UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                                (Amendment No. )*

                           American Tower Corporation
                                (Name of Issuer)

                      Class A Common Stock, $.01 par value
                         (Title of Class of Securities)

                                    029912201
                                 (CUSIP Number)

                                  June 4, 1998
             (Date of Event which Requires Filing of this Statement)

Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:


     [ ]  Rule 13d-1(b)

     [ ]  Rule 13d-(c)

     [X]  Rule 13d-1(d)





















- --------------------
* The remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for any  subsequent  amendment  containing  information  which  would  alter the
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).


CUSIP No. 029912201 13G Page 2 of 5 Pages - ------------------- ----------------- 1 Name of Reporting Person/I.R.S. Identification Nos. of Above Persons (Entities Only) J. Michael Gearon, Jr. 2 Check the Appropriate Box If a Member of a Group (a) |_| (See Instructions) (b) |_| 3 SEC Use Only 4 Citizenship or Place of Organization United States of America 5 Sole Voting Power Number of Shares 4,021,328 Beneficially 6 Shared Voting Power Owned by Each -0- Reporting 7 Sole Dispositive Power Person With 4,021,328 8 Shared Dispositive Power -0- 9 Aggregate Amount Beneficially Owned by Each Reporting Person 4,021,328 10 Check If the Aggregate Amount in Row (9) Excludes Certain Shares |X| (See Instructions) 11 Percent of Class Represented by Amount in Row (9) 4.2% 12 Type of Reporting Person (See Instructions) IN - ---------- ---------------

CUSIP No. 029912201 13G Page 3 of 5 Pages - ------------------- ----------------- Item 1(a). Name of issuer: American Tower Corporation Item 1(b). Address of Issuer's Principal Executive Offices: 116 Huntington Avenue, Boston, Massachusetts 02116 Item 2(a). Name of Person Filing: J. Michael Gearon, Jr. Item 2(b). Address of Principal Offices or, if None, Residence: 2995 Paces Lakes Court, Atlanta, Georgia 30339 Item 2(c). Citizenship: United States of America Item 2(d). Title of Class of Securities: Class A Common Stock, $.01 par value Item 2(e). CUSIP Number: 029912201 Item 3. If the Statement is being filed pursuant to Rule 13d-1(b) or 13d-2(b) or (c), check whether the filing person is a: (a) [ ] Broker or dealer registered under section 15 of the Act. (b) [ ] Bank as defined in section 3(a)(6) of the Act. (c) [ ] Insurance company as defined in section 3(a)(19) of the Act. (d) [ ] Investment company registered under section 8 of the Investment Company Act of 1940. (e) [ ] An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E); (f) [ ] An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F); (g) [ ] A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G); (h) [ ] A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act; (i) [ ] A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act; (j) [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(J). If this statement is filed pursuant to Rule 13d-1(c), check this box. [ ]

CUSIP No. 029912201 13G Page 4 of 5 Pages - ------------------- ----------------- Item 4. Ownership. The holdings reported herein are stated as of December 31, 1998. Mr. Gearon acquired 4,711,113 shares of Class A Common Stock of American Tower Systems Corporation (now known as American Tower Corporation, "ATC"), pursuant to the merger of Gearon & Co., Inc. with and into a subsidiary of ATC, effective on January 22, 1998. Mr. Gearon became the beneficial owner of more than 5% of the issuer's Class A Common Stock as a result of the separation (the "ATC Separation") of ATC from American Radio Systems Corporation ("American Radio"), pursuant to the merger of American Radio with and into a subsidiary of CBS Corporation, effective June 4, 1998 and the filing of a Form 8-A by ATC on June 4, 1998. (a) Amount beneficially owned: 4,021,328 shares (b) Percent of class: 4.2% (c) Number of shares as to which such person has: (i) Sole power to vote or direct the vote: 4,021,328 shares (ii) Shared power to vote or direct the vote: -0- (iii) Sole power to dispose or to direct the disposition of: 4,021,328 shares (iv) Shared power to dispose or to direct the disposition of: -0- Item 5. Ownership of Five Percent or Less of a Class. If this statement is being filed to report the fact that as of the date hereof the reporting person had ceased to be the beneficial owner of more than five percent of the class of securities, check the following [ X ]. Item 6. Ownership of More than Five Percent on Behalf of Another Person. The shares identified in Item 4 include the following shares owned beneficially: 3,974,437 shares of Class A Common Stock currently owned by Mr. Gearon. Does not include 400,000 shares of Class A Common Stock held by a trust for the benefit of Mr. Gearon's children of which J. Michael Gearon, Sr. is the trustee. Mr. Gearon disclaims beneficial ownership in all shares owned by such trust. Does not include 187,560 shares of Class A Common Stock purchasable under an option granted on January 22, 1998 under the ATC 1997 Stock Option Plan (the "Plan") and 100,000 shares of Class A Common Stock purchasable under an option granted on December 1, 1998 under the Plan; includes 46,891 shares as to which the January option is exercisable. Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company. Not applicable. Item 8. Identification and Classification of Members of the Group. Not applicable. Item 9. Notice of Dissolution of Group. Not applicable. Item 10. Certification. Not applicable.

CUSIP No. 029912201 13G Page 5 of 5 Pages - ------------------- ----------------- SIGNATURE After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. February 16, 1999 (Date) /s/ J. Michael Gearon, Jr. (Signature) J. Michael Gearon, Jr. (Name/Title) Attention. Intentional misstatements or omissions of fact constitute Federal criminal violations (See 18 U.S.C. 1001)