AMERICAN TOWER CORP /MA/ — Director's Dealing 2011

Nov 9, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AMERICAN TOWER CORP /MA/ (AMT)
CIK: 0001053507
Period of Report: 2011-11-07

Reporting Person: DiSanto Edmund (EVP, Chief Admin Officer & GC)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-11-07	Class A Common Stock	M	25543	$28.39	Acquired	52963	Direct
2011-11-07	Class A Common Stock	S	25543	$58.40	Disposed	27420	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2011-11-07	Option to Purchase Class A Common Stock	$28.39	M	25543	Disposed	2019-03-10	Class A Common Stock (25543)	Direct

Footnotes

F1: Includes 128 shares acquired under the Company's employee stock purchase plan in May 2011.

F2: The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan.

F3: This option was granted pursuant to the 2007 Equity Incentive Plan and is exercisable in 25% cumulative annual increments beginning March 10, 2010.