UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-A/A

(Amendment No. 1)

FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES

PURSUANT TO SECTION 12(b) OR 12(g) OF THE

SECURITIES EXCHANGE ACT OF 1934

Securities to be registered pursuant to Section 12(b) of the Act:

If this form relates to the registration of a class of securities pursuant to Section 12(b) of the Exchange Act and is effective pursuant to General Instruction A.(c), check the following box.   ¨

If this form relates to the registration of a class of securities pursuant to Section 12(g) of the Exchange Act and is effective pursuant to General Instruction A.(d), check the following box.   ¨

Securities Act registration statement file number to which this form relates: N/A.

Securities to be registered pursuant to Section 12(g) of the Act: None.

Item 1. Description of Registrant’s Securities to be Registered.

This Form 8-A/A amends the Form 8-A filed on March 9, 2011 (the “Original 8-A”) by American International Group, Inc. (“AIG”) relating to stock purchase rights (the “Rights”) previously dividended to AIG’s shareholders as part of AIG’s Tax Asset Protection Plan, dated as of March 9, 2011 (the “Plan”), between AIG and Wells Fargo Bank, National Association, as Rights Agent (the “Rights Agent”). The Plan, the purpose of which is to help protect AIG’s ability to recognize certain tax benefits in future periods from net operating losses and other tax attributes, was originally entered into on March 9, 2011, and was originally scheduled to expire at the close of business on March 9, 2014 (subject to other earlier termination events as described in the Plan). On January 8, 2014, AIG and the Rights Agent entered into Amendment No. 1 to the Plan, which extends the expiration date of the Plan to January 8, 2017 (subject to other earlier termination events as described in the Plan) and also makes minor technical changes to the Plan.

The Plan is described in and included as Exhibit 4.1 to AIG’s Current Report on Form 8-K, dated March 9, 2011. The foregoing description of Amendment No. 1 to the Plan is qualified in its entirety by reference to the full text of Amendment No. 1 to the Plan, which is included as Exhibit 4.1 to AIG’s Current Report on Form 8-K, dated January 8, 2014, and incorporated in its entirety into this Item 1 by reference.

SIGNATURE

Pursuant to the requirements of Section 12 of the Securities Exchange Act of 1934, the registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereto duly authorized.