10-K Caterpillar

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

⌧ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2011 OR

TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from Commission File No. 1-768 to .

CATERPILLAR INC.

(Exact name of Registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 100 NE Adams Street, Peoria, Illinois (Address of principal executive offices) Registrant's telephone number, including area code: (309) 675-1000 Securities registered pursuant to Section 12(b) of the Act:

Title of each class Name of each exchange on which registered

37-0602744 (IRS Employer I.D. No.) 61629 (Zip Code)

Common Stock ($1.00 par value)(1) 9 3/8% Debentures due March 15, 2021 8% Debentures due February 15, 2023 5.3% Debentures due September 15, 2035

(1)

New York Stock Exchange New York Stock Exchange New York Stock Exchange New York Stock Exchange

In addition to the New York Stock Exchange, Caterpillar common stock is also listed on stock exchanges in Belgium, France, Germany, Great Britain and Switzerland.

Securities registered pursuant to Section 12(g) of the Act: None Indicate by check mark whether the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ⌧ No Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes No ⌧

Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ⌧ No Indicate by a check mark whether the...