GATX CORP — Director's Dealing 2007

May 2, 2007

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: GATX CORP (GMT)
CIK: 0000040211
Period of Report: 2007-04-30

Reporting Person: MUCKIAN WILLIAM M (N/A)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2007-04-30	Common Stock	M	2750	$39.7188	Acquired	10158	Direct
2007-04-30	Common Stock	M	3000	$39.4688	Acquired	13158	Direct
2007-04-30	Common Stock	S	5750	$49.9064	Disposed	7408	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2007-04-30	1998 NQ Stock Option (Right to Buy)	$39.7188	M	2750	Disposed	2008-07-24	Common Stock (2750)	Direct
2007-04-30	1999 NQ Stock Option (Right to Buy)	$39.4688	M	3000	Disposed	2009-07-23	Common Stock (3000)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock 401(k)	4632.377	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.