UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): January 18, 2011

STERLING BANCSHARES, INC.

(Exact name of registrant as specified in its charter)

2950 North Loop West, Suite 1200

Houston, Texas 77092

(Address of principal executive offices) (Zip Code)

(713) 466-8300

(Registrant’s telephone number, including area code)

10260 Westheimer

Houston, Texas 77042

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

On January 18, 2011, Sterling Bancshares, Inc., a Texas corporation (“Sterling”) and Comerica Incorporated, a Delaware corporation (“Comerica”), announced that they had entered into an Agreement and Plan of Merger (the “Merger Agreement”), providing for, among other things, the acquisition by Comerica of all outstanding shares of common stock of Sterling in a stock-for-stock transaction. Under the terms of the Merger Agreement, a wholly-owned subsidiary of Comerica will merge with Sterling (the “Merger”), and existing shareholders of Sterling will become entitled to receive common shares of Comerica. The Merger is subject to customary closing conditions, including regulatory approvals and approval from the shareholders of Sterling. A copy of the news release announcing the Merger Agreement is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

(d) Exhibits:

FORWARD-LOOKING STATEMENTS

Any statements in this filing that are not historical facts are forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995. Words such as “anticipates,” “believes,” “feels,” “expects,” “estimates,” “seeks,” “strives,” “plans,” “intends,” “outlook,” “forecast,” “position,” “target,” “mission,” “assume,” “achievable,” “potential,” “strategy,” “goal,” “aspiration,” “outcome,” “continue,” “remain,” “maintain,” “trend,” “objective” and variations of such words and similar expressions, or future or conditional verbs such as “will,” “would,” “should,” “could,” “might,” “can,” “may” or similar expressions, as they relate to Comerica, Sterling, the proposed transaction or the combined company following the transaction often identify forward-looking statements. These forward-looking statements are predicated on the beliefs and assumptions of management based on information known to management as of the date of this presentation and do not purport to speak as of any other date. Forward-looking statements may include descriptions of the expected benefits and costs of the transaction; forecasts of revenue, earnings or other measures of economic performance, including statements of profitability, business segments and subsidiaries; management plans relating to the transaction; the expected timing of the completion of the transaction; the ability to complete the transaction; the ability to obtain any required regulatory, shareholder or other approvals; any statements of the plans and objectives of management for future or past operations, products or services, including the execution of integration plans; any statements of expectation or belief; and any statements of assumptions underlying any of the foregoing. Such statements reflect the view of management as of this date with respect to future events and are subject to risks and uncertainties. Should one or more of these risks materialize or should underlying beliefs or assumptions prove incorrect, actual results could differ materially from those anticipated by the forward-looking statements or historical results. Factors that could cause or contribute to such differences include, but are not limited to, the possibility that expected benefits may not materialize in the timeframe expected or at all, or may be more costly to achieve; that the transaction may not be timely completed, if at all; that prior to the completion of the transaction or thereafter, Comerica’s and Sterling’s

respective businesses may not perform as expected due to transaction-related uncertainty or other factors; that the parties are unable to successfully implement integration strategies; that required regulatory, shareholder or other approvals are not obtained or other closing conditions are not satisfied in a timely manner or at all; reputational risks and the reaction of the companies’ customers to the transaction; diversion of management time on merger-related issues; and those factors referenced in Comerica’s and Sterling’s filings with the Securities and Exchange Commission (the “SEC”). Forward-looking statements speak only as of the date they are made. Comerica and Sterling do not undertake to update forward-looking statements to reflect facts, circumstances, assumptions or events that occur after the date the forward-looking statements are made. For any forward-looking statements made in this document or in any other documents, Comerica and Sterling claim the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995.

ADDITIONAL INFORMATION FOR SHAREHOLDERS

In connection with the proposed merger transaction, Comerica will file with the SEC a Registration Statement on Form S-4 that will include a Proxy Statement of Sterling, and a Prospectus of Comerica, as well as other relevant documents concerning the proposed transaction. SHAREHOLDERS ARE URGED TO READ THE REGISTRATION STATEMENT AND THE PROXY STATEMENT/PROSPECTUS REGARDING THE MERGER WHEN IT BECOMES AVAILABLE AND ANY OTHER RELEVANT DOCUMENTS FILED WITH THE SEC, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THOSE DOCUMENTS, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION.

A free copy of the Proxy Statement/Prospectus, as well as other filings containing information about Comerica and Sterling, may be obtained at the SEC’s Internet site (http://www.sec.gov). You will also be able to obtain these documents, free of charge, from Comerica at www.comerica.com under the tab “Investor Relations” and then under the heading “SEC Filings” or from Sterling by accessing Sterling’s website at www.banksterling.com under the tab “Investor Relations” and then under the heading “SEC Filings.”

Comerica and Sterling and certain of their directors and executive officers may be deemed to be participants in the solicitation of proxies from the shareholders of Sterling in connection with the proposed merger. Information about the directors and executive officers of Comerica is set forth in the proxy statement for Comerica’s 2010 annual meeting of shareholders, as filed with the SEC on a Schedule 14A on March 19, 2010. Information about the directors and executive officers of Sterling is set forth in the proxy statement for Sterling’s 2010 annual meeting of shareholders, as filed with the SEC on a Schedule 14A on March 5, 2010 and on Forms 8-K filed with the SEC on June 25, 2010 and July 12, 2010. Additional information regarding the interests of those participants and other persons who may be deemed participants in the transaction may be obtained by reading the Proxy Statement/Prospectus regarding the proposed merger when it becomes available. Free copies of this document may be obtained as described in the preceding paragraph.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned authorized officer.

EXHIBIT INDEX