GATX CORP — Director's Dealing 2007

May 22, 2007

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: GATX CORP (GMT)
CIK: 0000040211
Period of Report: 2007-05-21

Reporting Person: Porzenheim Clifford J (N/A)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2007-05-21	Common Stock	M	4500	$39.7188	Acquired	19136.3444	Direct
2007-05-21	Common Stock	M	5000	$39.4688	Acquired	24136.3444	Direct
2007-05-21	Common Stock	M	8000	$30.4688	Acquired	32136.3444	Direct
2007-05-21	Common Stock	S	17500	$51	Disposed	14636.3444	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2007-05-21	1998 NQ Stock Option (Right to Buy)	$39.7188	M	4500	Disposed	2008-07-24	Common Stock (4500)	Direct
2007-05-21	1999 NQ Stock Option (Right to Buy)	$39.4688	M	5000	Disposed	2009-07-23	Common Stock (5000)	Direct
2007-05-21	2000 NQ Stock Option (Right to Buy)	$30.4688	M	8000	Disposed	2010-03-10	Common Stock (8000)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock 401(k)	7349.721	Indirect

Footnotes

F1: GATX Corporation's 401(k) plan is a unitized stock fund made up of company stock plus short term investments. Because the fund includes more than company stock, participants purchase units of the fund rather than company shares of stock. The number of units held by a participant may vary depending on the performance of the company stock, the overall stock market, and the amount of short term investments in the fund. Such a variance has caused the value of the units in the reporting person's 401(k) fund to be reduced without any actual disposition of shares.

F2: 50% of option granted may be exercised commencing 1 year from the date of the grant, an additional 25% commencing 2 years from the date of the grant and the remaining 25% commencing 3 years from the date of the grant.

F3: 50% of option granted may be exercised commencing 1 year from the date of the grant, an additional 25% commencing 2 years from the date of the grant and the remaining 25% commencing 3 years from the date of the grant.

F4: 50% of option granted may be exercised commencing 1 year from the date of the grant, an additional 25% commencing 2 years from the date of the grant and the remaining 25% commencing 3 years from the date of the grant.