AMERICAN TOWER CORP /MA/ — Director's Dealing 2012

Jul 2, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AMERICAN TOWER CORP /MA/ (AMT)
CIK: 0001053507
Period of Report: 2012-06-29

Reporting Person: Marshall Steven C. (EVP & President, U.S. Tower)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-06-29	Common Stock	M	51488	$28.39	Acquired	54898	Direct
2012-06-29	Common Stock	S	51488	$70.13	Disposed	3410	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-06-29	Option to Purchase Common Stock	$28.39	M	51488	Disposed	2019-03-10	Common Stock (51488)	Direct

Footnotes

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

F2: This option was granted pursuant to the 2007 Equity Incentive Plan, and vests in 25% cumulative annual increments beginning March 10, 2010.