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

Mar 14, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AMERICAN TOWER CORP /MA/ (AMT)
CIK: 0001053507
Period of Report: 2011-03-10

Reporting Person: Kearns Mark (VP Int'l Finance & Treasurer)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2011-03-10	Option to Purchase Class A Common Stock	$50.78	A	11690	Acquired	2021-03-10	Class A Common Stock (11690)	Direct
2011-03-10	Restricted Stock Units	$	A	3939	Acquired		Class A Common Stock (3939)	Direct

Footnotes

F1: This option was granted pursuant to the 2007 Equity Incentive Plan, and is exercisable in 25% cumulative annual increments beginning March 10, 2012.

F2: Each Restricted Stock Unit (RSU) respresents a contingent right to receive one share of Class A Common Stock.

F3: This RSU was granted pursuant to the 2007 Equity Incentive Plan, and vests in 25% cumulative annual increments beginning March 10, 2012.