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

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AMERICAN TOWER CORP /MA/ (AMT)
CIK: 0001053507
Period of Report: 2011-12-05

Reporting Person: DOLAN RAYMOND P (Director)

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-12-05	Class A Common Stock	M	25000	$4.80	Acquired	31313	Direct
2011-12-05	Class A Common Stock	M	10000	$12.11	Acquired	41313	Direct
2011-12-05	Class A Common Stock	S	35000	$59.36	Disposed	6313	Direct
2011-12-06	Class A Common Stock	M	10000	$18.15	Acquired	16313	Direct
2011-12-06	Class A Common Stock	S	10000	$59.05	Disposed	6313	Direct

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2011-12-05	Option to Purchase Class A Common Stock	$4.80	M	25000	Disposed	2013-02-27	Class A Common Stock (25000)	Direct
2011-12-05	Option to Purchase Class A Common Stock	$12.11	M	10000	Disposed	2014-03-04	Class A Common Stock (10000)	Direct
2011-12-06	Option to Purchase Class A Common Stock	$18.15	M	10000	Disposed	2015-04-01	Class A Common Stock (10000)	Direct

F1: The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan.

F2: Represents the weighted average price of shares sold in multiple same-day transactions at prices ranging from $59.21 to $59.63 per share.

F3: This option was granted pursuant to the 1997 Stock Option Plan, as amended, and was fully vested on February 27, 2003.

F4: This option was granted pursuant to the 1997 Stock Option Plan, as amended, and was fully vested on March 4, 2004.

F5: This option was granted pursuant to the 1997 Stock Option Plan, as amended, and was fully vested on April 1, 2005.