tax  liability and make such Person whole
                  on an after-tax basis for such Tax liability.

                                      -36-


<PAGE>


                           (v) For  the  purposes  of  clauses  6.17(c)(ii)  and
                  (iii), net operating losses of the American Tax Group shall be
                  reduced and deemed  absorbed in the  following  order for each
                  taxable year of the American Tax Group:  first,  by all income
                  unrelated to the  transactions  contemplated by this Agreement
                  of members of the American Tax Group other than members of the
                  American Tower Group for the entire applicable taxable year of
                  the  American  Tax Group;  second,  by income of the  American
                  Tower Group  described in clause  6.17(c)(ii);  and third,  by
                  income  of  the  American  Tax  Group   described  in  Section
                  6.17(c)(iii).  Neither the American  Tax Group nor  Mergeparty
                  (or any member of its  consolidated  group for Federal  income
                  tax  purposes)  shall  have any  claim  under  either  Section
                  6.17(c)(ii) or (iii) for  additional Tax liability  arising in
                  subsequent  taxable years solely as a result of the absorption
                  of net  operating  losses  of the  American  Tax Group in this
                  manner.

                           (vi)  American  shall  control  any audit or  contest
                  relating to Taxes  attributable  to the American Tax Group. To
                  the  extent  such  audit or  contest  relates  to  Taxes  that
                  American Tower is obligated to reimburse or indemnify American
                  under this  agreement,  American  shall (x) regularly  consult
                  with American Tower in connection  with such audit or contest;
                  (y) provide American Tower with periodic reports on the status
                  of such audit or contest;  and (z) not enter into a settlement
                  agreement  relating to such audit or contest  that  materially
                  prejudices American Tower without American Tower's consent.

                           (vii) If pursuant  to any Tax audit or contest  there
                  is an  adjustment  to  any  Taxes  that  are  reimbursable  or
                  indemnifiable by the American Tower Group to any member of the
                  American  Tax Group under this  Agreement,  including  clauses
                  6.17(c)(ii),  (iii) and (iv),  then (x) any  additional  Taxes
                  imposed  on  the  American  Tax  Group  as a  result  of  such
                  adjustment  shall be  indemnified by the American Tower Group;
                  and (y) any refund of Taxes paid to the  American Tax Group as
                  a result of such adjustment of amounts previously  indemnified
                  by  American  Tower  shall be  promptly  paid over to American
                  Tower  (including  additional  amounts to make American  Tower
                  whole on an after-Tax basis, not exceeding amounts  previously
                  paid by American Tower Group with regard to such Taxes).

                           (viii) American Tower shall not have the right to any
                  refund,  credit (or other  reduction) of Taxes realized by the
                  American  Tax  Group   resulting   from  a  carry  back  of  a
                  post-acquisition  Tax  attribute of any of the American  Tower
                  Group into a Tax Return filed by the American Tax Group.

                           (ix) American Tower, American and Mergeparty agree to
                  attempt  in good  faith to  mutually  agree  on such  terms as
                  promptly as  practicable  after the date  hereof.  If American
                  Tower,  American  and  Mergeparty  cannot agree on such terms,
                  then any  disagreement  shall  be  resolved  by an  arbitrator
                  jointly  selected by American Tower,  American and Mergeparty.
                  The arbitrator  shall be a law or accounting  firm  nationally
                  recognized in tax matters. The costs of such arbitration shall
                  be shared equally by American Tower and American. The decision
                  of the arbitrator shall be binding on all parties.

                           (x)  American  shall  not  elect  to  retain  any net
                  operating  loss  carryovers or capital loss  carryovers of the
                  American Tower Group.

                           (xi) The  indemnities  of the  American  Tower  Group
                  described  in  this  Section   6.17(c)   shall  apply  to  all
                  applicable Taxes whenever they shall arise.

  
                                      -37-


<PAGE>

                         (xii) At the  request of any  member of the  American
                  Tower Group,  American  agrees that it shall,  and shall cause
                  its  Subsidiaries  or other  appropriate  Affiliates  to, make
                  and/or  cooperate with members of the American Tower Group (x)
                  in making an election  under  Section  336(e) of the Code with
                  respect  to  the  Tower   Separation,   or  (y)  in  effecting
                  intercompany  sales or exchanges of assets designed to achieve
                  a comparable  effect whereby deferred  intercompany  gains are
                  recognized immediately prior to the Tower Deconsolidation.

                  (d) The Tower  Documentation shall provide that American shall
         obtain all Governmental Authorizations, Private Authorizations or other
         third party  consents,  and make any  necessary  Governmental  Filings,
         necessary to consummate the Tower Separation,  except where the failure
         to obtain such consents, in the aggregate,  would not (i) be reasonably
         likely to have any adverse effect on American,  (ii) materially  impair
         the ability of American to perform its obligations under this Agreement
         or the Tower  Documentation,  or (iii)  materially delay or prevent the
         consummation of the Merger. The Tower  Documentation shall provide that
         the  Tower  Separation  shall  be done in  compliance  with  American's
         certificate  of  incorporation  and by-laws and in material  compliance
         with all Applicable Laws.

                  (e) At the  Effective  Time,  a member of the  American  Tower
         Group shall  assume (i) to the extent  permitted by the  landlord,  the
         obligations  under  the  lease  of  116  Huntington   Avenue,   Boston,
         Massachusetts,  with  respect to the  relevant  portion of such  leased
         premises or, if such permission is not obtained, sublease such relevant
         portion, and (ii) all liabilities with respect to which indemnification
         is provided under Section 6.17(a).  American shall cause all members of
         the  American  Tower Group to be released  from all other  liabilities;
         provided, however, that American Tower agrees to reimburse American for
         any  expenses  incurred in  obtaining  such  release.  American and its
         Subsidiaries  (other than the American  Tower Group) shall  release the
         American  Tower Group from all Claims by  American or its  Subsidiaries
         (other than the American  Tower  Group),  and the American  Tower Group
         shall release  American and its other  Subsidiaries  from all Claims by
         the American  Tower Group,  in each case except for Claims arising from
         or attributable to the  transactions  contemplated by this Agreement or
         any  Collateral  Document or otherwise  asserted prior to the Effective
         Time.

                  (f) Except as  otherwise  provided by Section  6.19,  American
         shall, or shall cause its Subsidiaries  to, as applicable,  contribute,
         transfer or convey to American  Tower the assets  described  in Section
         6.17 of the American  Disclosure  Schedule,  and  American  Tower shall
         assume  all of  American's  and  such  Subsidiaries'  obligations  with
         respect to such assets to the extent so set forth.

                  (g)  The   Tower   Documentation   shall   not   include   any
         representations or warranties by American or American Tower relating to
         the business,  operations, assets, debts or liabilities of American and
         its Subsidiaries  (other than the American Tower Group) or the American
         Tower Group.

                  (h) On the Closing Date,  the employees of American  listed in
         Section  6.17  of  the  American   Disclosure   Schedule   (the  "Tower
         Employees") shall be offered full-time  employment by American Tower or
         one of its Subsidiaries.  Effective  immediately prior to the Effective
         Time,  American  Tower shall assume all  obligations  arising under any
         Plan or Benefit Arrangement between American or any of its Subsidiaries
         and the Tower  Employees  other than the  rights,  if any, of the Tower
         Employees  with  respect  to the  American  Options  (which  are  being
         satisfied  by American as  provided  in Section  6.8) and all  existing
         rights to indemnification. Such assumption agreement shall provide that
         American and its Subsidiaries, effective as of the Effective Time shall
         be  indemnified by

                                      -38-


<PAGE>

         American  Tower from all  obligations  arising  under  such  employment
         agreements or  arrangements  (except in respect of any American  Option
         which is not converted  into an option to acquire Tower Common Stock in
         accordance  with the  provisions  of Section  6.8(b)  and all  existing
         rights  to  indemnification).  For a period  of  eighteen  (18)  months
         following the consummation of the Merger, members of the American Tower
         Group  shall not  actively  solicit  or seek to hire any  employees  of
         American  or its  Subsidiaries  not  currently  engaged  in  the  Tower
         Business,  other  than the Tower  Employees,  it being  understood  and
         agreed that such  agreement  shall not be deemed to prevent  members of
         the  American  Tower  Group  from  placing  general  advertisements  in
         publications or on the Internet or soliciting any such employee who (i)
         initiates  employment  discussions  with a member of the American Tower
         Group or (ii) is not employed by American or Mergeparty or any of their
         respective  Subsidiaries  on the date such a member first solicits such
         employee.

                  (i) At the  request  of  American  Tower  and  subject  to the
         requirements  and  restrictions  imposed  on  American  by  any  of its
         financing  documents (as from time to time  amended),  American  shall,
         from time to time after the date of the Original  Merger  Agreement and
         prior to the  Effective  Time,  permit  American  Tower to (i)  acquire
         (whether by merger, stock or asset acquisition or otherwise) additional
         businesses  engaged in the business in which American Tower is engaged,
         (ii) construct  additional  communication  towers,  or (iii) make other
         capital improvements on assets owned or leased by American Tower or its
         Subsidiaries,   and  in  each  such  case   make   additional   capital
         contributions  in American  Tower,  or make loans to American Tower, of
         the funds.

                  (j) The indemnification  and other obligations  referred to in
         this Section shall survive the consummation of the Merger.

                  (k) The Tower  Documentation  shall  provide that prior to the
         Effective  Time,  American  shall amend (i) its Section  401(k) Plan to
         permit a transfer of the assets held  thereunder for the benefit of the
         Tower  Employees to a Section 401(k) Plan to be established by American
         Tower  and,  prior  to the  Effective  Time,  such  assets  will  be so
         transferred  (along with any outstanding  qualified  domestic relations
         orders and loans) and (ii) any other  Benefit  Plan  arrangements  with
         respect to Tower Employees to reflect the Merger.

                  (l) The Tower  Documentation  shall  provide that prior to the
         Effective Time American shall,  to the extent  requested by Mergeparty,
         cause the  American  Tower Group to perform its  obligations  under the
         Tower Documentation.

                  (m) Mergeparty  shall,  at the written  request of American in
         its sole and absolute discretion,  immediately prior to the Merger, and
         subject  to  the   satisfaction   of  all  of  the  conditions  to  the
         consummation of the  transactions  contemplated  hereby,  purchase,  at
         their  then  fair  market  value,  shares  of a new  class of  American
         preferred stock that constitutes "Junior Securities" (as defined in the
         American  Cumulative  Preferred Stock) in an amount (which shall not in
         the aggregate  exceed  $200,000,000)  necessary to enable (i) the Tower
         Stock  Consideration  to be  delivered  to the  holders  of  shares  of
         American Common Stock and holders of American  Options  pursuant to the
         Merger,  and (ii) Tower Common Stock to be delivered upon conversion of
         the American Convertible  Preferred Stock, without causing any conflict
         with,  or breach or  violation  of, or default  under,  or creating any
         right to  accelerate  any  obligation  or  liability  in, or causing or
         creating any of the foregoing  after the giving of notice or passage of
         time or both with, of, under or in any  indebtedness of American or the
         American Cumulative Preferred Stock;  provided,  however, that anything
         in  this  Section  or  elsewhere  in  this  Agreement  to the  contrary
         notwithstanding,  in such  event such new class of  American  preferred
         stock shall remain  outstanding  immediately  following  the  Effective
         Time.
 
                                      -39-


<PAGE>

                 (n) The Tower  Documentation shall provide that American shall
         cause American  Tower to file with, and cause to be declared  effective
         under the Securities Act prior to the Effective Time by, the Commission
         a  registration  statement  to permit the  delivery  of shares of Tower
         Common  Stock by  American  upon  conversion  of  American  Convertible
         Preferred  Stock following the Effective Time under the Securities Act.
         Such Tower  Documentation  shall further  provide that  American  Tower
         shall  maintain,   on  customary  terms,  the   effectiveness  of  such
         registration  statement  under the  Securities  Act until  such time as
         American  Tower shall  deliver to American an opinion of legal  counsel
         reasonably   satisfactory   to  American  and   Mergeparty   that  such
         registration statement is no longer required to permit such delivery in
         accordance with the Securities Act.

         6.18 Purchase  Price  Adjustment.  (a) Within 90 days after the Closing
Date,  Mergeparty shall prepare and deliver to American Tower (i) a consolidated
balance sheet (the  "Closing  Balance  Sheet") of American and its  Subsidiaries
(other  than  the  Tower  Subsidiaries)  (the  "Post-Closing  American  Group"),
prepared from the books and records of the Post-Closing American Group, and (ii)
a statement  (the "Closing  Statement")  setting  forth (A) Working  Capital (as
defined below) as of the Effective Time ("Closing  Working Capital") and (B) Net
Debt (as defined below) as of the Effective Time ("Closing Net Debt"),  together
with a certificate  of  Mergeparty's  chief  financial  officer that the Closing
Statement has been prepared in accordance with this Section 6.18.

         During the 45-day  period  following  American  Tower's  receipt of the
Closing Statement,  American Tower shall be permitted to review (and make copies
of) the working  papers of  Mergeparty  relating to the Closing  Statement.  The
Closing  Statement  shall  become  final and  binding  upon the  parties  on the
forty-sixth day following delivery thereof,  unless American Tower gives written
notice of its disagreement with the Closing Statement ("Notice of Disagreement")
to Mergeparty  prior to such date. Any Notice of Disagreement  shall (i) specify
in  reasonable  detail the nature of any  disagreement  so  asserted,  (ii) only
include  disagreements  based on Closing Working Capital or Closing Net Debt (or
the  components  thereof) not being  calculated in accordance  with this Section
6.18 and  (iii) be  accompanied  by a  certificate  of  American  Tower's  chief
financial  officer  that he or she concurs with each of the  positions  taken by
American Tower in the Notice of  Disagreement.  If a Notice of  Disagreement  is
received  by  Mergeparty  in a timely  manner,  then the Closing  Statement  (as
revised in accordance with clause (A) or (B) immediately following) shall become
final and binding on the earlier of (A) the date  Mergeparty  and American Tower
resolve  in  writing  any  differences  they have with  respect  to the  matters
specified in the Notice of Disagreement or (B) the date any disputed matters are
finally resolved in writing by the Accounting Firm (as defined below).

         During  the  30-day   period   following   delivery   of  a  Notice  of
Disagreement,  Mergeparty and American Tower shall seek in good faith to resolve
in  writing  any  differences  which they may have with  respect to the  matters
specified in the Notice of  Disagreement.  During such period  Mergeparty  shall
have access to (and shall be permitted to make copies of) the working  papers of
American Tower prepared in connection  with the Notice of  Disagreement.  At the
end of such 30-day  period,  Mergeparty  and  American  Tower shall submit to an
independent  accounting firm (the  "Accounting  Firm") for review and resolution
any and all matters which remain in dispute and which were properly  included in
the Notice of  Disagreement  and each of  Mergeparty  and  American  Tower shall
submit a  memorandum  setting  forth in  reasonable  detail  the  basis  for its
positions.  The  Accounting  Firm shall be a nationally  recognized  independent
public  accounting firm agreed upon by Mergeparty and American Tower in writing.
Mergeparty and American Tower shall jointly use all reasonable  efforts to cause
the  Accounting  Firm to render a decision  within  thirty  (30) days  following
submission or as promptly thereafter as is practicable.  Mergeparty and American
Tower  agree  that  judgment  may  be  entered  upon  the  determination  of the
Accounting  Firm in any court having  jurisdiction  over the party against which
such  determination  is to be  enforced.  The  cost  of any  dispute  resolution
(including the fees and expenses of

                                      -40-


<PAGE>

the Accounting  Firm and  reasonable  attorney fees and expenses of the parties)
pursuant to this Section 6.18 shall be borne by Mergeparty and American Tower in
inverse  proportion  as they may prevail on matters  resolved by the  Accounting
Firm, which proportionate allocations shall also be determined by the Accounting
Firm at the time the  determination  of the  Accounting  Firm is rendered on the
merits of the matters submitted.

         (b) Subject to Section 6.18(d), if Closing Working Capital is less than
(i)  $60,000,000  in the event the Closing Date is on or prior to March 31, 1998
or (ii)  $70,000,000  in the event the Closing Date is after March 31, 1998 (the
"WC Amount"),  American Tower shall,  and if Closing  Working Capital is greater
than  the WC  Amount,  Mergeparty  shall,  owe  the  other  the  amount  of such
difference.   The  term  "Working  Capital"  shall  mean  Current  Assets  minus
Liabilities  (in each case as defined  below).  The terms  "Current  Assets" and
"Liabilities"  shall mean the current assets and liabilities of the Post-Closing
American Group  calculated in accordance  with GAAP except that (i)  outstanding
principal amount of indebtedness  and liquidation  preference of preferred stock
shall be excluded,  (ii) cash shall be excluded,  (iii) accruals for Taxes shall
be included,  except that (A) Tax liabilities  which American Tower is obligated
to indemnify American and its Subsidiaries (other than the American Tower Group)
pursuant to the provisions of the Tower  Documentation,  and deferred income Tax
assets and liabilities that exist or arise from differences in basis for Tax and
financial  reporting  purposes  attributable  to  acquisitions,   exchanges  and
dispositions  or attributable to  depreciation  and  amortization,  shall not be
taken into account,  (B) Tax benefits  arising from the exercise or cancellation
of options between the date of the Original  Merger  Agreement and the Effective
Time shall not be taken into  account,  and (C) accruals  for Taxes  relating to
acquisitions,  exchanges or dispositions  shall be determined in accordance with
American's past accounting practices,  (iv) Current Assets shall be increased by
an amount  equal to the sum of (x) the amount  derived by  multiplying  the Cash
Consideration  by the  number of shares of  American  Common  Stock  held in its
treasury as of the Effective Date and (y) the aggregate  amount of the spread of
$44.00 over the exercise price of each American  Option  outstanding on the date
of the Original Merger Agreement  terminated or cancelled prior to the Effective
Time or for which the holder has  elected to receive an option to acquire  Tower
Common Stock in lieu thereof, less the Tax benefit that would have been received
with respect to the exercise of such  options,  (v) Current  Assets shall be (A)
increased  (if the  number of shares of  American  Common  Stock  issuable  upon
conversion of the American  Convertible  Preferred Stock is fewer than 3,750,000
(or if the Tower Merger Effective Time shall have occurred, 3,750,000 multiplied
by the American  Conversion  Fraction)) by an amount equal to the amount derived
by multiplying the Cash  Consideration by the excess of (I) 3,750,000 (or if the
Tower Merger  Effective  Time shall have occurred,  3,750,000  multiplied by the
American Conversion  Fraction) less (II) the number of shares of American Common
Stock issuable upon  conversion of the American  Convertible  Preferred Stock or
(B)  decreased (if the number of shares of American  Common Stock  issuable upon
conversion of the American Convertible Preferred Stock is greater than 3,750,000
(or if the Tower Merger Effective Time shall have occurred, 3,750,000 multiplied
by the American Conversion Fraction) by an amount equal to the amount derived by
multiplying  the Cash  Contribution by the excess of (I) the number of shares of
American  Common Stock  issuable  upon  conversion  of the American  Convertible
Preferred Stock less (II) 3,750,000 (or if the Tower Merger Effective Time shall
have occurred,  3,750,000 multiplied by the American Conversion Fraction),  (vi)
liabilities  from the radio  broadcasting  rights  contracts  for St. Louis Rams
games shall be limited to $3,300,000 and (vii) amounts owed by American Tower to
American  pursuant to Section 9.3(b) shall be excluded from Current Assets,  and
liabilities of American,  if any, with respect to such amounts shall be excluded
from Liabilities (it being understood that neither American nor Mergeparty shall
be responsible for any such liabilities).

         (c) Subject to Section 6.18(d), if Closing Net Debt is greater than the
Debt Amount (as defined  below) minus  $50,419,000,  minus cash  received by the
Post-Closing  American Group in respect of options exercised between the date of
the Original Merger Agreement and the Effective Time (the "CD Amount"), American
Tower  shall,  and if Closing  Net Debt is less than the CD  Amount,  Mergeparty
shall,  owe the other the amount of such  difference.  "Debt  Amount" shall mean
$1,066,721,000,  minus the  consideration  that was  

                                      -41-


<PAGE>

expected to be paid (as set forth on Section 6.10(a) of the American  Disclosure
Schedule) with respect to all  acquisitions  set forth in Section 6.10(a) of the
American  Disclosure  Schedule which were not  consummated  prior to the Closing
Date, plus the  consideration  that was expected to be received (as set forth in
Section  6.10(a)  of the  American  Disclosure  Schedule)  with  respect  to all
dispositions  set forth in Section 6.10(a) of the American  Disclosure  Schedule
which were not  consummated  prior to the Closing Date,  plus the  consideration
paid in connection with acquisitions consummated prior to the Closing Date which
were not listed in Section 6.10(a) of the American  Disclosure  Schedule,  minus
the consideration received in connection with dispositions  consummated prior to
the  Closing  Date  which were not  listed in  Section  6.10(a) of the  American
Disclosure Schedule. The term "Net Debt" shall mean outstanding principal amount
of indebtedness  (including,  without  duplication,  guarantees of indebtedness)
plus outstanding  liquidation  preference of all preferred stock (other than the
American Convertible Preferred Stock) minus cash.

         (d) Amounts owed pursuant to the first sentence of Section  6.18(b) and
the first sentence of 6.18(c) shall be aggregated or netted, as appropriate (the
resulting  amount,  the "Adjustment  Amount").  In the event that the Adjustment
Amount minus $10,000,000 is greater than $0 (the "Final Adjustment Amount"), the
party that owes the Final Adjustment  Amount shall make payment by wire transfer
of immediately  available  funds of the Final  Adjustment  Amount  together with
interest  thereon at a rate of interest equal to the lesser of (i) 10% per annum
and (ii) if  American  Tower is being  charged a rate of interest by a financial
institution,  such rate,  but in not event lower than the prime rate as reported
in the Wall Street Journal on the date the Closing  Statement  becomes final and
binding on the  parties,  calculated  on the basis of the actual  number of days
elapsed  divided  by 365,  from  the date of the  Effective  Time to the date of
actual payment.

         (e) The scope of the disputes to be resolved by the Accounting  Firm is
limited to whether the Closing  Statement  was prepared in  compliance  with the
requirements  of this  Section 6.18 and the  allocation  of the costs of dispute
resolution, and the Accounting Firm is not to make any other determination.

         (f)  During  the  period of time from and  after  the  delivery  of the
Closing  Statement  to American  Tower  through  the date the Closing  Statement
becomes final and binding on Mergeparty, American and American Tower, Mergeparty
shall cause the Post-Closing  American Group to afford to American Tower and any
accountants,  counsel  or  financial  advisors  retained  by  American  Tower in
connection  with the  adjustment  contemplated  by this Section 6.18  reasonable
access (with the right to make copies) during normal business hours to the books
and records of the  Post-Closing  American  Group to the extent  relevant to the
adjustment contemplated by this Section 6.18.

         (g) Any  adjustment  pursuant to this  Section 6.18 shall be taken into
account in the calculation of Tax liability pursuant to clause 6.17(c)(iii), and
any  increase  or  decrease  in the  amount of Taxes  that are  reimbursable  or
indemnifiable  by the  American  Tower Group as a result of any such  adjustment
shall be treated as an adjustment to Taxes for purposes of clause 6.17(c)(vii)

         6.19 Tower Leases. In connection with the Tower Separation,  Mergeparty
and American shall agree on the definitive  documentation ("Tower Leases") to be
executed by American  and American  Tower with  respect to certain  broadcasting
towers  set  forth in  Section  6.17(i)  of the  American  Disclosure  Schedules
("Towers").  The markets in which such Towers are located and the annual "market
price" for each  antenna  are set forth in Exhibit  "B."  Except as set forth in
Section 6.17(i) of the American Disclosure  Schedule,  such Towers are now owned
or leased by American and shall become the property of American  Tower.  Each of
the Tower Leases shall contain  standard and customary  terms and conditions and
Mergeparty and American  specifically agree to the inclusion of the following in
each of the Tower Leases:

                                      -42-


<PAGE>


                  (a) except as  provided  in clause  (b) below with  respect to
         those Tower Leases set forth in Section 6.19 of the American Disclosure
         Schedule,  each Tower  Lease  shall be for a term of twenty  (20) years
         with four (4) renewal periods of five (5) years each, each such renewal
         to be upon the same terms and conditions as the original Tower Lease;

                  (b) Prior to the Effective  time,  American shall use its best
         efforts to extend  the term of each lease set forth in Section  6.19 of
         the American  Disclosure Schedule ("Land Leases") to a minimum duration
         of twenty (20) years, inclusive of renewal periods, if any, and provide
         Mergeparty  with  respect to the Towers  subject to the  extended  Land
         Leases,  tower leases with the equivalent benefits set forth in clauses
         (c),  (d) and (e) and for a  minimum  duration  of  twenty  (20)  years
         ("Extended Tower Leases").  With respect to any such Land Lease that is
         not so extended  (except with  respect to the Land Lease for  KUFX(FM),
         which present term of approximately eighteen (18) remaining years shall
         be deemed to satisfy the foregoing requirement of a minimum duration of
         twenty (20)  years),  American,  American  Tower and  Mergeparty  shall
         negotiate  in good  faith to agree  upon  definitive  documentation  to
         provide  Mergeparty  with  respect to the  Towers  subject to such Land
         Leases,  tower leases with the  benefits  equivalent  of such  Extended
         Tower Leases or mutually agreed to alternative  arrangements  providing
         equivalent value to Mergeparty;

                  (c) each Tower Lease shall  provide that no payments  shall be
         payable  by  Mergeparty  for a  period  of  three  (3)  years  from the
         Effective  Time;  for the next three (3) years the payments shall be as
         follows:  one-third (1/3) of the market price as set forth in Exhibit B
         corresponding  to each FM antenna (or AM/FM antenna) for year four (4);
         two-thirds  (2/3) for year five (5) and full market  price for year six
         (6); thereafter,  for the balance of the term and any renewals thereof,
         the  payments  shall  be the  market  price,  together  with an  annual
         increase  every  year,  beginning  for year seven (7), of the lesser of
         five percent (5%) or the Consumer  Price Index for all Urban  Consumers
         over the  previous  year's  payments  (except  with respect to San Jose
         (KUFX)  and  Boston  (WNFT)  which  such  payments  shall  begin at the
         Effective Time,  with respect to Mergeparty,  and will begin on January
         1, 1998 as between  American and American Tower).  Notwithstanding  the
         foregoing,  Mergeparty  acknowledges  that Tower Lease  payments at the
         full  "market  price"  indicated  on Exhibit B by  American to American
         tower may commence  upon such leases  becoming the property of American
         Tower and shall continue until the Effective Time;

                  (d)  all  expenses  for  taxes,  insurance,   maintenance  and
         utilities in respect of each Tower shall be paid by American Tower; and

                  (e)   American   Tower   will   assume  the   obligation   and
         responsibility  for complying  with all  Applicable Law with respect to
         the Towers.

         6.20  Affiliates  of American.  American  shall use its best efforts to
cause each principal executive officer,  each director and each other person who
is an  "affiliate" of American for purposes of Rule 145 under the Securities Act
at the times each of this Agreement and the Tower Merger  Agreement is submitted
for a vote of the  holders  of shares of  American  Common  Stock to  deliver to
American Tower on or prior to the Effective Time and the Tower Merger  Effective
Time, respectively,  a written agreement (an "Affiliate Agreement"),  reasonably
satisfactory  in form,  scope and substance to American and  Mergeparty,  to the
effect that such Person will not offer to sell,  assign,  transfer or  otherwise
dispose of any shares of Tower  Common  Stock  issued in the Merger or the Tower
Merger,  as the case may be,  except,  in each case,  pursuant  to an  effective
registration  statement  or in  compliance  with Rule 145,  or in a  transaction
which, in the opinion of legal counsel  reasonably  satisfactory to American and
Mergeparty, is exempt from the registration requirements of the Securities Act.


                                      -43-


<PAGE>


                                    ARTICLE 7

                               CLOSING CONDITIONS

         7.1 Conditions to  Obligations of Each Party to Effect the Merger.  The
respective  obligations  of each  party to effect the  Merger  shall,  except as
hereinafter provided in this Section, be subject to the satisfaction at or prior
to the  Closing  Date of the  following  conditions,  any or all of which may be
waived, in whole or in part, to the extent permitted by Applicable Law:

                  (a) the Required Vote shall have been obtained;

                  (b) the FCC shall have issued the FCC Order (as defined below)
         approving the  applications  for transfer of control of American's  FCC
         Licenses in connection with the transactions  contemplated  herein, and
         the FCC Order  shall  have been  obtained  without  the  imposition  of
         conditions  that would have a Material  Adverse Effect on  Mergeparty's
         television  and radio  broadcasting  business;  provided  that  without
         triggering   Mergeparty's   right  to  approve   such   conditions   or
         restrictions,  the FCC  Order  (i) may  condition  consummation  of the
         Merger  on  Mergeparty  complying  with the  numerical  limits on local
         multiple  radio  ownership  imposed  by 47  C.F.R.  ss.  73.3555(a)  by
         affording  Mergeparty a period of at least six (6) months following the
         Effective Time within which to comply with such rule through the use of
         divestiture  trusts  on  terms  and  conditions  required  by the  FCC,
         provided  further,  however,  that to the extent that the FCC authority
         for such divestiture  trusts provides for a period of less than six (6)
         months, (A) American has the right to postpone the Effective Time (and,
         to the extent necessary,  the Termination  Date), so that Mergeparty is
         afforded the six (6) month divestiture period,  whether before or after
         the  Effective   Time  and  (B)  if  American   exercises  such  right,
         Mergeparty's  right to approve such  condition  shall not be triggered,
         and (ii) may grant Mergeparty temporary, rather than permanent, waivers
         of the  "one-to-a-market"  rule, 47 C.F.R. ss.  73.3555(c),  so long as
         such  temporary  waivers  shall remain in effect until at least six (6)
         months  following  the  effective  date of FCC  action  concluding  the
         ongoing  rulemaking  proceeding  in MM Docket  Nos.  91-221,  87-8 (FCC
         94-322) or a successor rulemaking proceeding pending at the time of the
         grant of the FCC Order, that considers the "one-to-a-market"  rule. The
         "FCC Order" shall be an action by the FCC approving the transfer of the
         American FCC Licenses with respect to which, except as may be waived in
         writing by Mergeparty in its sole discretion, (i) no timely request for
         stay,  petition for  reconsideration  or appeal or sua sponte action of
         the  FCC  with  comparable  effect  is  pending,  or (ii) if any of the
         foregoing  is  pending,  in the  judgment  of  Mergeparty  it lacks any
         substantial merit or is contrary to established FCC precedent, or (iii)
         if it were to be so  granted,  it  would  not have a  Material  Adverse
         Effect on Mergeparty's  television and radio broadcasting business; and
         as to which the thirty (30) day time period  specified in 47 U.S.C. ss.
         405(a) for  initiating a petition for  reconsideration  of the grant of
         the FCC Order has expired;

                  (c) no Authority of competent jurisdiction shall have enacted,
         issued,  promulgated,  enforced or entered any Law (whether  temporary,
         preliminary or permanent) that remains in effect and restrains, enjoins
         or otherwise prohibits consummation of the Merger; and

                  (d) the waiting period  applicable to the  consummation of the
         Merger  under the Hart-  Scott-Rodino  Act shall  have  expired or been
         terminated.

                                      -44-


<PAGE>

         7.2  Conditions  to  Obligations  of  Mergeparty.   The  obligation  of
Mergeparty  and  Mergeparty  Subsidiary to effect the Merger shall be subject to
the satisfaction of the following conditions, any or all of which may be waived,
in whole or in part, to the extent permitted by Applicable Law:

                  (a) American shall have furnished Mergeparty, with an opinion,
         dated the  Closing  Date of Dow,  Lohnes &  Albertson,  FCC counsel for
         American, substantially in the form attached hereto as Exhibit C;

                  (b) (i) the  representations  and  warranties  of American set
         forth in this Agreement (other than in Sections 4.1(e),  4.11 and 4.13)
         shall  be  true  and  correct  as of the  date of the  Original  Merger
         Agreement  and as of the  Closing  Date as though made on and as of the
         Closing  Date  except  (x)  to  the  extent  such  representations  and
         warranties  expressly  speak as of an earlier  date (in which case such
         representations  and  warranties  shall be true and  correct as of such
         earlier  date)  and  (y)  to  the  extent  that  the  failure  of  such
         representations and warranties to be true and correct,  individually or
         in the aggregate, would not have a Material Adverse Effect on American;
         provided,   however,   that  for  the   purpose  of  this  clause  (y),
         representations  and  warranties  that are qualified as to  materiality
         (including  by  reference to "Material  Adverse  Effect")  shall not be
         deemed to be so qualified,  and (ii) the representations and warranties
         of  American  set  forth  in  Sections  4.1(e),  4.11  and 4.13 of this
         Agreement shall be true and correct in all material  respects as of the
         date of the Original Merger Agreement and as of the Closing Date; and

                  (c) American shall have performed in all material respects all
         obligations  required to be performed by it under this  Agreement at or
         prior to the Closing Date;

                  (d) between the date of the Original Merger  Agreement and the
         Closing Date,  except as contemplated by this Agreement,  and except as
         set forth in Section 4.3 of the  American  Disclosure  Schedule,  there
         shall not have occurred and be continuing  any Material  Adverse Change
         in American.

         7.3 Conditions to  Obligations of American.  The obligation of American
to effect the  Merger  shall be subject  to the  satisfaction  of the  following
conditions,  any or all of which  may be  waived,  in  whole or in part,  to the
extent permitted by Applicable Law:

                  (a) the representations and warranties of Mergeparty set forth
         in this  Agreement  shall  be true  and  correct  as of the date of the
         Original Merger  Agreement and as of the Closing Date as though made on
         and  as  of  the   Closing   Date   except  (x)  to  the  extent   such
         representations  and warranties  expressly  speak as of an earlier date
         (in which case such  representations  and warranties  shall be true and
         correct as of such earlier date) and (y) to the extent that the failure
         of  such  representations  and  warranties  to  be  true  and  correct,
         individually  or in the  aggregate,  would not have a Material  Adverse
         Effect on Mergeparty;  provided,  however, that for the purpose of this
         clause (y),  representations  and  warranties  that are qualified as to
         materiality (including by reference to "Material Adverse Effect") shall
         not be deemed to be so qualified.; and

                  (b) Mergeparty  shall have performed in all material  respects
         all obligations  required to be performed by it under this Agreement at
         or prior to the Closing Date.


 
                                      -45-


<PAGE>


                                   ARTICLE 8

                        TERMINATION, AMENDMENT AND WAIVER

         8.1 Termination.  This Agreement may be terminated at any time prior to
the Closing  Date,  whether  before or after receipt by American of the Required
Vote:

                  (a) by mutual  written  consent of  American,  Mergeparty  and
         Mergeparty Subsidiary;

                  (b) by either  Mergeparty  or  American  if any  Authority  of
         competent  jurisdiction  shall  have  enacted,   issued,   promulgated,
         enforced  or  entered  any  Law  that  shall  have  become   final  and
         nonappealable  and  that  restrains,  enjoins  or  otherwise  prohibits
         consummation  of the Merger,  unless the party seeking such  restraint,
         injunction or prohibition or any Affiliate  thereof was the terminating
         party;

                  (c) by either  Mergeparty  or American if the Merger shall not
         have been consummated by the Termination Date for any reason; provided,
         however,  that the right to terminate this Agreement under this Section
         8.1(c)  shall not be  available to any party whose action or failure to
         act (or the  action  or  failure  to act of any  Affiliate)  has been a
         principal cause of or resulted in the failure of the Merger to occur on
         or before  such date and such  action or failure to act  constitutes  a
         breach of this Agreement;

                  (d) by either  Mergeparty  or  American if the  Required  Vote
         shall not have been obtained at the American  Stockholders Meeting duly
         convened  therefor or at any adjournment or postponement  thereof or by
         written consent;

                  (e) by American  in the event (i)  American is not in material
         breach of this Agreement and none of its  representations or warranties
         shall have been or become  and  continue  to be untrue in any  material
         respect, and (ii) Mergeparty is in material breach of this Agreement or
         any of its representations or warranties shall have become and continue
         to be untrue in any manner  that would cause the  condition  in Section
         7.3(a) not to be satisfied,  and such a breach or untruth exists and is
         not capable of being cured by and will prevent or delay consummation of
         the Merger by or beyond the Termination Date; or

                  (f)  by  Mergeparty  in the  event  (i)  Mergeparty  is not in
         material  breach of this Agreement and none of its  representations  or
         warranties  shall have been or become and  continue to be untrue in any
         material  respect,  and (ii)  American  is in  material  breach of this
         Agreement or any of its representations or warranties shall have become
         and continue to be untrue in any manner that would cause the  condition
         in  Section  7.2(b) not to be  satisfied,  and such a breach or untruth
         exists and is not capable of being  cured by and will  prevent or delay
         consummation of the Merger by or beyond the Termination Date.

The term "Termination  Date" shall mean December 31, 1998, as such date may from
time to time be extended  pursuant  to the  provisions  of Section  7.1(b) or by
mutual agreement of the parties.

         The  right of  Mergeparty  or  American  to  terminate  this  Agreement
pursuant to this  Section  shall remain  operative  and in full force and effect
regardless of any investigation made by or on behalf of either party, any Person
controlling any such party or any of their respective  Representatives,  whether
prior to or after the execution of this Agreement.

 
                                      -46-


<PAGE>

         8.2 Effect of Termination.

         Except  as   provided  in   Sections   6.1   (Access  to   Information;
Confidentiality),  6.3 (Public Announcements), and 9.3 (Fees, Expenses and other
Payments) and this Section,  in the event of the  termination  of this Agreement
pursuant  to  Section  8.1,  or in the event the  Merger  shall not have  become
effective prior to the end of business on the day prior to the Termination Date,
this  Agreement  shall  forthwith  become  void and have no effect,  without any
liability  on the  part of any  party,  or any of its  respective  stockholders,
officers or directors,  to the other;  provided,  however, that such termination
shall  not  relieve  any  party  from  liability  for any  breach  of any of its
warranties,  covenants or agreements set forth in this Agreement and,  provided,
however that such termination will not terminate the Confidentiality Agreement.


                                    ARTICLE 9

                               GENERAL PROVISIONS

         9.1  Amendment.  This Agreement may be amended from time to time by the
parties  hereto at any time prior to the Closing Date but only by an  instrument
in writing signed by the parties hereto and, after receipt of the Required Vote,
subject, in the case of American, to Applicable Law.

         9.2 Waiver. At any time prior to the Closing Date, except to the extent
not permitted by Applicable Law, Mergeparty or American may, either generally or
in a particular instance and either  retroactively or prospectively,  extend the
time for the  performance of any of the  obligations or other acts of the other,
subject,  however,  to the provisions of Section 8.1, waive any  inaccuracies in
the  representations  and  warranties  of the other  contained  herein or in any
document  delivered  pursuant hereto, and waive compliance by the other with any
of the agreements,  covenants,  conditions or other provision  contained herein.
Any such  extension or waiver shall be valid only if set forth in an  instrument
in writing signed by the party or parties to be bound thereby.

         9.3 Fees, Expenses and Other Payments. (a) Subject to the provisions of
paragraph (b) of this Section 9.3, all costs and expenses incurred in connection
with any filing fees (including without limitation Hart-Scott-Rodino Act filings
and FCC filing fees),  transfer  Taxes,  sales Taxes,  document  stamps or other
charges levied by any Authority in connection with this Agreement and the Merger
shall be borne equally by Mergeparty  and  American.  Subject as aforesaid,  all
other  costs  and  expenses   incurred  in  connection  with  the   negotiation,
preparation,  performance and enforcement of this Agreement  (including all fees
and expenses of counsel, financial advisors, accountants, and other consultants,
advisors and  representatives  for all  activities  of such  persons  undertaken
pursuant  to this  Agreement)  incurred by the  parties  hereto,  shall be borne
solely and  entirely by the party which has  incurred  such costs and  expenses,
except  to the  extent,  if  any,  otherwise  specifically  set  forth  in  this
Agreement.

         (b) Promptly following the Effective Time,  American Tower shall pay to
American in immediately available funds (and make American whole on an after-tax
basis under the principles set forth in Section  6.17(c)(iv)) an amount equal to
the aggregate  costs and expenses  incurred by American in  connection  with any
agreement,  arrangement or  understanding  (other than the Tower  Documentation)
entered into by American,  ATS  Mergercorp  or any member of the American  Tower
Group following the date of the Original Merger Agreement (x) for the benefit of
any  member of the  American  Tower  Group,  (y) in  contemplation  of the Tower
Separation or (z) in  connection  with the sale,  assignment,  transfer or other
disposition  of  shares  of  American  Tower  Common  Stock,  including  without
limitation such costs and expenses  incurred by American to Merrill Lynch Pierce
Fenner & Smith Incorporated and any such costs and expenses

                                      -47-


<PAGE>

 incurred by American
to CSFB in excess of those set forth in the engagement  letter between  American
and CSFB provided by American to  Mergeparty in accordance  with Section 4.14 of
the Original Merger Agreement.

         (c) In the  event  that  this  Agreement  is  terminated  by any  party
pursuant to 8.1(d),  American shall promptly, but in no event later than two (2)
days  after  the date of such  termination,  pay  Mergeparty  a fee equal to $35
million in immediately  available  funds,  plus Expenses.  "Expenses" shall mean
reasonable and reasonably documented out-of-pocket fees and expenses incurred or
paid by or on  behalf  of  Mergeparty  in  connection  with  the  Merger  or the
consummation  of  any  of  the  transactions  contemplated  by  this  Agreement,
including all fees and expenses of counsel, commercial banks, investment banking
firms, accountants, experts and consultants to Mergeparty in an aggregate amount
not to exceed $5 million.

         9.4  Notices.  All  notices  and  other  communications  which  by  any
provision of this Agreement are required or permitted to be given shall be given
in writing  and shall be (a) mailed by  first-class  or  express  mail,  postage
prepaid, or by recognized courier service, (b) sent by telecopy or other form of
rapid  transmission,  confirmed  by mailing  (by first  class or  express  mail,
postage  prepaid,  or by recognized  courier  service)  written  confirmation at
substantially  the  same  time as such  rapid  transmission,  or (c)  personally
delivered to the receiving  party (which if, other than an individual,  shall be
an officer or other responsible party of the receiving party).  All such notices
and communications shall be mailed, sent or delivered as follows:

         (a) If to Mergeparty:

               CBS Corporation
               11 Stanwix Street
               Pittsburgh, Pennsylvania  15222
               Attention:  Louis J. Briskman, Esq.
               Telecopier No.:  (412) 642-5224

               with a copy to:

               Cravath, Swaine & Moore
               825 Eighth Avenue
               New York, New York  10019
               Attention:  Allen Finkelson, Esq.
               Telecopier No.:  (212) 474-3700

         (b) If to American:

               American Radio Systems Corporation
               116 Huntington Avenue
               Boston, Massachusetts 02116
               Attention: Steven B. Dodge, President and Chief Executive Officer
               Telecopier No.:  (617) 375-7575

                                      -48-


<PAGE>



               with a copy to:
               
               Sullivan & Worcester LLP
               One Post Office Square
               Boston, Massachusetts 02109
               Attention:  Norman A. Bikales, Esq.
               Telecopier No.:  (617) 338-2880

or to such other person(s),  telex or facsimile  number(s) or address(es) as the
party to receive any such communication or notice may have designated by written
notice to the other party.

         9.5  Specific  Performance;  Other  Rights  and  Remedies.  Each  party
recognizes and agrees that in the event the other party should refuse to perform
any of its  obligations  under this  Agreement or any Collateral  Document,  the
remedy at law would be inadequate and agrees that for breach of such provisions,
each party shall,  in addition to such other  remedies as may be available to it
at law or in equity or as  provided  in Article  8, be  entitled  to  injunctive
relief and to enforce its rights by an action for  specific  performance  to the
extent permitted by Applicable Law. Each party hereby waives any requirement for
security  or the  posting  of any bond or other  surety in  connection  with any
temporary or permanent award of injunctive, mandatory or other equitable relief.
Nothing  herein  contained  shall be  construed as  prohibiting  each party from
pursuing any other remedies  available to it under Applicable Law or pursuant to
the provisions of this Agreement for such breach or threatened breach, including
without limitation the recovery of damages,  including, to the extent awarded in
any Legal Action,  punitive,  incidental and  consequential  damages  (including
without  limitation  damages  for  diminution  in value and loss of  anticipated
profits) or any other measure of damages permitted by Applicable Law.

         9.6 Survival of Representations,  Warranties, Covenants and Agreements.
None of the  representations  and warranties in this Agreement shall survive the
Merger, and after  effectiveness of the Merger neither  Mergeparty,  American or
their  respective  officers,  directors or  shareholders  shall have any further
obligation with respect  thereto.  This Section 9.6 shall not limit any covenant
or agreement of the parties which by its terms  contemplates  performance  after
the Effective Time.

         9.7  Severability.  If any term or provision of this Agreement shall be
held or deemed  to be, or shall in fact be,  invalid,  inoperative,  illegal  or
unenforceable  as  applied  to  any  particular  case  in  any  jurisdiction  or
jurisdictions,  or in  all  jurisdictions  or  in  all  cases,  because  of  the
conflicting of any provision with any  constitution or statute or rule of public
policy or for any other reason,  such circumstance  shall not have the effect of
rendering the provision or provisions in question invalid, inoperative,  illegal
or unenforceable in any other  jurisdiction or in any other case or circumstance
or of rendering any other  provision or  provisions  herein  contained  invalid,
inoperative,  illegal or  unenforceable to the extent that such other provisions
are not themselves actually in conflict with such constitution,  statute or rule
of public policy, but this Agreement shall be reformed and construed in any such
jurisdiction or case as if such invalid,  inoperative,  illegal or unenforceable
provision had never been contained herein and such provision reformed so that it
would be valid,  operative and  enforceable to the maximum  extent  permitted in
such jurisdiction or in such case.  Notwithstanding the foregoing,  in the event
of any such  determination,  the parties shall negotiate in good faith to modify
this Agreement so as to effect the original  intent of the parties as closely as
possible to the fullest  extent  permitted by  Applicable  Law in an  acceptable
manner to the end that the Merger is fulfilled  and  consummated  to the maximum
extent possible.

         9.8   Counterparts.   This   Agreement   may  be  executed  in  several
counterparts,  each of  which  shall be  deemed  an  original,  but all of which
together shall constitute one and the same  instrument,  binding upon


                                      -49-


<PAGE>


all of the parties.  In pleading or proving any provision of this Agreement,  it
shall not be necessary to produce more than one of such counterparts.

         9.9 Section Headings.  The headings contained in this Agreement are for
reference  purposes  only  and  shall  not in any  way  affect  the  meaning  or
interpretation of this Agreement.

         9.10  Governing  Law. The validity,  interpretation,  construction  and
performance of this Agreement  shall be governed by, and construed in accordance
with,  the  Applicable  Laws of the United States of America and the laws of the
State of New York  applicable to contracts made and performed in such State and,
in any event,  without giving effect to any choice or conflict of laws provision
or rule that would cause the  application  of domestic  substantive  laws of any
other  jurisdiction,  except to the  extent the  corporate  laws of the State of
Delaware   are   applicable.   Anything  in  this   Agreement  to  the  contrary
notwithstanding,  in the event of any dispute  between the parties which results
in a Legal Action,  the  prevailing  party shall be entitled to receive from the
non-prevailing  party  reimbursement  for  reasonable  legal  fees and  expenses
incurred by such prevailing party in such Legal Action.

         9.11 Further Acts. Each party agrees that at any time, and from time to
time, before and after the consummation of the transactions contemplated by this
Agreement,  it  will do all  such  things  and  execute  and  deliver  all  such
Collateral  Documents  and other  assurances,  as the other party or its counsel
reasonably  deems  necessary  or  desirable  in order to carry out the terms and
conditions of this  Agreement  and the  transactions  contemplated  hereby or to
facilitate  the enjoyment of any of the rights  created  hereby or to be created
hereunder.

         9.12 Entire Agreement;  No Other  Representations  or Agreements.  This
Agreement (together with the Disclosure Schedules and the Exhibits and the other
Collateral  Documents  delivered  or to be  delivered  in  connection  herewith)
constitutes  the entire  agreement  of the parties  with  respect to the subject
matter hereof and  supersedes  all prior  agreements,  arrangements,  covenants,
promises, conditions, undertakings, inducements, representations, warranties and
negotiations,  expressed or implied, oral or written,  between the parties, with
respect to the subject  matter  hereof.  Each of the parties is a  sophisticated
legal  entity  that was  advised by  experienced  counsel  and, to the extent it
deemed necessary,  other advisors in connection with this Agreement. Each of the
parties  hereby  acknowledges  that (a) neither party has relied or will rely in
respect of this  Agreement  or the  transactions  contemplated  hereby  upon any
document or written or oral information previously furnished to or discovered by
it or its representatives, other than this Agreement (including the Exhibits and
the  Disclosure  Schedules  and the other  Collateral  Documents) or such of the
foregoing  as are  delivered  at the  Closing,  (b)  there are no  covenants  or
agreements  by or on  behalf  of either  party  hereto or any of its  respective
Affiliates  or  representatives  other  than those  expressly  set forth in this
Agreement and the Collateral  Documents,  and (c) the parties' respective rights
and  obligations  with  respect to this  Agreement  and the events  giving  rise
thereto  will be  solely  as set  forth  in this  Agreement  and the  Collateral
Documents.  WITHOUT LIMITING THE GENERALITY OF THE FOREGOING,  EACH PARTY HERETO
AGREES THAT,  EXCEPT FOR THE  REPRESENTATIONS  AND WARRANTIES  CONTAINED IN THIS
AGREEMENT,  NEITHER AMERICAN NOR MERGEPARTY MAKES ANY OTHER  REPRESENTATIONS  OR
WARRANTIES,  AND EACH HEREBY DISCLAIMS ANY OTHER  REPRESENTATIONS  OR WARRANTIES
MADE BY ITSELF OR ANY OF ITS OFFICERS,  DIRECTORS,  EMPLOYEES, AGENTS, FINANCIAL
AND LEGAL ADVISORS OR OTHER  REPRESENTATIVES,  WITH RESPECT TO THE EXECUTION AND
DELIVERY  OF  THIS   AGREEMENT   OR  THE   TRANSACTIONS   CONTEMPLATED   HEREBY,
NOTWITHSTANDING  THE  DELIVERY  OR  DISCLOSURE  TO  THE  OTHER  OR  THE  OTHER'S
REPRESENTATIVES  OF ANY  DOCUMENTATION OR OTHER  INFORMATION WITH RESPECT TO ANY
ONE OR MORE OF THE FOREGOING.


                                      -50-


<PAGE>

         9.13  Assignment.  This Agreement  shall not be assignable by any party
and any such  assignment  shall be null and void,  except that it shall inure to
the benefit of and be binding  upon any  successor to each party by operation of
Law,  including by way of merger,  consolidation or sale of all or substantially
all of its assets,  and each party may assign its rights and remedies  hereunder
to any bank or other financial  institution  which has loaned funds or otherwise
extended credit to it.

         9.14  Parties in  Interest.  This  Agreement  shall be binding upon and
inure  solely to the benefit of each party and their  permitted  successors  and
assigns,  and nothing in this Agreement,  express or implied,  is intended to or
shall  confer  upon any  Person  any  right,  benefit  or remedy  of any  nature
whatsoever under or by reason of this Agreement, except as otherwise provided in
Articles 2 and 3 and Sections 6.8(d), 6.12 and 9.13.

         9.15 Mutual Drafting. This Agreement is the result of the joint efforts
of Mergeparty and American,  and each  provision  hereof has been subject to the
mutual consultation, negotiation and agreement of the parties and there shall be
no  construction  against either party based on any  presumption of that party's
involvement in the drafting thereof.

         9.16 Obligations of American and of Mergeparty. Whenever this Agreement
requires a Subsidiary of American to take any action,  such requirement shall be
deemed  to  include  an  undertaking  on the  part of  American  to  cause  such
Subsidiary to take such action. Whenever this Agreement requires a Subsidiary of
Mergeparty to take any action,  such  requirement  shall be deemed to include an
undertaking  on the part of  Mergeparty  to cause such  Subsidiary  to take such
action and, after the Effective  Time, on the part of the Surviving  Corporation
to cause such Subsidiary to take such action.

         9.17  Mergeparty  Agent for  Mergeparty  Subsidiary.  Anything  in this
Agreement to the contrary  notwithstanding,  Mergeparty Subsidiary hereby grants
Mergeparty  an  irrevocably  power of attorney and hereby  irrevocably  appoints
Mergeparty  its agent for all  purposes  of this  Agreement,  including  without
limitation  for the purpose of executing and  delivering  extensions of the time
for the  performance  of any of the  obligations  or other  acts of  Mergeparty,
waivers, terminations or amendments, and any action taken by Mergeparty pursuant
to  such  power  of  attorney  and  agency,  and  any  such  extension,  waiver,
termination or amendment executed and delivered by Mergeparty,  shall be binding
upon  Mergeparty  Subsidiary  whether or not it has  specifically  approved such
action or executed such extension, waiver, termination or amendment.

         9.18  Original  Merger  Agreement.   Notwithstanding  anything  to  the
contrary in Section 9.3 of the Original Merger  Agreement,  this Agreement shall
not amend or restate the Original  Merger  Agreement,  and the  Original  Merger
Agreement  shall  continue  in full force and effect  without any  amendment  or
modification  thereof  pursuant to the provisions of this Agreement,  until such
time as this  Agreement  shall have been  approved  and adopted by the  Required
Vote.


                            [SIGNATURE PAGE FOLLOWS]

                                      -51-


<PAGE>


         IN WITNESS WHEREOF, American, Mergeparty and Mergeparty Subsidiary have
caused this  Amended and Restated  Agreement  and Plan of Merger to be executed,
pursuant to the  authority  and approval of each of their  respective  Boards of
Directors,  as of the date  first  written  above by their  respective  officers
thereunto duly authorized.

                              American Radio Systems Corporation


                              By: /s/ Steven B. Dodge
                                Name: Steven B. Dodge
                                Title:    Chairman of the Board, President and
                                          Chief Executive Officer

                              CBS Corporation



                              By: /s/ Frederic G. Reynolds
                                  Name:
                                  Title:


                              R Acquisition Corp.


                              By: /s/ Frederic G. Reynolds
                                  Name:
                                  Title:


                                      -52-


<PAGE>



                                                                      APPENDIX A

                                   DEFINITIONS


         Accounting Firm shall have the meaning given to it in Section 6.18.

         Adjustment  Amount  shall  have  the  meaning  given  to it in  Section
6.18(d).

         Adverse,  Adversely, when used alone or in conjunction with other terms
(including  without  limitation  "Affect," "Change" and "Effect") shall mean any
Event that has adversely  affected or is reasonably  likely to adversely  affect
(a) the  validity or  enforceability  of this  Agreement  or the  likelihood  of
consummation of the Merger, (b) the business, properties, financial condition or
results of operations of American and its Subsidiaries, taken as a whole, or the
Mergeparty and its  Subsidiaries,  taken as a whole,  as the case may be, or (c)
American's  or  Mergeparty's,  as the  case  may  be,  ability  to  fulfill  its
obligations  under the terms of this Agreement.  Notwithstanding  the foregoing,
and  anything  in this  Agreement  to the  contrary  notwithstanding,  any Event
affecting  the radio  broadcasting  industry or the  national or any regional or
market economy  generally  shall not be deemed to constitute an Adverse  Change,
have an Adverse  Effect or to Adversely  Affect within the meaning of any of the
foregoing clauses (a) through (c).

         Affiliate,  Affiliated shall mean, with respect to any Person,  (a) any
other Person at the time  directly or indirectly  controlling,  controlled by or
under direct or indirect  common  control with such Person,  any other Person of
which such  Person at the time owns,  or has the right to  acquire,  directly or
indirectly,  twenty  percent  (20%) or more of any class of the capital stock or
beneficial  interest,  (c) any other Person  which at the time owns,  or has the
right to acquire,  directly or  indirectly,  twenty percent (20%) or more of any
class of the  capital  stock or  beneficial  interest  of such  Person,  (d) any
executive  officer  or  director  of  such  Person,  (e)  with  respect  to  any
partnership,  joint venture or similar Entity, any general partner thereof,  and
(f) when used with respect to an  individual,  shall  include any member of such
individual's immediate family or a family trust.

         Affiliate Agreement shall have the meaning given to it in Section 6.20.

         Agreement  shall have the  meaning  given to it in the third  "Whereas"
paragraph and shall include any amendments executed and delivered by the parties
pursuant to the provisions of Section 9.1.

         American shall have the meaning given to it in the Preamble.

         American  Brokered  Stations  shall mean the radio  broadcast  stations
which  American  has the  right  to  acquire,  but  which  as of the date of the
Original  Merger  Agreement it is operating  pursuant to time  brokerage,  local
marketing or other similar agreements.

         American  Class A Common shall have the meaning  given to it in Section
3.1(d).

         American  Class B Common shall have the meaning  given to it in Section
3.1(d).

         American  Class C Common shall have the meaning  given to it in Section
3.1(d).

         American  Common  Stock shall have the  meaning  given to it in Section
3.1(d).

         American  Conversion  Fraction  shall have the  meaning  given to it in
Section 3.5.

                                       A-1


<PAGE>



         American Convertible Preferred Stock shall have the meaning given to it
in Section 2.5.

         American Cumulative  Preferred Stock shall have the meaning given to it
in Section 2.5.

         American   Disclosure  Schedule  shall  mean  the  American  Disclosure
Schedule  dated as of the date of the  Original  Merger  Agreement  delivered by
American to  Mergeparty  simultaneously  with the  execution and delivery of the
Original Merger Agreement.

         American FCC Licenses means all FCC Licenses  issued to American or any
of its  Subsidiaries  and  used  in the  business  or  operations  of any of the
American  Stations,  including  those  listed on Section  4.6(a) of the American
Disclosure  Schedule  (other  than  those  relating  to  the  American  Brokered
Stations,  which shall be deemed American FCC Licenses only upon consummation of
the acquisition of the applicable American Brokered Station),  and any additions
thereto between the date of the Original Merger  Agreement and the Closing Date.
Auxiliary  broadcast  licenses issued pursuant to 47 C.F.R. Part 74 shall not be
deemed to be material American FCC Licenses.

         American  Financial  Statements  shall have the meaning  given to it in
Section 4.2.

         American Options shall have the meaning given to it in Section 6.8.

         American  Preferred Stock shall have the meaning given to it in Section
2.5.

         American SEC  Documents  shall have the meaning  given to it in Section
4.2.

         American  September  10-Q shall have the meaning given to it in Section
4.2.

         American Stations means the radio broadcast stations owned by American,
or which it has the right to acquire (and acquires prior to the Closing Date but
only from and after  such  acquisition)  as of the date of the  Original  Merger
Agreement;  provided,  however,  that  American  Stations  shall not include any
American Station disposed of by American  subsequent to the date of the Original
Merger Agreement not in violation of the provisions of this Agreement;  further,
provided, that American Stations shall include American Brokered Stations if the
context so requires.

         American  Stock  means  the  American  Common  Stock  and the  American
Preferred stock.

         American  Stockholders  Meeting  shall have the meaning  given to it in
Section 6.5.

         American  Stockholders Tower Meeting shall have the meaning given to it
in Section 6.5.

         American 10-K shall have the meaning given to it in Section 4.2.

         American Tax Group shall mean American and those of its Subsidiaries as
are included in the consolidated Federal Income Tax Returns of American.

         American Tower shall have the meaning given to it in Section 3.1(d).

         American  Tower  Group  shall have the  meaning  given to it in Section
6.17.


                                       A-2


<PAGE>


         American's   knowledge   (including  the  term  "to  the  knowledge  of
American")  means the actual  knowledge  of the Chief  Executive  Officer or the
Chief Financial Officer of American,  and that such Officer shall have reason to
believe and shall  believe that the subject  representation  or warranty is true
and accurate as stated.

         Antitrust  Division  shall  have the  meaning  given  to it in  Section
6.2(c).

         Applicable Law shall mean,  with respect to any Person,  any Law of any
Authority,  whether  domestic or foreign,  to which such Person is subject or by
which it or any of its business or  operations is subject or any of its property
or assets is bound.

         Applications shall have the meaning given to it in Section 6.2(b).

         Appraised  Total Value  shall have the  meaning  given to it in Section
3.4(c).

         Arbitrator shall have the meaning given to it in Section 3.4(c).

         ATC  Merger  Agreement  shall have the  meaning  given to it in Section
4.1(e).

         ATS Mergercorp shall have the meaning given to it in Section 3.5.

         ATS  Mergercorp  Common  Stock  shall have the  meaning  given to it in
Section 4.1(e).

         Authority shall mean any governmental or quasi-governmental  authority,
whether  administrative,  executive,  judicial,  legislative  or  other,  or any
combination   thereof,   including  without   limitation  any  federal,   state,
territorial,   county,   municipal  or  other   government  or  governmental  or
quasi-governmental agency, arbitrator,  authority,  board, body, branch, bureau,
central bank or comparable  agency or Entity,  commission,  corporation,  court,
department,  instrumentality,  master, mediator, panel, referee, system or other
political unit or  subdivision or other Entity of any of the foregoing,  whether
domestic or foreign.

         Benefit Arrangement shall mean, with respect to any Person, any benefit
arrangement  that is not a Plan,  including  (a) any  employment,  severance  or
consulting  agreement,  (b) any arrangement  providing for insurance coverage or
workers'  compensation  benefits,  (c) any  incentive  bonus or  deferred  bonus
arrangement,  (d) any arrangement providing termination allowance,  severance or
similar  benefits,  (e) any  equity  compensation  plan,  and  (f) any  deferred
compensation plan which American or any ERISA Affiliate  maintains,  contributes
to or is  required  to  contribute  to for the  benefit of any current or former
officers, employees, agents, directors or independent contractors of American or
any of its ERISA Affiliates.

         Cash  Consideration  shall  have the  meaning  given  to it in  Section
3.1(d).

         Certificate  of Merger  shall have the  meaning  given to it in Section
2.3.

         Certificates shall have the meaning given to it in Section 3.2(b).

         CD Amount shall have the meaning given to it in Section 6.18(c).

         Claims shall mean any and all debts, liabilities,  obligations, losses,
damages,  deficiencies,  assessments  and  penalties,  together  with all  Legal
Actions, pending or threatened, claims and judgments of whatever kind 

                                       A-3


<PAGE>

and nature relating  thereto,  and all fees,  costs,  expenses and disbursements
(including without limitation  reasonable attorneys' and other legal fees, costs
and expenses) relating to any of the foregoing.

         Closing shall have the meaning given to it in Section 2.2.

         Closing  Balance  Sheet shall have the  meaning  given to it in Section
6.18.

         Closing Date shall have the meaning given to it in Section 2.2.

         Closing Net Debt shall have the meaning given to it in Section 6.18.

         Closing Statement shall have the meaning given to it in Section 6.18.

         Closing  Working  Capital shall have the meaning given to it in Section
6.18.

         COBRA shall mean the Consolidated Omnibus Budget  Reconciliation Act of
1985,  as  amended,  as set  forth  in  Section  4980B of the Code and Part 6 of
Subtitle B of Title I of ERISA.

         Code shall mean the Internal  Revenue  Code of 1986,  and the rules and
regulations  thereunder,  all as from time to time in effect,  or any  successor
law,  rules or  regulations,  and any  reference to any  statutory or regulatory
provision  shall be deemed  to be a  reference  to any  successor  statutory  or
regulatory provision.

         Collateral  Document shall mean any agreement,  certificate,  contract,
instrument,  notice,  opinion  or  other  document  delivered  pursuant  to  the
provisions of this Agreement,  including without limitation, the Confidentiality
Agreement, the Tower Documentation and the Tower Merger Agreement.

         Commission or SEC shall mean the Securities and Exchange Commission and
shall include any successor Authority.

         Contracts shall have the meaning given to it in Section 4.19(a).

         Confidentiality Agreement shall mean the letter agreement, dated August
21, 1997 between American and Mergeparty.

         Control (including the terms  "controlled,"  "controlled by" and "under
common control with") means the possession, directly or indirectly or as trustee
or executor,  of the power to direct or cause the direction of the management or
policies of a Person,  or the disposition of such Person's assets or properties,
whether through the ownership of stock, equity or other ownership,  by contract,
arrangement or understanding,  or as trustee or executor,  by contract or credit
arrangement or otherwise.

         Convertible Securities shall mean any evidences of indebtedness, shares
of capital  stock  (other than  common  stock) or other  securities  directly or
indirectly convertible into or exchangeable for shares of capital stock, whether
or not the right to convert or exchange thereunder is immediately exercisable or
is conditioned  upon the passage of time, the  occurrence or  non-occurrence  or
existence or non-existence of some other Event, or both.

         Court shall have the meaning given to it in Section 3.4(c).

         CSFB shall have the meaning given to it in Section 4.14.

                                       A-4


<PAGE>

         Current Assets shall have the meaning given to it in Section 6.18(b).

         DCL shall have the meaning given to it in Section 2.1.

         Debt Amount shall have the meaning given to it in Section 6.18(c).

         Determination  Deadline  shall have the meaning  given to it in Section
3.4(c).

         Disclosure Schedule shall mean the Mergeparty  Disclosure Schedule,  if
any, or the American Disclosure Schedule, as the case may be.

         Dissenting Shares shall have the meaning given to it in Section 3.4(a).

         Divestiture  Condition  means any condition  imposed or required by the
FCC  (including  conditions  required by the FCC's multiple  ownership  rules or
policies), the Antitrust Division or the FTC as a condition to its consent to or
approval  of the  transfer  of control of any of the  American  FCC  Licenses or
otherwise to the transactions  (or any of them)  contemplated by this Agreement,
including without  limitation the Merger, or as a condition to its agreement not
to  institute  any Legal Action to prevent the transfer of control of any of the
American  FCC  Licenses  or  otherwise  to  prevent  any  of  the   transactions
contemplated  hereby,  which would require Mergeparty or any of its Subsidiaries
or any of its  other  Affiliates  to  dispose  of one or  more  of the  American
Stations or American Brokered Stations, or in Mergeparty's sole discretion,  one
or more of the radio broadcast stations owned by Mergeparty and operating in the
same Arbitron Survey area as any of the American  Stations or American  Brokered
Stations;  provided, however, that with respect to compliance with any condition
imposed by the FCC,  Mergeparty shall have been afforded a period of six months,
from  Closing,  through the use of trusts or  otherwise,  within which to comply
with the radio duopoly overlap rule, 47 C.F.R.  ss.  73.3555(a),  and Mergeparty
shall  have been  afforded  temporary,  rather  than  permanent,  waivers of the
one-to-a-market  rule,  47  C.F.R.  ss.  73.3555(c),  so long as such  temporary
waivers  shall remain in effect until at least 6 months  following the effective
date of FCC action  concluding the ongoing  proceeding in MM Docket Nos. 91-221,
87-8 (FCC 94-322) or a successor  rulemaking  proceeding  pending at the time of
the grant of the FCC Order, that considers the one-to-a-market rule.

         D&O Insurance shall have the meaning given to it in Section 6.12(c).

         Effective Time shall have the meaning given to it in Section 2.3.

         Entity shall mean any corporation,  firm, unincorporated  organization,
association,  partnership,  limited  liability  company,  trust  (inter vivos or
testamentary),  estate of a deceased, insane or incompetent individual, business
trust,  joint stock  company,  joint  venture or other  organization,  entity or
business,  whether acting in an individual,  fiduciary or other capacity, or any
Authority.

         Environmental  Law  excluding any  regulations  issued by the FCC shall
mean any Law relating to or otherwise imposing liability or standards of conduct
concerning  pollution  or  protection  of  the  environment,  including  without
limitation,  Laws  relating to  emissions,  discharges,  releases or  threatened
releases  of  Hazardous  Materials  into  the  environment  (including,  without
limitation,  ambient air, surface water,  ground water, mining or reclamation of
mined land,  land surface or subsurface  strata) or otherwise that relate to the
manufacture,  processing,  generation,  distribution,  use, treatment,  storage,
disposal, cleanup, transport or handling of pollutants,  contaminants, chemicals
or industrial, toxic or hazardous substances, materials or wastes. Environmental
Laws shall include without limitation the Comprehensive  Environmental Response,
Compensation  and Liability Act (42 U.S.C.  Section 6901 et seq.), the Hazardous
Material  Transportation  Act (49 U.S.C.  Section  1801 et seq.),  the  Resource
Conservation  and  Recovery Act (42 U.S.C.  Section  6901 et

                                       A-5


<PAGE>


seq.), the Federal Water Pollution Control Act (33 U.S.C. Section 1251 et seq.),
the Clean Air Act (42 U.S.C. Section 7401 et seq.), the Toxic Substances Control
Act (15 U.S.C. Section 2601 et seq.), the Occupational Safety and Health Act (29
U.S.C. Section 651 et seq.), the Federal Insecticide,  Fungicide and Rodenticide
Act (7  U.S.C.  Section  136 et  seq.),  and  the  Surface  Mining  Control  and
Reclamation  Act of 1977 (30 U.S.C.  Section  1201 et seq.),  and any  analogous
federal, state, local or foreign Laws, and the rules and regulations promulgated
thereunder,  all as from time to time in effect,  and any  reference to any such
statutory  or  regulatory  provision  shall be deemed to be a  reference  to any
successor statutory or regulatory provision.

         Environmental  Permit  shall  mean,  with  respect to any  Person,  any
Governmental Authorization required by or pursuant to any Environmental Law.

         ERISA shall mean the Employee  Retirement  Income Security Act of 1974,
and the rules and regulations thereunder, all as from time to time in effect, or
any successor law, rules or regulations, and any reference to any such statutory
or  regulatory  provision  shall be deemed to be a  reference  to any  successor
statutory or regulatory provision.

         ERISA  Affiliate  shall  mean any  Person  that is  treated as a single
employer with American  under  Sections  414(b),  (c), (m) or (o) of the Code or
Section 4001(b)(1) of ERISA.

         ESOP shall have the meaning given to it in Section 4.9(a)(xvi).

         Event  shall  mean the  existence  or  occurrence  of any act,  action,
activity,  circumstance,  condition,  event,  fact,  failure  to act,  omission,
incident or practice, or any set or combination of any of the foregoing.

         Exchange Act shall mean the  Securities  Exchange Act of 1934,  and the
rules and  regulations  thereunder,  all as from time to time in effect,  or any
successor law, rules or regulations,  and any reference to any such statutory or
regulatory  provision  shall  be  deemed  to be a  reference  to  any  successor
statutory or regulatory provision.

         Exchange Agent shall have the meaning given to it in Section 3.2(a).

         Expenses shall have the meaning given to it in Section 9.3.

         Extended  Tower  Lease  shall have the  meaning  given to it in Section
6.19(b).

         FCA  shall  mean the  Communication  Act of  1934,  and the  rules  and
regulations  thereunder,  all as from time to time in effect,  or any  successor
law, rules or regulations, and any reference to any such statutory or regulatory
provision  shall be deemed  to be a  reference  to any  successor  statutory  or
regulatory provision.

         FCC shall mean the Federal Communications  Commission and shall include
any successor Authority.

         FCC Consents means actions by the FCC (including the Chief,  Mass Media
Bureau,  acting under delegated  authority) granting its consent to the transfer
of control of the American  FCC  Licenses  for each of the American  Stations to
Mergeparty as  contemplated  by this  Agreement  whether or not such consent has
become a Final Order.

         FCC   Licenses   means  all  of  the   licenses,   permits   and  other
authorizations  issued by the FCC to an owner and  operator  of radio  broadcast
stations.


                                       A-6


<PAGE>

         FCC Order shall have the meaning given to it in Section 7.1(b).

         Filed  American  SEC  Documents  shall have the meaning  given to it in
Section 4.2.

         Final  Adjustment  Amount shall have the meaning given to it in Section
6.18(d).

         Final  Order  shall  mean,  with  respect to any  Authority,  including
without  limitation  the FCC, a consent  or  approval  with  respect to which no
appeal,  no stay, no petition or  application  for  rehearing,  reconsideration,
review or stay, whether on motion of the applicable Authority or other Person or
otherwise,  and no other Legal Action contesting such consent or approval, is in
effect or  pending  and as to which the time or  deadline  for  filing  any such
appeal,  petition or application or other Legal Action has expired or, if filed,
has  been  denied,  dismissed  or  withdrawn,  and  the  time  or  deadline  for
instituting any further Legal Action has expired.

         FTC shall have the meaning given to it in Section 6.2(c).

         GAAP shall mean generally accepted  accounting  principles as in effect
from time to time in the United States of America.

         Governmental  Authorizations  shall  mean all  approvals,  concessions,
consents,   franchises,   licenses,  permits,  plans,  registrations  and  other
authorizations  of all  Authorities,  including the FCC Licenses,  issued by the
FCC, the Federal Aviation  Administration  and any other Authority in connection
with the conduct of business or operations of any of the Stations.

         Governmental  Filings shall mean all filings,  including  franchise and
similar Tax  filings,  and the payment of all fees,  assessments,  interest  and
penalties associated with such filings, with all Authorities.

         Hart-Scott-Rodino  Act  shall  mean  the  Hart-Scott-Rodino   Antitrust
Improvements Act of 1976, and the rules and regulations thereunder,  all as from
time to time in effect,  or any successor  law,  rules or  regulations,  and any
reference to any such statutory or regulatory  provision shall be deemed to be a
reference to any successor statutory or regulatory provision.

         Hazardous  Materials  shall mean and include any  substance,  material,
waste, constituent, compound, chemical, natural or man-made element or force (in
whatever state of matter):  (a) the presence of which requires  investigation or
remediation under any Environmental  Law; or (b) that is defined as a "hazardous
waste" or  "hazardous  substance"  under any  Environmental  Law; or (c) that is
toxic, explosive,  corrosive,  etiologic,  flammable,  infectious,  radioactive,
carcinogenic,   mutagenic  or  otherwise  hazardous  and  is  regulated  by  any
applicable  Authority or subject to any Environmental  Law; or (d) that poses or
threatens  to pose a hazard to the  health or  safety  of  persons;  or (e) that
contains  gasoline,  diesel  fuel  or  other  petroleum  hydrocarbons,   or  any
by-products  or  fractions  thereof,  natural  gas,  polychlorinated   biphenyls
("PCBs") and  PCB-containing  equipment,  radon or other  radioactive  elements,
ionizing radiation,  lead, asbestos or asbestos- containing  materials,  or urea
formaldehyde foam insulation.

         indebtedness   shall  mean,   with  respect  to  any  Person,   without
duplication,  (A) all  obligations  of such Person for borrowed  money,  or with
respect to deposits or advances of any kind to such Person,  (B) all obligations
of such Person evidenced by bonds, debentures, notes or similar instruments, (C)
all obligations of such Person under  conditional  sale or other title retention
agreements relating to property purchased by such Person, (D) all obligations of
such  Person  issued or assumed as the  deferred  purchase  price of property or
services  (excluding  obligations of such Person to creditors for raw materials,
inventory,  services  and  supplies  


                                       A-7


<PAGE>

incurred in the ordinary course of such Person's business),  (E) all capitalized
lease  obligations of such Person,  (F) all obligations of others secured by any
Lien on property or assets owned or acquired by such Person,  whether or not the
obligations  secured  thereby have been  assumed,  (G) all  obligations  of such
Person  under  interest  rate or currency  hedging  transactions  (valued at the
termination value thereof),  (H) all letters of credit issued for the account of
such Person and (I) all guarantees and  arrangements  having the economic effect
of a guarantee of such Person or any indebtedness of any other Person.

         Indemnified  Parties  shall  have the  meaning  given to it in  Section
6.12(b).

         Law shall mean any (a) administrative,  judicial,  legislative or other
action,  code,  consent  decree,  constitution,  decree,  directive,  enactment,
finding, guideline, law, injunction, interpretation, judgment, order, ordinance,
proclamation,  promulgation, regulation, requirement, rule, rule of law, rule of
public policy, settlement agreement, statute, or writ of any Authority, domestic
or foreign; (b) the common law, or other legal or quasi-legal precedent;  or (c)
arbitrator's,    mediator's   or   referee's   award,   decision,   finding   or
recommendation.

         Legal  Action  shall  mean,  with  respect to any  Person,  any and all
litigation or legal or other  actions,  arbitrations,  counterclaims,  hearings,
investigations,  proceedings  or  suits,  at law or in  arbitration,  equity  or
admiralty,  whether or not purported to be brought on behalf of such Person,  by
or before any  Authority,  against such Person or involving any of such Person's
business or assets.

         Liabilities shall have the meaning given to it in Section 6.18(b).

         Lien shall mean any of the  following:  mortgage;  lien  (statutory  or
other) or other  security  agreement,  arrangement  or interest;  hypothecation,
pledge  or  other  deposit  arrangement;  assignment;  charge;  levy;  executory
seizure;   attachment;   garnishment;   encumbrance   (including  any  easement,
exception,  reservation or limitation,  right of way, and the like); conditional
sale,  title  retention  or other  similar  agreement,  arrangement,  device  or
restriction;  any  financing  lease  involving  substantially  the same economic
effect as any of the foregoing;  the filing of any financing statement under the
Uniform Commercial Code or comparable law of any jurisdiction; or restriction on
sale, transfer, assignment, disposition or other alienation.

         Material, Materially or materiality for the purposes of this Agreement,
shall, unless specifically stated to the contrary,  be determined without regard
to the fact that various  provisions of this Agreement set forth specific dollar
amounts.

         Material  Agreement  shall  mean,  with  respect  to  any  Person,  any
agreement, arrangement, contract, undertaking, understanding or other obligation
or liability  which (a) was not entered into in the ordinary course of business,
it being understood and agreed by the parties that the acquisition,  disposition
or exchange of radio  stations is in the ordinary  course of  business,  (b) was
entered into in the ordinary course of business which (i) involved the purchase,
sale or lease of goods or materials,  or purchase of services,  aggregating more
than $10,000,000 during any of the last three fiscal years of such Person,  (ii)
extends  for more  than six (6)  months  from  the date of the  Original  Merger
Agreement, or (iii) is not terminable on thirty (30) days or less notice without
material penalty or other payment,  (c) involves  indebtedness  aggregating more
than  $10,000,000,  (d) is or otherwise  constitutes a written  agency,  broker,
dealer,  license,  distributorship,  sales  representative  or  similar  written
agreement,  or (e)  accounted for more than ten percent (10%) of the revenues of
Mergeparty or American Stations,  as the case may be, in the last fiscal year of
such Person or is likely to account for more than ten percent  (10%) of revenues
of Mergeparty or American, as the case may be, during the current fiscal year of
such Person.


                                       A-8


<PAGE>


         Maximum Premium shall have the meaning given to it in Section 6.12(c).

         Merger  Consideration  shall  have the  meaning  given to it in Section
3.1(d).

         Mergeparty shall have the meaning given to it in the Preamble.

         Mergeparty  Brokered  Stations shall mean the radio broadcast  stations
which  Mergeparty  has the  right  to  acquire  but  which as of the date of the
Original  Merger  Agreement it is operating  pursuant to time  brokerage,  local
marketing or other similar agreements.

         Mergeparty  Disclosure  Schedule shall mean the  Mergeparty  Disclosure
Schedule  dated as of the date of the  Original  Merger  Agreement  delivered by
Mergeparty  to American  simultaneously  with the  execution and delivery of the
Original Merger Agreement.

         Mergeparty  Stations  means  the  radio  broadcast  stations  owned  by
Mergeparty,  or which it has the right to  acquire  (and  acquires  prior to the
Closing  Date but only from and after  such  acquisition)  as of the date of the
Original Merger Agreement; provided, however, that Mergeparty Stations shall not
include any Mergeparty Station disposed of by Mergeparty  subsequent to the date
of the Original  Merger  Agreement  not in violation of the  provisions  of this
Agreement;  provided further,  however,  that the term Mergeparty Stations shall
include Mergeparty Brokered Stations if the context so requires.

         Mergeparty  Subsidiary  shall  have  the  meaning  given  to it in  the
Preamble.

         Mergeparty's  knowledge  (including  the  term  "to  the  knowledge  of
Mergeparty")  means the actual  knowledge of the Chief Executive  Officer or the
Chief Financial  Officer of Mergeparty,  and that such Officer shall have reason
to believe and shall believe that the subject representation or warranty is true
and accurate as stated.

         Merger  shall  have  the  meaning  given to it in the  third  "Whereas"
paragraph.

         Merger  Consideration  shall  have the  meaning  given to it in Section
3.1(d).

         Multiemployer  Plan shall mean a Plan which is a  "multiemployer  plan"
within the meaning of Section 4001(a)(3) of ERISA.

         Net Debt shall have the meaning given to it in Section 6.18(c).

         Notice of  Disagreement  shall have the meaning  given to it in Section
6.18.

         NYSE shall mean the New York Stock Exchange.

         Option  Securities shall mean all rights,  options,  calls,  contracts,
agreements, warrants, understandings, restrictions, arrangements or commitments,
including without limitation,  any rights plan or other anti-takeover  agreement
or  arrangement,  evidencing the right to subscribe  for,  purchase or otherwise
acquire,  or otherwise  providing  for the issuance of shares of capital  stock,
voting  securities  or  Convertible  Securities,  whether  or not the  right  to
subscribe for,  purchase or otherwise  acquire,  or otherwise  providing for the
issuance, is immediately exercisable or is conditioned upon the passage of time,
the occurrence or non-occurrence or the existence or non-existence of some other
Event.


                                       A-9


<PAGE>


         Optionholder shall have the meaning given to it in Section 6.8(a).

         Organic  Document  shall  mean,  with  respect  to a Person  which is a
corporation,  its charter,  its by-laws and all stockholder  agreements,  voting
trusts and similar arrangements applicable to any of its capital stock and, with
respect to a Person which is a  partnership,  its agreement and  certificate  of
partnership,  any  agreements  among  partners,  and any  management and similar
agreements  between the partnership  and any general  partners (or any Affiliate
thereof).

         Original  Merger  Agreement  shall have the meaning  given to it in the
first "Whereas" paragraph.

         Permitted  Liens shall mean (a) Liens for current Taxes not yet due and
payable,  and (b) such  imperfections  of  title,  easements,  encumbrances  and
mortgages or other Liens, if any, as are not,  individually or in the aggregate,
substantial in character,  amount or extent and do not  materially  detract from
the value, or materially interfere with the present use, of the property subject
thereto or affected  thereby,  or  otherwise  materially  impair the business or
operations of the American Stations or the Mergeparty Stations,  as the case may
be.

         Person shall mean any natural individual or any Entity.

         Plan shall mean,  with respect to any Person and at a particular  time,
any employee benefit plan which is covered by ERISA and in respect of which such
Person or an ERISA  Affiliate is (or, if such plan were terminated at such time,
would under  Section 4069 of ERISA be deemed to be) an  "employer" as defined in
Section  3(5)  of  ERISA,  which  American  or any  ERISA  Affiliate  maintains,
contributes to or is required to contribute to for the benefit of any current or
former  officers,  employees,  agents,  directors or independent  contractors of
American or any of its ERISA Affiliates.

         Post-Closing  American  Group  shall  have the  meaning  given to it in
Section 6.18

         Private Authorizations shall mean all approvals, concessions, consents,
franchises,  licenses,  permits,  and other authorizations of all Persons (other
than Authorities) including without limitation those with respect to copyrights,
computer software programs,  patents,  service marks,  trademarks,  trade names,
technology and know-how.

         Prohibited  Transaction  shall have the meaning  given to it in Section
6.2(a).

         Proxy Statement shall have the meaning given to it in Section 6.6(a).

         Registration  Statement  shall have the meaning  given to it in Section
6.6(b).

         Regulations  shall mean the federal income tax regulations  promulgated
under  the Code,  as such  Regulations  may be  amended  from time to time.  All
references  herein to specific  sections of the Regulations shall be deemed also
to refer to any  corresponding  provisions  of succeeding  Regulations,  and all
references  to  temporary  Regulations  shall  be  deemed  also to  refer to any
corresponding provisions of final Regulations.

         Representatives shall have the meaning given to it in Section 6.1.

         Required    Divestitures   means   all   divestitures,    terminations,
arrangements  and  restructurings  identified in Section 5.2c) of the Mergeparty
Disclosure  Schedule,   if  any,  and  all  other  divestitures,   terminations,
arrangements or  restructurings,  if any, arising after the date of the Original
Merger  Agreement that would have

                                      A-10


<PAGE>

 been required to be listed on Section 5.2c) of
the Mergeparty  Disclosure  Schedule if known to be in existence as of such date
or that are necessary to satisfy any and all Divestiture Conditions.

         Required Tower Vote shall have the meaning given to it in Section 4.13.

         Required Vote shall have the meaning given to it in Section 4.13.

         Required    Divestitures   means   all   divestitures,    terminations,
arrangements  and  restructurings  identified in Section 5.2c) of the Mergeparty
Disclosure  Schedule,   if  any,  and  all  other  divestitures,   terminations,
arrangements or  restructurings,  if any, arising after the date of the Original
Merger  Agreement that would have been required to be listed on Section 5.2c) of
the Mergeparty  Disclosure  Schedule if known to be in existence as of such date
or that are necessary to satisfy any and all Divestiture Conditions.

         Restated  Certificate  shall  have the  meaning  given to it in Section
4.11.

         ss.162(m) Options shall have the meaning given to it in Section 6.8(e).

         Securities Act shall mean the Securities Act of 1933, and the rules and
regulations of the Commission thereunder, all as from time to time in effect, or
any successor law, rules or regulations, and any reference to any such statutory
or  regulatory  provision  shall be deemed to be a  reference  to any  successor
statutory or regulatory provision.

         Stations  shall  mean,  collectively,  the  American  Stations  and the
Mergeparty Stations.

         Subsidiary shall mean, with respect to a Person,  any Entity a majority
of the capital stock  ordinarily  entitled to vote for the election of directors
of which,  or if no such voting stock is  outstanding,  a majority of the equity
interests of which, is owned directly or indirectly, legally or beneficially, by
such Person or any other Person controlled by such Person.

         Surviving  Corporation  shall have the  meaning  given to it in Section
2.1.

         Tax (and "Taxable,"  which shall mean subject to Tax), shall mean, with
respect to any Person,  (a) all taxes (domestic or foreign),  including  without
limitation any income (net, gross or other, including recapture of any tax items
such as  investment  tax  credits),  alternative  or add-on  minimum tax,  gross
income,  gross receipts,  gains,  sales, use, leasing,  lease, user, ad valorem,
transfer, recording, franchise, profits, property (real or personal, tangible or
intangible),  fuel,  license,  withholding on amounts paid to or by such Person,
payroll,  employment,  unemployment,  social security, excise, severance, stamp,
occupation, premium, environmental or windfall profit tax, custom, duty or other
tax, or other like  assessment or charge of any kind  whatsoever,  together with
any  interest,  levies,  assessments,  charges,  penalties,  additions to tax or
additional  amounts  imposed by any Taxing  Authority,  (b) any joint or several
liability of such Person with any other Person for the payment of any amounts of
the type  described  in (a) of this  definition,  and (c) any  liability of such
Person for the payment of any amounts of the type  described  in (a) as a result
of any express or implied obligation to indemnify any other Person.

         Tax Claim shall mean any Claim which relates to Taxes.

         Tax Return or Returns shall mean all returns, consolidated or otherwise
(including without limitation  information  returns),  required to be filed with
any Authority with respect to Taxes.

 
                                      A-11


<PAGE>

        Taxing   Authority  shall  mean  any  Authority   responsible  for  the
imposition of any Tax.

         Termination Date shall have the meaning given to it in Section 8.1.

         Tower  Business  shall  mean  the  business   conducted  by  the  Tower
Subsidiaries.

         Tower  Common  Stock,  Tower  Class A Common,  Tower Class B Common and
Tower  Class C Common  shall  have the  meaning  given to such  terms in Section
3.1(d).

         Tower  Deconsolidation  shall have the  meaning  given to it in Section
6.17.

         Tower  Deconsolidation  Date  shall  have  the  meaning  given to it in
Section 6.17.

         Tower Documentation shall have the meaning given to it in Section 6.17.

         Tower Employees shall have the meaning given to it in Section 6.17.

         Tower Leases shall have the meaning given to it in Section 6.19.

         Tower Merger shall have the meaning given to it in Section 3.5.

         Tower Merger  Agreement  shall have the meaning  given to it in Section
3.5.

         Tower  Merger  Consideration  shall  have  the  meaning  given to it in
Section 3.5.

         Tower  Merger  Effective  Time  shall have the  meaning  given to it in
Section 3.5.

         Tower Merger Tower  Consideration shall have the meaning given to it in
Section 3.5.

         Tower Proxy  Statement  shall have the  meaning  given to it in Section
6.6(a).

         Tower Separation shall have the meaning given to it in Section 6.17.

         Tower Stock Consideration shall have the meaning given to it in Section
3.1(d).

         Tower  Stock  Payment  shall  have the  meaning  given to it in Section
3.4(c).

         Towers shall have the meaning given to it in Section 6.19.

         Tower Subsidiaries shall mean American Tower and its Subsidiaries.

         Uncontrollable  Events  shall have the  meaning  given to it in Section
6.2(d).

         WC Amount shall have the meaning given to it in Section 6.18(b).

         Working Capital shall have the meaning given to it in Section 6.18(b).

                                      A-12
<PAGE>
                                                                       EXHIBIT D

                          AGREEMENT AND PLAN OF MERGER

                                 By and Between

                       AMERICAN RADIO SYSTEMS CORPORATION

                                       and

                             ATS MERGER CORPORATION

                                   Dated as of

                                December 18, 1997











<PAGE>
<TABLE>
<CAPTION>


                                TABLE OF CONTENTS
<S>              <C>                                                                                             <C>
ARTICLE 1         DEFINED TERMS...................................................................................1

ARTICLE 2         THE TOWER MERGER................................................................................2
                  2.1      The Tower Merger.......................................................................2
                  2.2      Closing................................................................................2
                  2.3      Effective Time.........................................................................2
                  2.4      Effect of the Merger...................................................................2
                  2.5      Certificate of Designation.............................................................2
                  2.6      Bylaws.................................................................................2
                  2.7      Directors and Officers.................................................................2

ARTICLE 3         CONVERSION OF SHARES; EXCHANGE OF CERTIFICATES..................................................3
                  3.1      Conversion of Capital Stock............................................................3
                  3.2      Exchange of Certificates.  ............................................................4

ARTICLE 4         REPRESENTATIONS AND WARRANTIES OF ATS MERGERCORP................................................6

ARTICLE 5         REPRESENTATIONS AND WARRANTIES OF ARS...........................................................8

ARTICLE 6         CLOSING CONDITIONS..............................................................................9
                  6.1      Conditions to Obligations of Each Party to Effect the Merger...........................9
                  6.2      Conditions to Obligations of ATS Mergercorp............................................9
                  6.3      Conditions to Obligations of ARS......................................................10

ARTICLE 7         TERMINATION, AMENDMENT AND WAIVER..............................................................10
                  7.1      Termination...........................................................................10
                  7.2      Effect of Termination.    ............................................................10

ARTICLE 8         GENERAL PROVISIONS.............................................................................11
                  8.1      Amendment.............................................................................11
                  8.2      Waiver................................................................................11
                  8.3      Fees, Expenses and Other Payments.....................................................11
                  8.4      Notices...............................................................................11
                  8.5      Specific Performance; Other Rights and Remedies.......................................12
                  8.6      Survival of Representations, Warranties, Covenants and Agreements.....................12
                  8.7      Severability..........................................................................12
                  8.8      Counterparts..........................................................................13
                  8.9      Section Headings......................................................................13
                  8.10     Governing Law.........................................................................13
                  8.11     Further Acts..........................................................................13
                  8.12     Entire Agreement; No Other Representations or Agreements..............................13
                  8.13     Assignment............................................................................14
                  8.14     Parties in Interest...................................................................14



APPENDIX A:                Definitions

</TABLE>
                                      

<PAGE>


                          AGREEMENT AND PLAN OF MERGER


         This  Agreement  and Plan of Merger,  dated as of December 18, 1997, by
and between ATS Merger Corporation.,  a Delaware corporation ("ATS Mergercorp"),
and American Radio Systems Corporation, a Delaware corporation ("ARS").

                              W I T N E S S E T H:

         WHEREAS,   ARS,  CBS  Corporation   (formerly,   Westinghouse  Electric
Corporation),  a  Pennsylvania  corporation  ("CBS") and R Acquisition  Corp., a
Delaware corporation ("CBS Sub") are parties to an Agreement and Plan of Merger,
dated as of September 19, 1997 (the "Original Merger Agreement"); and

         WHEREAS,  ARS, CBS and CBS Sub have  simultaneously  with the execution
and delivery of this Agreement  entered into the Amended and Restated  Agreement
and Plan of Merger (the "Restated Merger Agreement") providing for the merger of
CBS Sub with and into ARS on the terms and  conditions  set forth  therein ("CBS
Merger");

         WHEREAS,  the Restated Merger  Agreement  provides that,  under certain
circumstances,  the  distribution  of ARS' tower  business to the holders of ARS
Common  Stock may be effect  separate  and apart  from  consummation  of the CBS
Merger  through  the  merger  of ATS  Mergercorp  with and into ARS (the  "Tower
Merger"); and

         WHEREAS,  the  Boards  of  Directors  of ARS  and ATS  Mergercorp  have
determined  that the Tower Merger on the terms and  conditions set forth in this
Agreement  and Plan of  Merger  (this  "Agreement")  is  consistent  with and in
furtherance of the long-term  business  strategy of each, and is fair to, and in
the best interests of, ATS Mergercorp, ARS and the stockholders of each; and

         WHEREAS, ARS and ATS Mergercorp intend that the Tower Merger shall, for
federal  income tax  purposes,  qualify as a tax-free  reorganization  under the
provisions of Section 368(a) of the Code; and

         WHEREAS,  the  Boards  of  Directors  of ARS  and ATS  Mergercorp  have
approved  and  adopted  this  Agreement  and the Tower  Merger  and the Board of
Directors  of  ARS  has  directed  that  this  Agreement  be  submitted  to  its
stockholders  for their adoption and approval;  ARS, as the sole  stockholder of
ATS Mergercorp has approved and adopted this Agreement;

         NOW,   THEREFORE,   in   consideration   of  the   premises   and   the
representations, warranties, covenants and agreements herein contained and other
valuable   consideration,   the   receipt  and   adequacy   whereof  are  hereby
acknowledged,  the  parties  hereto  hereby,  intending  to  be  legally  bound,
represent, warrant, covenant and agree as follows:

                                    ARTICLE 1

                                  DEFINED TERMS

         As used  herein,  unless  the  context  otherwise  requires,  the terms
defined in  Appendix A shall have the  respective  meanings  set forth  therein.
Terms defined in the singular  shall have a comparable  meaning when 

                                                     


<PAGE>

used in the plural,  and vice versa,  and the  reference  to any gender shall be
deemed to include all genders. Unless otherwise defined or the context otherwise
clearly requires,  terms for which meanings are provided in this Agreement shall
have such meanings when used in each Collateral Document executed or required to
be executed  pursuant  hereto or thereto or  otherwise  delivered,  from time to
time,  pursuant hereto or thereto.  References to "hereof,"  "herein" or similar
terms are  intended to refer to the  Agreement  as a whole and not a  particular
section,  and  references  to "this  Section" of "this  Article" are intended to
refer to the entire section or article and not a particular  subsection thereof.
The term "either party" shall, unless the context otherwise  requires,  refer to
ARS and ATS Mergercorp.

                                    ARTICLE 2

                                THE TOWER MERGER

         2.1 The Tower Merger.  Upon the terms and subject to the conditions set
forth in this Agreement, and in accordance with the Delaware General Corporation
Law (the "DCL"),  at the Effective Time, ATS Mergercorp shall be merged with and
into  ARS.  As a result of the  Tower  Merger,  the  separate  existence  of ATS
Mergercorp  shall cease and ARS shall  continue as the surviving  corporation in
the  Tower  Merger   (sometimes   referred  to,  as  such,  as  the   "Surviving
Corporation").

         2.2 Closing.  The closing of the Tower Merger (the "Closing") will take
place, on the Closing Date, at the offices of Sullivan & Worcester LLP, One Post
Office Square, Boston,  Massachusetts,  on the date that is the tenth (10th) day
after the date on which all of the conditions set forth in Article 6 (other than
those  which  require  delivery at the  Closing)  shall have been  satisfied  or
waived,  unless  another  date,  time or place is  agreed to in  writing  by the
parties or provided for herein.  The date on which the Closing  occurs is herein
referred to as the "Closing Date."

         2.3 Effective  Time.  Subject to the provisions of this  Agreement,  as
promptly as  practicable  after the Closing,  the parties hereto shall cause the
Tower  Merger  to  be  consummated  by  filing  a  certificate  of  merger  (the
"Certificate of Merger") and any related filings required under the DCL with the
Secretary  of State of the State of  Delaware.  The Tower  Merger  shall  become
effective at such time as such  documents  are duly filed with the  Secretary of
State of the State of  Delaware  or at such later time as is  specified  in such
documents (the "Effective Time").

         2.4 Effect of the Tower Merger.  From and after the Effective Time, the
Surviving  Corporation  shall  possess  all the rights,  privileges,  powers and
franchises and be subject to all of the restrictions, disabilities and duties of
ATS  Mergercorp  and ARS, and the Tower Merger shall  otherwise have the effects
provided for under the DCL.

         2.5  Certificate  of   Incorporation.   The  Restated   Certificate  of
Incorporation of ARS in effect at the Effective Time shall be the Certificate of
Incorporation  of the Surviving  Corporation  unless amended in accordance  with
Applicable Law.

         2.6 Bylaws.  The bylaws of ARS in effect at the Effective Time shall be
the  bylaws of the  Surviving  Corporation  unless  amended in  accordance  with
Applicable Law.

         2.7 Directors and Officers.  From and after the Effective  Time,  until
successors  are duly elected or appointed and  qualified,  or upon their earlier
resignation or removal,  in accordance with Applicable Law, 


                                       -2-


<PAGE>

(a) the  directors of ARS at the  Effective  Time shall be the  directors of the
Surviving  Corporation,  and (b) the officers of ARS at the Effective Time shall
be the officers of the Surviving Corporation.

                                    ARTICLE 3

                 CONVERSION OF SHARES; EXCHANGE OF CERTIFICATES

         3.1  Conversion of Capital Stock.  At the Effective  Time, by virtue of
the Tower Merger and without any action on the part of ATS  Mergercorp or ARS or
their respective stockholders:

         (a) Each share of the 113/8% Series B Cumulative Exchangeable Preferred
Stock, par value $.01 per share, of ARS (the "ARS Cumulative  Preferred  Stock")
issued and  outstanding  immediately  prior to the  Effective  Time shall remain
outstanding;

         (b) Each share of the 7% Convertible  Exchangeable Preferred Stock, par
value $.01 per share, of ARS (the "ARS Convertible  Preferred Stock") issued and
outstanding immediately prior to the Effective Time shall remain outstanding;

         (c) Each share of Class A Common Stock,  par value $.01 per share ("ARS
Class A Common Stock"),  each share of Class B Common Stock,  par value $.01 per
share ("ARS Class B Common  Stock") and each share of Class C Common Stock,  par
value $.01 per share ("ARS Class C Common  Stock"),  of ARS  (collectively,  the
"ARS Common Stock"),  issued and outstanding  immediately prior to the Effective
Time shall,  by virtue of the Tower Merger and without any action on the part of
the holder thereof, be converted into the right to receive:

                  (i) one  share of  Common  Stock,  par  value  $.01 per  share
         ("Tower Common Stock") of American Tower Systems Corporation ("American
         Tower Systems"),  with (i) each share of ARS Class A Common Stock being
         converted  into the right to receive one share of Class A Common Stock,
         par value $.01 per share  ("Tower  Class A Common  Stock") of  American
         Tower  Systems,  (ii)  each  share of ARS  Class B Common  Stock  being
         converted  into the right to receive one share of Class B Common Stock,
         par value $.01 per share  ("Tower  Class B Common  Stock") of  American
         Tower  Systems,  and  (iii)  each  share of ARS  Class C  Common  being
         converted  into the right to receive one share of Class C Common Stock,
         par value $.01 per share  ("Tower  Class C Common  Stock") of  American
         Tower Systems; and

                  (ii) a fraction (the "ARS Conversion  Fraction") of a share of
         ARS Common  Stock of the same  class as the class of ARS  Common  Stock
         being converted,  (i) the numerator of which is the difference  between
         (A) the denominator  and (B) the value  (determined as set forth below)
         of one share of Tower  Class A Common  Stock  immediately  prior to the
         Effective  Time,  and  (ii)  the  denominator  of  which  is the  value
         (determined  as set  forth  below)  of one  share of ARS Class A Common
         Stock  immediately  prior to the Effective Time (the  consideration set
         forth in  paragraph  (a) above  and this  paragraph  (b)  being  herein
         collectively referred to as the "Merger Consideration").

For  purposes of  determining  the value of the ARS Class A Common Stock and the
Tower  Common  Stock  immediately  prior to the  Effective  Time  the  following
principles shall apply:

                  (x) each share of ARS Class A Common  Stock shall be valued at
         an amount equal to the average  closing  sales price of the ARS Class A
         Common Stock on the New York Stock  Exchange (the 


                                       -3-


<PAGE>

         "NYSE"),  as  reported  by the Wall  Street  Journal,  for the ten (10)
         consecutive trading days immediately  preceding the second trading date
         prior to the Effective Time; and

                  (y) each share of Tower  Class A Common  Stock shall be valued
         at the amount determined in good faith by the ARS Board of Directors to
         be its fair market value immediately prior to the Effective Time.

         (d)  Each  share of  Common  Stock,  par  value  $.01 per  share of ATS
Mergercorp (the "ATS Mergercorp Common Stock") owned by ARS immediately prior to
the Effective Time shall automatically be canceled and extinguished  without any
conversion thereof and no payment shall be made with respect thereto.

         (e) The  shares of ARS Common  Stock  owned by ARS as  treasury  shares
immediately  prior to the Effective Time shall  automatically,  by virtue of the
Tower  Merger and  without any action on the part of ARS,  be  converted  into a
number of shares of ARS Common  Stock of the same  class  equal to the number of
shares owned by American  immediately  prior to the Effective Time multiplied by
the ARS Conversion Fraction.

         As a result of the Tower  Merger and  without any action on the part of
the holder thereof,  at the Effective Time all shares of ARS Common Stock issued
and outstanding  shall cease to be outstanding and shall be canceled and retired
and shall cease to exist,  and each  holder of shares of ARS Common  Stock shall
thereafter  cease to have any rights  with  respect to such shares of ARS Common
Stock, except the right to receive,  without interest,  the Merger Consideration
and cash for  fractional  shares  of ARS  Common  Stock in  accordance  with the
provisions of Section  3.2(d) upon the  surrender of a certificate  representing
such shares of ARS Common Stock.

         3.2 Exchange of Certificates.

         (a) Pursuant to an  agreement  reasonably  satisfactory  to ARS and ATS
Mergercorp  (the "Exchange  Agent  Agreement") to be entered into at or prior to
the Closing Date between ARS, ATS  Mergercorp and the transfer agent for the ARS
Common Stock (the "Exchange Agent"),  at or immediately  following the Effective
Time, ARS shall deposit or cause to be deposited in trust for the benefit of the
ARS common  stockholders  shares of Tower  Class A Common  Stock,  Tower Class B
Common Stock and Tower Class C Common Stock  representing  the aggregate  Merger
Consideration  to which  holders of ARS Common  Stock  shall be  entitled at the
Effective Time pursuant to the provisions of this Article.

         (b) Not less than five (5) business  days  subsequent  to the Effective
Time, the Exchange Agent shall mail to each holder of record of a certificate or
certificates   that   immediately   prior  to  the  Effective  Time  represented
outstanding  shares of ARS  Common  Stock (the  "Certificates")  (i) a letter of
transmittal  (which shall specify that delivery  shall be effected,  and risk of
loss and title to the Certificates  shall pass, only upon actual delivery of the
Certificates to the Exchange Agent) and (ii)  instructions  for use in effecting
the  surrender of the  Certificates  in exchange for  certificates  representing
shares of ARS Common Stock and Tower Class A Common Stock,  Tower Class B Common
Stock and Tower Class C Common  Stock and cash in lieu of  fractional  shares as
hereinafter  provided.  Upon surrender of Certificates  for  cancellation to the
Exchange  Agent,  together with a duly executed  letter of transmittal  and such
other documents as the Exchange Agent shall  reasonably  require,  the holder of
such  Certificates  shall be  entitled  to receive in  exchange  therefor  (i) a
certificate  representing  that number of whole shares of ARS Common Stock to be
received pursuant to the provision of Section  3.1(c)(ii),  (ii) cash in lieu of
fractional shares as hereinafter  provided and (iii)  certificates  representing
the number of shares of Tower Class A Common  Stock,  Tower Class B Common Stock
and 
                                       -4-


<PAGE>

Tower  Class  C  Common  Stock  into  which  the  shares  of ARS  Common  Stock,
theretofore  represented by the  Certificates  so  surrendered,  shall have been
converted pursuant to the provisions of Section 3.1(c)(i),  and the Certificates
so surrendered  shall be canceled.  Notwithstanding  the foregoing,  neither the
Exchange Agent nor any party hereto shall be liable to a holder of shares of ARS
Common  Stock  for any  shares  of ARS  Common  Stock or Tower  Common  Stock or
dividends or distributions  thereon  delivered to a public official  pursuant to
applicable abandoned property, escheat or similar Laws.

         (c)  Promptly  following  the date  which is six (6)  months  after the
Closing Date,  the Exchange  Agent shall  deliver to ARS all cash,  certificates
(including  any ARS Common Stock and ATS  Mergercorp  Class A Common  Stock) and
other documents in its possession relating to the transactions described in this
Agreement,  and the Exchange  Agent's duties shall terminate.  Thereafter,  each
holder  of a  Certificate  may  surrender  such  Certificate  to  the  Surviving
Corporation and (subject to applicable  abandoned property,  escheat and similar
Laws) receive in exchange therefor the Tower Merger  Consideration to which such
holder is entitled, without any interest thereon. Notwithstanding the foregoing,
neither the  Exchange  Agent nor any party hereto shall be liable to a holder of
ARS Common Stock for any ARS Common  Stock or Tower Common Stock  delivered to a
public official pursuant to applicable  abandoned  property,  escheat or similar
Laws.

         (d) No  certificates  or scrip  representing  fractional  shares of ARS
Common Stock shall be issued upon the  surrender  for exchange of  Certificates,
and such fractional  share interests shall not entitle the owner thereof to vote
or to any rights of a stockholder of ARS. As promptly as  practicable  following
the Effective  Time,  the Exchange  Agent shall  determine the excess of (i) the
number of shares of ARS Common  Stock  delivered  to the  Exchange  Agent by ARS
pursuant to Section 3.2(a) over (ii) the aggregate number of whole shares of ARS
Common  Stock to be  distributed  to holders  of the  Certificates  pursuant  to
Section  3.2(b) (such excess being herein called the "Excess  Shares").  As soon
after the Effective Time as  practicable,  the Exchange  Agent, as agent for the
holders of the  Certificates,  shall sell the Excess  Shares at then  prevailing
prices on the NYSE all in the manner provided in this Section 3.2((d).  The sale
of the Excess Shares by the Exchange Agent shall be executed on the NYSE through
one or more member  firms of the NYSE and shall be executed in round lots to the
extent  practicable.  The  proceeds  from  such  sale  or  sales  available  for
distribution to the holders of Certificates shall be reduced by the compensation
payable to the Exchange Agent and the expenses  incurred by the Exchange  Agent,
in each  case,  in  connection  with  such sale or sales of the  Excess  Shares,
including  all  related  commissions,  transfer  taxes and  other  out-of-pocket
transaction  costs.  Until  the net  proceeds  of such  sale or sales  have been
distributed  to the holders of the  Certificates,  the Exchange Agent shall hold
such proceeds in trust for the holders of the  Certificates  (the "Common Shares
Trust").  The Exchange  Agent shall  determine  the portion of the Common Shares
Trust to which  each  holder of a  Certificate  shall be  entitled,  if any,  by
multiplying  the amount of the  aggregate  net  proceeds  comprising  the Common
Shares  Trust  by a  fraction,  the  numerator  of which  is the  amount  of the
fractional  share interest to which such holder of a Certificate is entitled and
the denominator of which is the aggregate  amount of fractional  share interests
to which all holders of the  Certificates  are entitled.  As soon as practicable
after the  determination of the amount of cash, if any, to be paid to holders of
the Certificates in lieu of any fractional  share interests,  the Exchange Agent
shall make  available  such amounts,  without  interest,  to such holders of the
Certificates  who have  surrendered  their  Certificates in accordance with this
Article III.

         (e) If the Tower Merger Consideration (or any portion thereof) is to be
paid to a Person other than the Person in whose name the Certificate surrendered
in exchange  therefor is  registered,  it shall be a condition to the payment of
the Tower Merger  Consideration  that the  Certificate so  surrendered  shall be
properly  endorsed or accompanied by appropriate  stock powers (with  signatures
guaranteed in accordance with the transmittal form) and otherwise in proper form
for  transfer,  that  such  transfer  otherwise  be proper  and that the  Person
requesting  such transfer pay to the Exchange  Agent any transfer or other Taxes
payable by reason of


                                       -5-


<PAGE>

the foregoing or establish to the  satisfaction  of the Exchange Agent that such
Taxes have been paid or are not required to be paid.

         (f) In the event  any  Certificate  shall  have  been  lost,  stolen or
destroyed,  upon the making of an affidavit of that fact by the Person  claiming
such  Certificate  to be lost,  stolen or  destroyed  and  subject to such other
reasonable conditions as the Board of Directors of the Surviving Corporation may
impose, the Surviving  Corporation shall issue in exchange for such lost, stolen
or destroyed  Certificate the Tower Merger Consideration  deliverable in respect
thereof as determined in accordance  with this Article.  When  authorizing  such
issue of the Tower  Merger  Consideration  in  exchange  therefor,  the Board of
Directors of the Surviving Corporation may, in its discretion and as a condition
precedent to the  issuance  thereof,  require the owner of such lost,  stolen or
destroyed  Certificate to give the Surviving  Corporation a bond or other surety
in such sum as it may reasonably  direct as indemnity against any Claim that may
be made  against  the  Surviving  Corporation  with  respect to the  Certificate
alleged to have been lost, stolen or destroyed.

         (g)  Notwithstanding  any  other  provisions  of  this  Agreement,   no
dividends or other distributions declared after the Effective Time on ARS Common
Stock  shall be paid with  respect to any whole  shares of ARS  Common  Stock or
Tower  Common Stock  represented  by a  Certificate  until such  Certificate  is
surrendered for exchange as provided herein. Subject to the effect of Applicable
Laws,  following  surrender of any such Certificate,  there shall be paid to the
holder of the  shares of ARS  Common  Stock and  Tower  Common  Stock  issued in
exchange  therefor,  without  interest,  (i) at the time of such surrender,  the
amount  of  dividends  or other  distributions  with a  record  date  after  the
Effective  Time  theretofore  payable  with  respect to such whole shares of ARS
Common Stock or Tower Common Stock,  as the case may be, and not paid,  less the
amount of any withholding taxes which may be required  thereon,  and (ii) at the
appropriate  payment date, the amount of dividends or other distributions with a
record date after the  Effective  Time but prior to surrender and a payment date
subsequent to surrender  payable with respect to such whole shares of ARS Common
Stock or  Tower  Common  Stock,  as the case  may be,  less  the  amount  of any
withholding taxes which may be required thereon.

         (h) ARS  shall  be  entitled  to,  or shall be  entitled  to cause  the
Exchange Agent to, deduct and withhold from the consideration  otherwise payable
pursuant  to this  Agreement  to any holder of shares of ARS  Common  Stock such
amounts as are required to be deducted  and withheld  with respect to the making
of such payment under the Code, or any provision of state,  local or foreign tax
law. To the extent that amounts are so withheld by ARS or the Exchange Agent, as
the case may be, such withheld amounts shall be treated for all purposes of this
Agreement as having been paid to the holder of the shares of ARS Common Stock in
respect of which such deduction and  withholding was made by ARS or the Exchange
Agent.


                                    ARTICLE 4

                REPRESENTATIONS AND WARRANTIES OF ATS MERGERCORP

         ATS Mergercorp hereby represents, warrants and covenants to, and agrees
with, ARS as follows:

         (a) ATS Mergercorp is a corporation duly incorporated, validly existing
and in good standing under the laws of the State of Delaware,  has all requisite
power  and  authority  (corporate  and  other)  to own or hold  under  lease its
properties  and to  conduct  its  business  as now  conducted  and as  presently
proposed to be conducted, with full power and authority (corporate and other) to
carry on the business in which it is 

                                       -6-


<PAGE>

engaged,  except  where the  failure to be so  qualified  and in good  standing,
individually  or in the aggregate,  is not reasonably  likely to have a Material
Adverse Effect on ATS Mergercorp.

         (b) ATS Mergercorp has all requisite power and authority (corporate and
other) to execute,  deliver and perform its obligations under this Agreement and
each Collateral  Document  executed or required to be executed by ATS Mergercorp
pursuant hereto or thereto or to consummate the Tower Merger, and the execution,
delivery and performance of this Agreement and each Collateral Document executed
or required to be executed  pursuant hereto or thereto have been duly authorized
by all requisite corporate or other action on the part of ATS Mergercorp,  other
than the approval of the sole stockholder of ATS Mergercorp contemplated by this
Agreement. This Agreement has been duly executed and delivered by ATS Mergercorp
and  constitutes,  and each  Collateral  Document  executed  or  required  to be
executed  pursuant  hereto or thereto or to  consummate  the Tower  Merger  when
executed and  delivered by ATS  Mergercorp  will  constitute,  valid and binding
obligations of ATS Mergercorp,  enforceable in accordance with their  respective
terms, except as such  enforceability may be limited by bankruptcy,  moratorium,
insolvency  and similar laws  affecting the rights and remedies of creditors and
obligations  of debtors  generally  and by  general  principles  of equity.  The
provisions  of Section  203 of the DCL will not apply to this  Agreement  or the
Tower Merger.  As of the date hereof,  the Board of Directors of ATS Mergercorp,
at a meeting duly called and held at which a quorum was present throughout,  has
unanimously (i) determined that this Agreement and the transactions contemplated
hereby,  including without  limitation the Tower Merger,  are fair to and in the
best  interests  of the  holder  of the ATS  Mergercorp  Common  Stock  and have
approved the same, and (ii) resolved to recommend  that the sole  stockholder of
ATS Mergercorp approve this Agreement and the transactions  contemplated hereby,
including without limitation the Tower Merger.

         (c) Except for such consents, the failure of which to obtain would not,
individually  or in the  aggregate,  be  reasonably  likely  to have a  Material
Adverse Effect on ATS  Mergercorp,  the execution and delivery by ATS Mergercorp
of this  Agreement  and any  Collateral  Document  executed  or  required  to be
executed by it pursuant hereto or thereto,  do not, and the  consummation by ATS
Mergercorp of the Tower Merger and  compliance  with the terms,  conditions  and
provisions hereof or thereof by ATS Mergercorp will not:

                  (i) conflict  with,  or result in a breach or violation of, or
         constitute a default under,  any Organic  Document of ATS Mergercorp or
         any Applicable Law applicable to ATS  Mergercorp,  or conflict with, or
         result in a breach or violation of, or constitute a default  under,  or
         permit the  acceleration  of any obligation or liability in, or but for
         any  requirement  of the  giving of notice or  passage  of time or both
         would  constitute  such a conflict  with,  breach or  violation  of, or
         default under, or permit any such acceleration in, any Indebtedness for
         Money Borrowed of ATS Mergercorp, except for such conflicts,  breaches,
         violations  or  accelerations  that would not,  individually  or in the
         aggregate,  be reasonably  likely to have a Material  Adverse Effect on
         ATS Mergercorp; or

                  (ii)  result in or permit the  creation or  imposition  of any
         Lien upon any property now owned or leased by ATS Mergercorp; or

                  (iii) require any  Governmental  Authorization or Governmental
         Filing or Private Autho rization, except for the FCC Consents,  filings
         under the  Hart-Scott-Rodino  Act, and other filing  requirements under
         Applicable Law in connection with the consummation of the Tower Merger.



                                       -7-


<PAGE>

                                    ARTICLE 5

                      REPRESENTATIONS AND WARRANTIES OF ARS

         ARS hereby represents,  warrants and covenants to, and agrees with, ATS
Mergercorp as follows:

         (a) ARS is a corporation  duly  incorporated,  validly  existing and in
good standing under the laws of the State of Delaware,  has all requisite  power
and authority  (corporate  and other) to own or hold under lease its  properties
and to conduct its business as now  conducted  and as  presently  proposed to be
conducted,  with full power and authority  (corporate and other) to carry on the
business in which it is engaged,  except where the failure to be so qualified or
in good standing,  individually or in the aggregate, is not reasonably likely to
have a Material Adverse Effect on ARS.

         (b) ARS has all requisite power and authority  (corporate and other) to
execute,  deliver and  perform its  obligations  under this  Agreement  and each
Collateral  Document  executed or required to be executed by ARS pursuant hereto
or thereto or to consummate the Tower Merger,  and the  execution,  delivery and
performance of this Agreement and each Collateral  Document executed or required
to be  executed  pursuant  hereto or thereto  have been duly  authorized  by all
requisite  corporate or other action on the part of ARS, other than the approval
of the ARS stockholders  contemplated by this Agreement. This Agreement has been
duly executed and delivered by ARS and constitutes, and each Collateral Document
executed or required to be executed  pursuant hereto or thereto or to consummate
the Tower Merger when executed and delivered by ARS will  constitute,  valid and
binding  obligations  of ARS,  enforceable in accordance  with their  respective
terms, except as such  enforceability may be limited by bankruptcy,  moratorium,
insolvency  and similar laws  affecting the rights and remedies of creditors and
obligations  of debtors  generally  and by  general  principles  of equity.  The
provisions  of Section  203 of the DCL will not apply to this  Agreement  or the
Tower Merger. As of the date hereof, the Board of Directors of ARS, at a meeting
duly called and held at which a quorum was present  throughout,  has unanimously
(i) determined  that this Agreement and the  transactions  contemplated  hereby,
including  without  limitation  the  Tower  Merger,  are fair to and in the best
interests of the holders of the ARS Common Stock and have approved the same, and
(ii) resolved to recommend that the ARS stockholders  approve this Agreement and
the transactions  contemplated  hereby,  including without  limitation the Tower
Merger.

         (c) Except for  consents  and  authorizations,  the failure of which to
obtain,  would not,  individually or in the aggregate,  be reasonably  likely to
have a Material Adverse Effect on ARS, the execution and delivery by ARS of this
Agreement and any Collateral  Document executed or required to be executed by it
pursuant  hereto or thereto  do not,  and the  consummation  by ARS of the Tower
Merger,  and compliance  with the terms,  conditions  and  provisions  hereof or
thereof by ARS will not:

                  (i) conflict  with,  or result in a breach or violation of, or
         constitute  a  default  under,  any  Organic  Document  of  ARS  or any
         Applicable  Law,  or will  conflict  with,  or  result  in a breach  or
         violation of, or constitute a default under, or permit the acceleration
         of any  obligation or liability in, or but for any  requirement  of the
         giving of notice or  passage of time or both  would  constitute  such a
         conflict with,  breach or violation of, or default under, or permit any
         such  acceleration  in, any  Indebtedness  for Money  Borrowed  of ARS,
         except for such conflicts,  breaches,  violations or accelerations that
         would not,  individually or in the aggregate,  be reasonably  likely to
         have a Material Adverse Effect on ARS; or



                                       -8-


<PAGE>

                  (ii)  result in or permit the  creation or  imposition  of any
         Lien upon any property now owned or leased by ARS; or

                  (iii) require any  Governmental  Authorization or Governmental
         Filing or Private Autho rization, except for the FCC Consents,  filings
         under the  Hart-Scott-Rodino  Act, and other filing  requirements under
         Applicable Law in connection with the consummation of the Tower Merger.


                                    ARTICLE 6

                               CLOSING CONDITIONS

         6.1 Conditions to Obligations of Each Party to Effect the Tower Merger.
The  respective  obligations  of each  party to effect the Tower  Merger  shall,
except as hereinafter  provided in this Section,  be subject to the satisfaction
at or prior to the Closing Date of the following conditions, any or all of which
may be waived, in whole or in part, to the extent permitted by Applicable Law:

                  (a) The CBS Merger  shall not have been  consummated  by 11:59
         p.m. on May 31, 1998;

                  (b) This Agreement and the  transactions  contemplated  hereby
         shall  have been  approved  and  adopted by the  requisite  vote of the
         stockholders of ARS and ATS Mergercorp under Applicable Law;

                  (c) The waiting period  applicable to the  consummation of the
         Tower Merger under the Hart-Scott-Rodino Act shall have expired or been
         terminated; and

                  (d) No Authority of competent jurisdiction shall have enacted,
         issued,  promulgated,  enforced or entered any Law (whether  temporary,
         preliminary or permanent) that remains in effect and restrains, enjoins
         or otherwise prohibits consummation of the Tower Merger.

         6.2 Conditions to Obligations of ATS Mergercorp.  The obligation of ATS
Mergercorp  to effect the Tower Merger shall be subject to the  satisfaction  of
the  following  conditions,  any or all of which may be  waived,  in whole or in
part, to the extent permitted by Applicable Law:

                  (a) The  representations  and  warranties  of ARS set forth in
         this  Agreement  shall  be  true  and  correct  as of the  date of this
         Agreement  and as of the  Closing  Date as though made on and as of the
         Closing  Date  except  (i)  to  the  extent  such  representations  and
         warranties  expressly  speak as of an earlier  date (in which case such
         representations  and  warranties  shall be true and  correct as of such
         earlier  date)  and  (ii)  to the  extent  that  the  failure  of  such
         representations and warranties to be true and correct,  individually or
         in the  aggregate,  would not have a  Material  Adverse  Effect on ARS;
         provided,   however,   that  for  the  purpose  of  this  clause  (ii),
         representations  and  warranties  that are qualified as to  materiality
         (including  by  reference to "Material  Adverse  Effect")  shall not be
         deemed to be so qualified;

                  (b) ARS shall have  performed  in all  material  respects  all
         obligations  required to be performed by it under this  Agreement at or
         prior to the Closing Date; and

                                       -9-


<PAGE>

                 (c) Between the date of this  Agreement  and the Closing Date,
         except as  contemplated  by this  Agreement,  as the case may be, there
         shall not have occurred and be continuing  any Material  Adverse Change
         in ARS.

         6.3  Conditions to  Obligations of ARS. The obligation of ARS to effect
the  Tower  Merger  shall  be  subject  to the  satisfaction  of  the  following
conditions,  any or all of which  may be  waived,  in  whole or in part,  to the
extent permitted by Applicable Law:

                  (a) The  representations  and warranties of ATS Mergercorp set
         forth in this  Agreement  shall be true and  correct  as of the date of
         this  Agreement  and as of the Closing Date as though made on and as of
         the  Closing  Date except (i) to the extent  such  representations  and
         warranties  expressly  speak as of an earlier  date (in which case such
         representations  and  warranties  shall be true and  correct as of such
         earlier  date)  and  (ii)  to the  extent  that  the  failure  of  such
         representations and warranties to be true and correct,  individually or
         in the  aggregate,  would  not have a  Material  Adverse  Effect on ATS
         Mergercorp;  provided,  however,  that for the  purpose of this  clause
         (ii),   representations   and  warranties  that  are  qualified  as  to
         materiality (including by reference to "Material Adverse Effect") shall
         not be deemed to be so qualified;

                  (b)  ATS  Mergercorp  shall  have  performed  in all  material
         respects  all  obligations  required to be  performed  by it under this
         Agreement at or prior to the Closing Date; and

                  (c) The Board of Directors of ARS shall not have determined to
         abandon the Tower Merger.


                                    ARTICLE 7

                        TERMINATION, AMENDMENT AND WAIVER

         7.1 Termination. This Agreement shall terminate automatically,  without
any action of either of the parties, upon consummation of the CBS Merger and may
be  terminated at any time prior to the Closing  Date,  whether  before or after
approval by the stockholders of ARS:

                  (a) by mutual written consent of ARS and ATS Mergercorp;

                  (b) by  either  ATS  Mergercorp  or ARS  if any  Authority  of
         competent  jurisdiction  shall  have  enacted,   issued,   promulgated,
         enforced  or  entered  any  Law  that  shall  have  become   final  and
         nonappealable  and  that  restrains,  enjoins  or  otherwise  prohibits
         consummation  of the  Tower  Merger,  unless  the  party  seeking  such
         restraint  injunction or prohibition  or any Affiliate  thereof was the
         terminating party; and

                  (c) by ARS in the event it  determines  to  abandon  the Tower
         Merger  as  not  being  in  the  best   interests  of  the  ARS  common
         stockholders.

The term "Termination  Date" shall mean December 31, 1998, as such date may from
time to time be extended by mutual agreement of the parties.


                                      -10-


<PAGE>

         7.2 Effect of  Termination.  Except as  provided  in Section 8.3 (Fees,
Expenses and other Payments),  in the event of the termination of this Agreement
pursuant to Section  7.1, or in the event the Tower Merger shall not have become
effective prior to the end of business on the day prior to the Termination Date,
this  Agreement  shall  forthwith  become  void and have no effect,  without any
liability  on the  part of any  party,  or any of its  respective  stockholders,
officers or directors, to the other.


                                    ARTICLE 8

                               GENERAL PROVISIONS

         8.1  Amendment.  This Agreement may be amended from time to time by the
parties  hereto at any time prior to the Closing Date but only by an  instrument
in writing signed by the parties hereto and, subject, to Applicable Law.

         8.2 Waiver. At any time prior to the Closing Date, except to the extent
not permitted by Applicable Law, ATS Mergercorp or ARS may, either  generally or
in a particular instance and either  retroactively or prospectively,  extend the
time for the  performance of any of the  obligations or other acts of the other,
subject,  however,  to the provisions of Section 7.1, waive any  inaccuracies in
the  representations  and  warranties  of the other  contained  herein or in any
document  delivered  pursuant hereto, and waive compliance by the other with any
of the agreements,  covenants,  conditions or other provision  contained herein.
Any such  extension or waiver shall be valid only if set forth in an  instrument
in writing signed by the party or parties to be bound thereby.

         8.3 Fees, Expenses and Other Payments.  All costs and expenses incurred
in connection with the negotiation,  preparation, performance and enforcement of
this Agreement (including all fees and expenses of counsel,  financial advisors,
accountants,  and  other  consultants,  advisors  and  representatives  for  all
activities of such persons  undertaken  pursuant to this Agreement)  incurred by
the parties hereto shall be borne by ARS.

         8.4  Notices.  All  notices  and  other  communications  which  by  any
provision of this Agreement are required or permitted to be given shall be given
in writing  and shall be (a) mailed by  first-class  or  express  mail,  postage
prepaid, or by recognized courier service, (b) sent by telecopy or other form of
rapid  transmission,  confirmed  by mailing  (by first  class or  express  mail,
postage  prepaid,  or by recognized  courier  service)  written  confirmation at
substantially  the  same  time as such  rapid  transmission,  or (c)  personally
delivered to the receiving  party (which if, other than an individual,  shall be
an officer or other responsible party of the receiving party).  All such notices
and communications shall be mailed, sent or delivered as follows:

         (a) If to ATS Mergercorp:

               ATS Mergercorp Merger Corporation
               116 Huntington Avenue
               Boston, Massachusetts 02116
               Attention: Steven B. Dodge, President and Chief Executive Officer
               Telecopier No.:  (617) 375-7575


                                      -11-


<PAGE>


               with a copy to:
               
               Sullivan & Worcester LLP
               One Post Office Square
               Boston, Massachusetts 02109
               Attention:  Norman A. Bikales, Esq.
               Telecopier No.:  (617) 338-2880

         (b) If to ARS:

               American Radio Systems Corporation
               116 Huntington Avenue
               Boston, Massachusetts 02116
               Attention: Steven B. Dodge, President and Chief Executive Officer
               Telecopier No.:  (617) 375-7575

               with a copy to:
               
               Sullivan & Worcester LLP
               One Post Office Square
               Boston, Massachusetts 02109
               Attention:  Norman A. Bikales, Esq.
               Telecopier No.:  (617) 338-2880

or to such other person(s),  telex or facsimile  number(s) or address(es) as the
party to receive any such communication or notice may have designated by written
notice to the other party.

         8.5  Specific  Performance;  Other  Rights  and  Remedies.  Each  party
recognizes and agrees that in the event the other party should refuse to perform
any of its  obligations  under this  Agreement or any Collateral  Document,  the
remedy at law would be inadequate and agrees that for breach of such provisions,
each party shall,  in addition to such other  remedies as may be available to it
at law or in equity or as  provided  in Article  7, be  entitled  to  injunctive
relief and to enforce its rights by an action for  specific  performance  to the
extent permitted by Applicable Law. Each party hereby waives any requirement for
security  or the post ing of any bond or other  surety  in  connection  with any
temporary or permanent award of injunctive, mandatory or other equitable relief.
Nothing  herein  contained  shall be  construed as  prohibiting  each party from
pursuing any other remedies  available to it under Applicable Law or pursuant to
the provisions of this Agreement for such breach or threatened breach, including
without limitation the recovery of damages,  including, to the extent awarded in
any Legal Action,  punitive,  incidental and  consequential  damages  (including
without  limitation  damages  for  diminution  in value and loss of  anticipated
profits) or any other measure of damages permitted by Applicable Law.

         8.6 Survival of Representations,  Warranties, Covenants and Agreements.
None of the  representations  and warranties in this Agreement shall survive the
Tower Merger, and after effectiveness of the Tower Merger neither of the parties
or their respective  officers,  directors or stockholders shall have any further
obligation with respect thereto.

                                      -12-


<PAGE>

         8.7  Severability.  If any term or provision of this Agreement shall be
held or deemed  to be, or shall in fact be,  invalid,  inoperative,  illegal  or
unenforceable  as  applied  to  any  particular  case  in  any  jurisdiction  or
jurisdictions,  or in  all  jurisdictions  or  in  all  cases,  because  of  the
conflicting of any provision with any  constitution or statute or rule of public
policy or for any other reason,  such circumstance  shall not have the effect of
rendering the provision or provisions in question invalid, inoperative,  illegal
or unenforceable in any other  jurisdiction or in any other case or circumstance
or of rendering any other  provision or  provisions  herein  contained  invalid,
inoperative,  illegal or  unenforceable to the extent that such other provisions
are not themselves actually in conflict with such constitution,  statute or rule
of public policy, but this Agreement shall be reformed and construed in any such
jurisdiction or case as if such invalid,  inoperative,  illegal or unenforceable
provision had never been contained herein and such provision reformed so that it
would be valid,  operative and  enforceable to the maximum  extent  permitted in
such jurisdiction or in such case.  Notwithstanding the foregoing,  in the event
of any such  determination,  the parties shall negotiate in good faith to modify
this Agreement so as to effect the original  intent of the parties as closely as
possible to the fullest  extent  permitted by  Applicable  Law in an  acceptable
manner to the end that the Tower  Merger is  fulfilled  and  consummated  to the
maximum extent possible.

         8.8   Counterparts.   This   Agreement   may  be  executed  in  several
counterparts,  each of  which  shall be  deemed  an  original,  but all of which
together shall constitute one and the same  instrument,  binding upon all of the
parties. In pleading or proving any provision of this Agreement, it shall not be
necessary to produce more than one of such counterparts.

         8.9 Section Headings.  The headings contained in this Agreement are for
reference  purposes  only  and  shall  not in any  way  affect  the  meaning  or
interpretation of this Agreement.

         8.10  Governing  Law. The validity,  interpretation,  construction  and
performance of this Agreement  shall be governed by, and construed in accordance
with,  the  Applicable  Laws of the United States of America and the laws of the
State of Delaware  applicable to contracts made and performed in such State and,
in any event,  without giving effect to any choice or conflict of laws provision
or rule that would cause the  application  of domestic  substantive  laws of any
other jurisdiction.  Anything in this Agreement to the contrary notwithstanding,
in the event of any dispute between the parties which results in a Legal Action,
the prevailing party shall be entitled to receive from the non-prevailing  party
reimbursement for reasonable legal fees and expenses incurred by such prevailing
party in such Legal Action.

         8.11 Further Acts. Each party agrees that at any time, and from time to
time, before and after the consummation of the transactions contemplated by this
Agreement,  it  will do all  such  things  and  execute  and  deliver  all  such
Collateral  Documents  and other  assurances,  as the other party or its counsel
reasonably  deems  necessary  or  desirable  in order to carry out the terms and
conditions of this  Agreement  and the  transactions  contemplated  hereby or to
facilitate  the enjoyment of any of the rights  created  hereby or to be created
hereunder.

         8.12 Entire Agreement;  No Other  Representations  or Agreements.  This
Agreement  (together  with the other  Collateral  Documents  delivered  or to be
delivered  in  connection  herewith)  constitutes  the entire  agreement  of the
parties  with  respect to the subject  matter  hereof and  supersedes  all prior
agreements,   arrangements,   covenants,  promises,  conditions,   undertakings,
inducements, representations, warranties and negotiations, expressed or implied,
oral or written, between the parties, with respect to the subject matter hereof.
Each of the  parties  is a  sophisticated  legal  entity  that  was  advised  by
experienced  counsel and, to the extent it deemed  necessary,  other advisors in
connection with this Agreement. Each of the parties hereby acknowledges that (a)
neither  party has  relied  or will rely in  respect  of this  Agreement  or the
transactions   
                                      -13-


<PAGE>

contemplated hereby upon any document or written or oral information  previously
furnished  to or  discovered  by it or  its  representatives,  other  than  this
Agreement (including the other Collateral Documents) or such of the foregoing as
are delivered at the Closing,  (b) there are no covenants or agreements by or on
behalf  of  either  party  hereto  or  any  of  its  respective   Affiliates  or
representatives  other than those  expressly set forth in this Agreement and the
Collateral  Documents,  and (c) the parties'  respective  rights and obligations
with respect to this Agreement and the events giving rise thereto will be solely
as set forth in this Agreement and the Collateral  Documents.  WITHOUT  LIMITING
THE GENERALITY OF THE FOREGOING,  EACH PARTY HERETO AGREES THAT,  EXCEPT FOR THE
REPRESENTATIONS AND WARRANTIES CONTAINED IN THIS AGREEMENT,  NEITHER ARS NOR ATS
Mergercorp  MAKES ANY  OTHER  REPRESENTATIONS  OR  WARRANTIES,  AND EACH  HEREBY
DISCLAIMS ANY OTHER  REPRESENTATIONS  OR WARRANTIES MADE BY ITSELF OR ANY OF ITS
OFFICERS,  DIRECTORS,  EMPLOYEES,  AGENTS, FINANCIAL AND LEGAL ADVISORS OR OTHER
REPRESENTATIVES, WITH RESPECT TO THE EXECUTION AND DELIVERY OF THIS AGREEMENT OR
THE TRANSACTIONS CONTEMPLATED HEREBY, NOTWITHSTANDING THE DELIVERY OR DISCLOSURE
TO THE  OTHER  OR THE  OTHER'S  REPRESENTATIVES  OF ANY  DOCUMENTATION  OR OTHER
INFORMATION WITH RESPECT TO ANY ONE OR MORE OF THE FOREGOING.

         8.13  Assignment.  This Agreement  shall not be assignable by any party
and any such  assignment  shall be null and void,  except that it shall inure to
the benefit of and be binding  upon any  successor to each party by operation of
Law,  including by way of merger,  consolidation or sale of all or substantially
all of its assets,  and each party may assign its rights and remedies  hereunder
to any bank or other financial  institution  which has loaned funds or otherwise
extended credit to it.

         8.14  Parties in  Interest.  This  Agreement  shall be binding upon and
inure  solely to the benefit of each party and their  permitted  successors  and
assigns,  and nothing in this Agreement,  express or implied,  is intended to or
shall  confer  upon any  Person  any  right,  benefit  or remedy  of any  nature
whatsoever under or by reason of this Agreement, except as otherwise provided in
Section 8.13.







                            [SIGNATURE PAGE FOLLOWS]

                                      -14-


<PAGE>



         IN WITNESS  WHEREOF,  ARS and ATS Mergercorp have caused this Agreement
and Plan of Merger to be  executed,  pursuant to the  authority  and approval of
each of their respective Boards of Directors, as of the date first written above
by their respective officers thereunto duly authorized.

                              American Radio Systems Corporation


                              By: /s/ Steven B. Dodge
                                Name: Steven B. Dodge
                                Title:    Chairman of the Board, President and
                                          Chief Executive Officer

                              ATS Merger Corporation



                              By: /s/ Steven B. Dodge
                                Name: Steven B. Dodge
                                Title: Chairman of the Board, President and
                                       Chief Executive Officer




                                      -15-


<PAGE>



                                                                 APPENDIX A

                                   DEFINITIONS


         Adverse,  Adversely, when used alone or in conjunction with other terms
(including  without  limitation  "Affect," "Change" and "Effect") shall mean any
Event that has adversely  affected or is reasonably  likely to adversely  affect
(a) the  validity or  enforceability  of this  Agreement  or the  likelihood  of
consummation of the Tower Merger,  or (b) the financial  condition or results of
operation of the ATS Mergercorp and its  Subsidiaries,  taken as a whole, or the
ARS and its  Subsidiaries,  taken as a whole, as the case may be, or (c) ARS' or
ATS  Mergercorp',  as the case may be, ability to fulfill its obligations  under
the terms of this Agreement. Notwithstanding the foregoing, and anything in this
Agreement to the contrary  notwithstanding,  neither (i) any Event affecting the
radio  broadcasting  industry or the national or any regional or market  economy
generally.

         Affiliate,  Affiliated shall mean, with respect to any Person,  (a) any
other Person at the time  directly or indirectly  controlling,  controlled by or
under direct or indirect  common  control with such Person,  any other Person of
which such  Person at the time owns,  or has the right to  acquire,  directly or
indirectly,  twenty  percent  (20%) or more of any class of the capital stock or
beneficial  interest,  (c) any other Person  which at the time owns,  or has the
right to acquire,  directly or  indirectly,  twenty percent (20%) or more of any
class of the  capital  stock or  beneficial  interest  of such  Person,  (d) any
executive  officer  or  director  of  such  Person,  (e)  with  respect  to  any
partnership,  joint venture or similar Entity, any general partner thereof,  and
(f) when used with respect to an  individual,  shall  include any member of such
individual's immediate family or a family trust.

         Agreement  shall have the  meaning  given to it in the third  "Whereas"
paragraph and shall include any amendments executed and delivered by the parties
pursuant to the provisions of Section 8.1.

         American  Tower  Systems  shall have the meaning given to it in Section
3.1(c)(i).

         Applicable Law shall mean,  with respect to any Person,  any Law of any
Authority,  whether  domestic or foreign,  to which such Person is subject or by
which it or any of its business or  operations is subject or any of its property
or assets is bound.

         ARS shall have the meaning given to it in the Preamble.

         ARS Class A Common Stock shall have the meaning  given to it in Section
3.1(c).

         ARS Class B Common Stock shall have the meaning  given to it in Section
3.1(c).

         ARS Class C Common Stock shall have the meaning  given to it in Section
3.1(c).

         ARS Common Stock shall have the meaning given to it in Section 3.1(c).

         ARS  Conversion  Fraction shall have the meaning given to it in Section
3.1(c)(ii).

         ARS  Convertible  Preferred Stock shall have the meaning given to it in
Section 3.1(b).

         ARS  Cumulative  Preferred  Stock shall have the meaning given to it in
Section 3.1(a).


                                                     


<PAGE>


         ATS Mergercorp shall have the meaning given to it in the Preamble.

         ATS  Mergercorp  Common  Stock  shall have the  meaning  given to it in
Section 3.1(d).

         Authority shall mean any governmental or quasi-governmental  authority,
whether  administrative,  executive,  judicial,  legislative  or  other,  or any
combination   thereof,   including  without   limitation  any  federal,   state,
territorial,   county,   municipal  or  other   government  or  governmental  or
quasi-governmental agency, arbitrator,  authority,  board, body, branch, bureau,
central bank or comparable  agency or Entity,  commission,  corporation,  court,
department,  instrumentality,  master, mediator, panel, referee, system or other
political unit or  subdivision or other Entity of any of the foregoing,  whether
domestic or foreign.

         CBS  shall  have  the  meaning  given  to it  in  the  first  "Whereas"
paragraph.

         CBS Merger  shall have the meaning  given to it in the first  "Whereas"
paragraph.

         CBS Sub  shall  have the  meaning  given to it in the  first  "Whereas"
paragraph.

         Certificate  of Merger  shall have the  meaning  given to it in Section
2.3.

         Certificates shall have the meaning given to it in Section 3.2(b).

         Closing shall have the meaning given to it in Section 2.2.

         Closing Date shall have the meaning given to it in Section 2.2.

         Code shall mean the Internal  Revenue  Code of 1986,  and the rules and
regulations  thereunder,  all as from time to time in effect,  or any  successor
law,  rules or  regulations,  and any  reference to any  statutory or regulatory
provision  shall be deemed  to be a  reference  to any  successor  statutory  or
regulatory provision.

         Collateral  Document shall mean any agreement,  certificate,  contract,
instrument,  notice,  opinion  or  other  document  delivered  pursuant  to  the
provisions of this Agreement.

         Common  Shares  Trust  shall  have the  meaning  given to it in Section
3.2(d).

         Control (including the terms  "controlled,"  "controlled by" and "under
common control with") means the possession, directly or indirectly or as trustee
or executor,  of the power to direct or cause the direction of the management or
policies of a Person,  or the disposition of such Person's assets or properties,
whether through the ownership of stock, equity or other ownership,  by contract,
arrangement or understanding,  or as trustee or executor,  by contract or credit
arrangement or otherwise.

         DCL shall have the meaning given to it in Section 2.1.

         Effective Time shall have the meaning given to it in Section 2.3.

         Entity shall mean any corporation,  firm, unincorporated  organization,
association,  partnership,  limited  liability  company,  trust  (inter vivos or
testamentary),  estate of a deceased, insane or incompetent individual, business
trust,  joint stock  company,  joint  venture or other  organization,  entity or
business,  whether acting in an individual,  fiduciary or other capacity, or any
Authority.

                                       -2-


<PAGE>


         Event  shall  mean the  existence  or  occurrence  of any act,  action,
activity,  circumstance,  condition,  event,  fact,  failure  to act,  omission,
incident or practice, or any set or combination of any of the foregoing.

         Excess Shares shall have the meaning given to it in Section 3.2(d).

         Exchange Agent shall have the meaning given to it in Section 3.2(a).

         Exchange Agent  Agreement shall have the meaning given to it in Section
3.2(a).

         FCC Consents means actions by the FCC (including the Chief,  Mass Media
Bureau,  acting under delegated  authority) granting its consent to the transfer
of control of the American  FCC  Licenses  for each of the American  Stations to
Mergeparty as  contemplated  by this  Agreement  whether or not such consent has
become a Final Order.

         Governmental  Authorizations  shall  mean all  approvals,  concessions,
consents,   franchises,   licenses,  permits,  plans,  registrations  and  other
authorizations  of all  Authorities,  including the FCC Licenses,  issued by the
FCC, the Federal Aviation  Administration  and any other Authority in connection
with the conduct of business or operations of any of the Stations.

         Governmental  Filings shall mean all filings,  including  franchise and
similar Tax  filings,  and the payment of all fees,  assessments,  interest  and
penalties associated with such filings, with all Authorities.

         Hart-Scott-Rodino  Act  shall  mean  the  Hart-Scott-Rodino   Antitrust
Improvements Act of 1976, and the rules and regulations thereunder,  all as from
time to time in effect,  or any successor  law,  rules or  regulations,  and any
reference to any such statutory or regulatory  provision shall be deemed to be a
reference to any successor statutory or regulatory provision.

         Law shall mean any (a) administrative,  judicial,  legislative or other
action,  code,  consent  decree,  constitution,  decree,  directive,  enactment,
finding, guideline, law, injunction, interpretation, judgment, order, ordinance,
proclamation,  promulgation, regulation, requirement, rule, rule of law, rule of
public policy, settlement agreement, statute, or writ of any Authority, domestic
or foreign; (b) the common law, or other legal or quasi-legal precedent;  or (c)
arbitrator's,    mediator's   or   referee's   award,   decision,   finding   or
recommendation.

         Legal  Action  shall  mean,  with  respect to any  Person,  any and all
litigation or legal or other  actions,  arbitrations,  counterclaims,  hearings,
investigations,  proceedings  or  suits,  at law or in  arbitration,  equity  or
admiralty,  whether or not purported to be brought on behalf of such Person,  by
or before any  Authority,  against such Person or involving any of such Person's
business or assets.

         Lien shall mean any of the  following:  mortgage;  lien  (statutory  or
other) or other  security  agreement,  arrangement  or interest;  hypothecation,
pledge  or  other  deposit  arrangement;  assignment;  charge;  levy;  executory
seizure;   attachment;   garnishment;   encumbrance   (including  any  easement,
exception,  reservation or limitation,  right of way, and the like); conditional
sale,  title  retention  or other  similar  agreement,  arrangement,  device  or
restriction;  any  financing  lease  involving  substantially  the same economic
effect as any of the foregoing;  the filing of any financing statement under the
Uniform Commercial Code or comparable law of any jurisdiction; or restriction on
sale, transfer, assignment, disposition or other alienation.

                                       -3-


<PAGE>


         Material, Materially or materiality for the purposes of this Agreement,
shall, unless specifically stated to the contrary,  be determined without regard
to the fact that various  provisions of this Agreement set forth specific dollar
amounts.

         Merger  shall  have  the  meaning  given to it in the  third  "Whereas"
paragraph.

         Merger  Consideration  shall  have the  meaning  given to it in Section
3.1(e )(ii).

         NYSE shall have the meaning given to it in Section 3.1(c).

         Organic  Document  shall  mean,  with  respect  to a Person  which is a
corporation,  its charter,  its by-laws and all stockholder  agreements,  voting
trusts and similar arrangements applicable to any of its capital stock and, with
respect to a Person which is a  partnership,  its agreement and  certificate  of
partnership,  any  agreements  among  partners,  and any  management and similar
agreements  between the partnership  and any general  partners (or any Affiliate
thereof).

         Person shall mean any natural individual or any Entity.

         Private Authorizations shall mean all approvals, concessions, consents,
franchises,  licenses,  permits,  and other authorizations of all Persons (other
than Authorities) including without limitation those with respect to copyrights,
computer software programs,  patents,  service marks,  trademarks,  trade names,
technology and know-how.

         Regulations  shall mean the federal income tax regulations  promulgated
under  the Code,  as such  Regulations  may be  amended  from time to time.  All
references  herein to specific  sections of the Regulations shall be deemed also
to refer to any  corresponding  provisions  of succeeding  Regulations,  and all
references  to  temporary  Regulations  shall  be  deemed  also to  refer to any
corresponding provisions of final Regulations.

         Representatives shall have the meaning given to it in Section 6.1(a).

         Restated  Merger  Agreement  shall have the meaning  given to it in the
second "Whereas" paragraph.

         Subsidiary shall mean, with respect to a Person,  any Entity a majority
of the capital stock  ordinarily  entitled to vote for the election of directors
of which,  or if no such voting stock is  outstanding,  a majority of the equity
interests of which, is owned directly or indirectly, legally or beneficially, by
such Person or any other Person controlled by such Person.

         Surviving  Corporation  shall have the  meaning  given to it in Section
2.1.

         Tax (and "Taxable,"  which shall mean subject to Tax), shall mean, with
respect to any Person,  (a) all taxes (domestic or foreign),  including  without
limitation any income (net, gross or other, including recapture of any tax items
such as  investment  tax  credits),  alternative  or add-on  minimum tax,  gross
income,  gross receipts,  gains,  sales, use, leasing,  lease, user, ad valorem,
transfer, recording, franchise, profits, property (real or personal, tangible or
intangible),  fuel,  license,  withholding on amounts paid to or by such Person,
payroll,  employment,  unemployment,  social security, excise, severance, stamp,
occupation, premium, environmental or windfall profit tax, custom, duty or other
tax, or other like  assessment or charge of any kind  whatsoever,  together with
any  interest,  levies,  assessments,  charges,  penalties,  additions to tax or
additional  amounts  imposed by any Taxing  Authority,  (b) any joint or several
liability of such Person with any other Person for

                                       -4-


<PAGE>


the payment of any amounts of the type described in (a) of this definition,  and
(c) any  liability  of such  Person for the  payment of any  amounts of the type
described in (a) as a result of any express or implied  obligation  to indemnify
any other Person.

         Taxing   Authority  shall  mean  any  Authority   responsible  for  the
imposition of any Tax.

         Termination Date shall have the meaning given to it in Section 7.1.

         Tower  Class A  Common  Stock  shall  have the  meaning  given to it in
Section 3.1(c)(i).

         Tower  Class B  Common  Stock  shall  have the  meaning  given to it in
Section 3.1(c)(i).

         Tower  Class C  Common  Stock  shall  have the  meaning  given to it in
Section 3.1(c)(i).

         Tower  Common  Stock  shall  have the  meaning  given to it in  Section
3.1(c)(i).





                                       -5-


                                                                     EXHIBIT 2.4

         FIRST AMENDMENT,  dated as of December 19, 1997 (this "Amendment"),  to
the Amended and Restated Agreement and Plan of Merger,  dated as of December 18,
1997, by and among American Radio Systems  Corporation,  a Delaware  corporation
("American"),  CBS Corporation (formerly,  Westinghouse Electric Corporation), a
Pennsylvania  corporation  ("Mergeparty"),  and R Acquisition  Corp., a Delaware
corporation ("Mergeparty Subsidiary").

                                   WITNESSETH:

         WHEREAS, American,  Mergeparty and Mergeparty Subsidiary are parties to
an Agreement and Plan of Merger,  dated as of September 19, 1997 (the  "Original
Merger Agreement"),  providing for the merger of Mergeparty  Subsidiary with and
into American on the terms and conditions set forth therein; and

         WHEREAS,  American,  Mergeparty and Mergeparty  Subsidiary have entered
into an Amended and Restated Agreement and Plan of Merger,  dated as of December
18, 1997 (the  "Restated  Merger  Agreement"),  to make  certain  changes to the
Original Merger Agreement; and

         WHEREAS, American, Mergeparty and Mergeparty Subsidiary desire to amend
the Restated Merger Agreement.

         NOW,   THEREFORE,   in   consideration   of  the   premises   and   the
representations, warranties, covenants and agreements herein contained and other
valuable   consideration,   the   receipt  and   adequacy   whereof  are  hereby
acknowledged,  the  parties  hereto  hereby,  intending  to  be  legally  bound,
represent, warrant, covenant and agree as follows:

         1.  Capitalized  terms  used  and not  defined  herein  shall  have the
meanings given to such terms in the Restated Merger Agreement.

         2. American hereby represents and warrants to Mergeparty and Mergeparty
Subsidiary as follows,  which  representations and warranties shall be deemed to
form part of the  representations and warranties of American included in Article
Four of the Restated  Merger  Agreement for all purposes of the Restated  Merger
Agreement:  (a)  Annex  1 to  this  Amendment  sets  forth  a  list  of  certain
stockholders  of  American  (the  "Consenting  Stockholders")  and the number of
shares of American Class A Common and American Class B Common owned of record by
each such  stockholder  on the date hereof,  (b) on the date hereof,  29,966,377
votes constituted a majority of the outstanding  voting power of American Common
Stock and (c) on the date  hereof the  Consenting  Stockholders  have  delivered
written  consents  to  American  approving  and  adopting  the  Restated  Merger
Agreement and the Tower Merger  Agreement in  accordance  with  Applicable  Law,
including  without  limitation  the DCL,  such  consents  will,  upon mailing by
American  of the  notice as  described  in  paragraph  3 below,  constitute  the
Required Vote and no other approvals of the  stockholders of American other than
such consents are required to effect either the Merger or the Tower Merger.

         3. American will, promptly after the execution of this Amendment, mail,
in accordance  with Section  228(d) of the DCL,  notice of the corporate  action
without  a  meeting  taken by the  Consenting  Stockholders  to  those  American
stockholders  who have not  consented  to such action in writing and who, if the
action  had been taken at a meeting of  American  stockholders,  would have been
entitled to notice of the  meeting if the record date for such  meeting had been
the date that written consents signed by a sufficient  number of holders to take
such action were delivered to
                                                      
<PAGE>



American in accordance  with Section 228(c) of the DCL. The covenant of American
in this  Section 3 shall be deemed to form  part of the  covenants  of  American
included in Article Six of the Restated Merger Agreement for all purposes of the
Restated Merger Agreement.

         4. All references to "Proxy Statement" in the Restated Merger Agreement
shall be deemed in all cases in the Restated  Merger  Agreement to be references
to "Information  Statement" and all references to "Tower Proxy  Statement" shall
be deemed in all cases in the  Restated  Merger  Agreement to be  references  to
"Tower Information Statement."

         5. Notwithstanding  anything contained in the Restated Merger Agreement
to the contrary,  including  without  limitation  Section 6.5 thereof,  American
shall not be required to hold either the  American  Stockholders  Meeting or the
American Stockholders Tower Meeting.

         6. This  Amendment  shall  constitute  a  Collateral  Document  for all
purposes of the Restated Merger Agreement.

         7. The validity,  interpretation,  construction and performance of this
Amendment shall be governed by, and construed in accordance with, the Applicable
Laws of the  United  States  of  America  and the laws of the  State of New York
applicable  to  contracts  made and  performed  in such State and, in any event,
without  giving effect to any choice or conflict of laws  provision or rule that
would  cause  the  application  of  domestic   substantive  laws  of  any  other
jurisdiction,  except to the extent the corporate  laws of the State of Delaware
are applicable.

         8. This Amendment may be executed in one or more  counterparts,  all of
which shall be considered one and the same agreement, and shall become effective
when one or more  counterparts  have  been  signed  by each of the  parties  and
delivered to the other parties.

         9. Except as  expressly  modified  and amended by this  Amendment,  the
Restated Merger  Agreement shall continue in full force and effect and is hereby
ratified and confirmed in all respects.


                                       -2-

<PAGE>




         IN WITNESS WHEREOF, American, Mergeparty and Mergeparty Subsidiary have
caused this Amendment to be executed,  pursuant to the authority and approval of
each of their respective Boards of Directors, as of the date first written above
by their respective officers thereunto duly authorized.


                              American Radio Systems Corporation


                              By: /s/   Steven B. Dodge
                                  Name:  Steven B. Dodge
                                  Title:  Chairman of the Board,
                                          President and Chief Executive Officer

                              CBS Corporation

                              By: /s/ Frederic G. Reynolds
                                  Name: Frederic G. Reynolds
                                  Title:

                              Acquisition Corp.

                              By: /s/ Frederic G. Reynolds
                                  Name: Frederic G. Reynolds
                                  Title:




                                       -3-





                             AMERICAN TOWER SYSTEMS

FOR IMMEDIATE RELEASE             Contact:  Joe Winn, Chief Financial
                                            Officer or Bruce Danziger, Director
                                            of Investor Relations
                                            Tel:  (617) 375-7500

                             AMERICAN TOWER SYSTEMS
                    TO MERGE WITH AMERICAN TOWER CORPORATION


Boston,  Massachusetts--December  15,  1997--American  Tower Systems Corporation
(ATS), a wholly-owned  subsidiary of American Radio Systems  Corporation  (NYSE:
AFM),  announced  today that it has reached an agreement to merge American Tower
Corporation (ATC) into ATS. American Tower Corporation,  based in Houston,  owns
and/or operates over 750  communications  towers in 32 states,  with significant
regional concentrations in California, Texas and along the Gulf Coast.

ATS will issue in the merger shares of common stock representing 35% of ATS' pro
forma capital  stock to be  outstanding  after giving  effect to the  previously
announced  merger  of  Gearon  and Co.,  Inc.  into ATS and a  proposed  private
placement  of $80.0  million of ATS common  stock,  and to all ATS  existing and
proposed  stock  options.  The  transaction,  which  is  subject  to  regulatory
approval,  is expected to be  consummated in the first half of 1998. ATS will be
the  surviving  corporation  and  will be  renamed  American  Tower  Corporation
effective with the closing.  Fred Lummis,  Chief  Executive  Officer of ATC, and
Randall Mays,  Chief Financial  Officer of Clear Channel  Communications,  Inc.,
will join the Board of Directors of ATS. Clear Channel Communications  currently
owns a 31% interest in ATC.

Steve  Dodge,  CEO of ATS,  stated,  "American  Tower  Corporation  is a rapidly
growing  company  with  terrific  assets,   talented  management  and  a  strong
orientation  to customer  service.  We are delighted to have the  opportunity to
combine their strengths with our own, and we believe that the new American Tower
Corporation will be uniquely positioned to benefit its customers, its people and
ultimately  its  shareholders.  At the  same  time,  we  would  like  to  remind
shareholders  that in the early  going we intend to invest  heavily in  customer
relationships,  new tower development and in the creation of a deep and talented
management team. In doing so, we will be de-emphasizing -- at least initially --
a tidy and predictable quarterly earnings story."

Fred Lummis, CEO of ATC, commented, "American Tower Systems represents the ideal
merger partner for our company  because of its quality  people,  assets and cash
flow.  This  combination  will  provide  a  strategic  platform  from  which  to
participate in the long-term growth of the wireless industry.  We are now poised
to be a leading player in the tower business."

ATS  develops,  acquires,  manages and markets  antenna  sites for the  wireless
communications  industry.  Assuming the closing of all  announced  transactions,
including the ATC merger,  ATS will own and/or manage over 1,750  communications
sites throughout the United States. ATS is headquartered in Boston and maintains
regional offices in Connecticut,  New Jersey,  Pennsylvania,  Washington,  D.C.,
Virginia, South Carolina, Florida, Texas and California.

On September 19, 1997,  American Radio Systems  entered into a merger  agreement
with CBS Corporation pursuant to which its radio operations will become a wholly
owned  subsidiary  of  CBS.  Consummation  of  the  transaction  is  subject  to
regulatory approval.  Around the same time and as a condition of the CBS merger,
American Radio Systems will distribute to its common  shareholders  the stock of
ATS.


                             AMERICAN RADIO SYSTEMS

FOR IMMEDIATE RELEASE             Contact:  Joe Winn, Chief Financial
                                            Officer or Bruce Danziger, Director
                                            of Investor Relations
                                            Tel:  (617) 375-7500

                             AMERICAN TOWER SYSTEMS
                         ACQUIRES GEARON COMMUNICATIONS

Boston,  Massachusetts--December  3,  1997--American  Tower Systems  Corporation
(ATS), a wholly-owned  subsidiary of American Radio Systems  Corporation  (NYSE:
AFM),  announced  today that it has reached an  agreement to merge Gearon & Co.,
Inc.  (Gearon) into ATS. Gearon is an  Atlanta-based  tower site acquisition and
construction  management  company with towers located in the  southeastern  U.S.
Gearon's customers include many of the large cellular and PCS providers.

ATS will pay approximately $32 million in cash and will issue  approximately 5.3
million shares of common stock as consideration for the merger. The transaction,
which is subject to  regulatory  approval,  is expected to close within the next
few weeks.

Steve Dodge, CEO of ATS, stated,  "Michael Gearon has built a highly  profitable
company  with a deep and  capable  staff,  strong  customer  relationships,  and
forward  momentum.  We believe that the partnership of Gearon and American Tower
Systems will provide a very attractive  alternative to various service providers
who may be considering outsourcing their investment in tower infrastructure.  We
will now have the  management  expertise  and the  capital to both  develop  and
finance sites for our customers."

J. Michael Gearon, Jr., who is the principal owner of Gearon and who will become
a Director and Executive Vice President of ATS, commented, "This merger combines
American  Tower's  financial  capabilities,   successful  tower  management  and
ownership experience with Gearon's extensive leadership in turnkey communication
site development. Our new company is now positioned to become the leader in this
emerging industry."

ATS  develops,  acquires,  manages and markets  antenna  sites for the  wireless
communications industry. Assuming the closing of all announced transactions, ATS
will own and/or manage over 1,000  communications  sites  throughout  the United
States.  ATS is  headquartered  in Boston  and  maintains  regional  offices  in
Connecticut,  New  Jersey,  Pennsylvania,   Washington,  D.C.,  Virginia,  South
Carolina, Florida, Texas and
California.

On September 19, 1997,  American Radio Systems  entered into a merger  agreement
with CBS Corporation pursuant to which its radio operations will become a wholly
owned  subsidiary  of  CBS.  Consummation  of  the  transaction  is  subject  to
regulatory  approval.  Around the same time and as a  condition  of the  merger,
American  Radio Systems will  distribute to its  shareholders  the stock of ATS,
which operates its communications tower business.


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                        (617) 375-7500 FAX (617) 375-7575



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