Form 13G/A
United States
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
Under the Securities Exchange Act of 1934
(Amendment No. 1)*
Name of Issuer - American Tower Corp.
Title or Class of Securities - Common Stock
CUSIP Number - 029912201
Check the following box if a fee is being paid with this
statement [ ].
Cusip No. 029912201
Page 2 of 6 Pages
1. Name of Reporting Person (S.S. or I.R.S. Identification No. of above
person)
American Century Investment Management, Inc. - 44-0640487
2. Check the appropriate box if a member of a group* - N/A
3. SEC Use Only
4. Citizenship or place of organization
Delaware
5. Sole voting power
N/A
6. Shared voting power
N/A
7. Sole dispositive power
N/A
8. Shared dispositive power
N/A
9. Aggregate amount beneficially owned by each reporting person
N/A
10. Check box if the aggregate amount in Row (9) excludes certain shares
N/A
11. Percent of class represented by amount in Row 9
N/A
12. Type of reporting person*
IA
Cusip No. 029912201
Page 3 of 6 Pages
1. Name of Reporting Person (S.S. or I.R.S. Identification No. of above
person)
American Century Mutual Funds, Inc. - 44-6006315
2. Check the appropriate box if a member of a group* - N/A
3. SEC Use Only
4. Citizenship or place of organization
Maryland
5. Sole voting power
N/A
6. Shared voting power
N/A
7. Sole dispositive power
N/A
8. Shared dispositive power
N/A
9. Aggregate amount beneficially owned by each reporting person
N/A
10. Check box if the aggregate amount in Row (9) excludes certain shares
N/A
11. Percent of class represented by amount in Row 9
N/A
12. Type of reporting person*
IV
SCHEDULE 13G
Item 1(a). NAME OF ISSUER
American Tower Corp.
Item 1(b). ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES
116 Huntington Avenue
Boston, MA 02116-5749
Item 2(a). NAME OF PERSONS FILING
American Century Investment Management, Inc. on its behalf and on behalf
of:
American Century Mutual Funds, Inc. - 44-6006315
Item 2(b). ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE
4500 Main Street
P.O. Box 418210
Kansas City, MO 64141-9210
Attn: Charles C.S. Park
Item 2(c). CITIZENSHIP
Delaware
Item 2(d). TITLE OF CLASS OF SECURITIES
Common Stock
Item 2(e). CUSIP NO.
029912201
Item 3. IF THIS STATEMENT IS FILED PURSUANT TO RULES 13d-1(b) OR 13d-2(b),
CHECK WHETHER THE PERSON FILING IS A
(g) [ X ] Registered Investment Adviser, in accordance with
Rule 13d-1(b)(ii)(E) (Note: See Item 7).
Item 4. OWNERSHIP
(a) Aggregate amount beneficially owned:
N/A
(b) Percent of class:
N/A
(c) Number of shares as to which such person has:
(i) sole power to vote or to direct the vote:
N/A
(ii) shared power to vote or to direct the vote:
N/A
(iii)sole power to dispose or to direct the disposition of:
N/A
(iv) shared power to dispose or to direct the disposition of:
N/A
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 has 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
American Century Investment Management, Inc. ("ACIM"), a registered
investment adviser, manages, pursuant to management agreements, the investments
of fourteen registered investment companies, American Century Mutual Funds,
Inc., American Century World Mutual Funds, Inc., American Century Capital
Portfolios, Inc., American Century Variable Portfolios, Inc., American Century
Variable Portfolios II, Inc., American Century Premium Reserves, Inc., American
Century Strategic Asset Allocations, Inc., American Century Municipal Trust,
American Century Quantitative Equity Funds, Inc., American Century International
Bond Funds, Inc., American Century Investment Trust, American Century Government
Income Trust, American Century Target Maturities Trust, and American Century
California Tax-Free and Municipal Funds, Inc., and manages, pursuant to
sub-advisory agreements, the investments of eight registered investment
companies, American Skandia Trust, American Skandia Advisor Funds, Inc., Style
Select Series, Inc., Mainstay VP Series Fund, Inc., Principal Investors Fund,
Inc., North American Funds Variable Product Series I, Season Series Trust and
AXP Partners International Series, Inc. ACIM also manages the assets of
institutional investor accounts. The securities that are the subject of this
report are owned by and held for such investment companies and separate
institutional investor accounts. Any dividends received from such securities, or
the proceeds of any sale of such securities, are for the benefit of, and are
held for such investment companies and separate institutional investor accounts.
Item 7. IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE
SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY
N/A
Item 8. IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP
N/A
Item 9. NOTICE OF DISSOLUTION OF GROUP
N/A
Item 10. CERTIFICATION
By signing below I certify that, to the best of my knowledge and belief,
the securities referred to above were acquired in the ordinary course of
business and were not acquired for the purpose of and do not have the effect of
changing or influencing the control of the issuer of such securities and were
not acquired in connection with or as a participant in any transaction having
such purpose or effect.
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 8, 2002 AMERICAN CENTURY INVESTMENT MANAGEMENT, INC.
Date
By: /s/Charles C.S. Park
Charles C.S. Park
Assistant General Counsel
EXHIBIT A
Rule 13d-1(f)(1)(iii) Agreement
Each of the undersigned hereby agrees and consents to the execution and
joint filing on its behalf by American Century Investment Management, Inc. of
this Schedule 13G respecting the beneficial ownership of the securities which
are the subject of this schedule at December 31, 2001.
Dated this 8th day of February, 2002.
American Century Investment Management, Inc.
By: /s/Charles C.S. Park
Charles C.S. Park
Assistant General Counsel
American Century Mutual Funds, Inc.
By: /s/Charles C.S. Park
Charles C.S. Park
Vice President