X0303 4/A 2009-08-10 2009-08-12 0000066740 3M CO MMM 0001215821 BUCKLEY GEORGE W 3M CENTER ST. PAUL MN 55144-1000 1 1 CHAIRMAN OF THE BOARD & CEO Common Stock 2009-08-10 4 A 0 5420 70.12 A 267684 D On August 12, 2009, the reporting person reported a grant of an estimated number of restricted stock units with the final number to be determined upon the grant's effective date. The actual number of units was determined on the effective date of the grant (September 1, 2009). This amendment is being filed to update the Form 4 with the actual number of restricted stock units and the value of those units. George Ann Biros, attorney-in-fact for George W. Buckley 2009-09-02