Registration No. 333-47381 ================================================================================ SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Post-Effective Amendment No. 1 to FORM S-4 REGISTRATION STATEMENT Under THE SECURITIES ACT OF 1933 FIRST MIDWEST BANCORP, INC. (Exact name of registrant as specified in its charter) 6022 (Primary Standard Industrial Classification Code Number) Delaware 36-3161078 (State or other jurisdiction (I.R.S. Employer of incorporation or organization) Identification No.) 300 Park Boulevard, Suite 405, Itasca, Illinois 60143-0459, (630) 875-7450 (Address, including zip code, and telephone number, including area code, of registrant's principal executive offices) Donald J. Swistowicz Executive Vice President First Midwest Bancorp, Inc. 300 Park Boulevard, Suite 405, Itasca, Illinois 60143-0459 (630) 875-7460 (Name, address, including zip code, and telephone number, including area code, of agent for service) Copies to: Timothy M. Sullivan John E. Freechack Joel S. Corwin Hinshaw & Culbertson Barack Ferrazzano Kirschbaum Perlman & Nagelberg Law Offices of Joel S. Corwin 222 North LaSalle Street 333 West Wacker Drive 20 South Clark Street Suite 300 Suite 2700 Suite 2200 Chicago, Illinois 60601-1081 Chicago, Illinois 60606 Chicago, Illinois 60603 (312) 704-3852 (312) 984-3100 (312) 357-0100 Approximate date of commencement of proposed sale of the securities to the public: Upon consummation of the Merger as described in the Registration Statement. If the only securities being registered on this form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box: [_] The registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the Registration Statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine. Pursuant to this Registration Statement on Form S-4 (No. 333-47381), First Midwest Bancorp, Inc. ("First Midwest"), registered 9,719,657 shares of its common stock, $.01 par value per share ("Common Stock"), issuable pursuant to an Agreement and Plan of Merger dated as of January 14, 1998 by and among First Midwest, First Midwest Acquisition Corporation ("Acquisition Corp."), a wholly owned subsidiary of First Midwest, and Heritage Financial Services, Inc. ("Heritage"), which provided for the merger of Heritage into Acquisition Corp. (the "Merger"). On July 1, 1998, First Midwest consummated the Merger whereby each outstanding share of Heritage's common stock, no par value, was converted into, and became exchangeable for .7695 shares of First Midwest Common Stock, resulting in the issuance of an aggregate of 9,628,050 shares of First Midwest Common Stock. First Midwest hereby amends this Registration Statement to deregister 91,607 shares of Common Stock that remain unissued following the consummation of the Merger. SIGNATURES Pursuant to the requirements of the Securities Act of 1933, as amended, First Midwest Bancorp, Inc., has duly caused this Post-Effective Amendment No. 1 to the Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the Village of Itasca, State of Illinois, this 21st day of August,1998. FIRST MIDWEST BANCORP, INC. By: /s/ Robert P. O'Meara ------------------------------------------------- Robert P. O'Meara Chairman of the Board and Chief Executive Officer Signature Capacity - ------------------------------ ------------------------------------------------- /s/ Robert P. O'Meara - ------------------------------ Robert P. O'Meara Chairman of the Board and Chief Executive Officer * - ------------------------------ Andrew B. Barber Honorary Chairman of the Board of Directors * - ------------------------------ John M. O'Meara President, Chief Operating Officer and Director /s/ Donald J. Swistowicz - ------------------------------ Donald J. Swistowicz Executive Vice President, Chief Financial and Accounting Officer * - ---------------------------------------- Vernon A. Brunner Director * - ---------------------------------------- Bruce S. Chelberg Director * - ---------------------------------------- William J. Cowlin Director * - ---------------------------------------- O. Ralph Edwards Director * - ---------------------------------------- Joseph W. England Director * - ---------------------------------------- Brother James Gaffney, F.S.C. Director * - ---------------------------------------- Thomas M. Garvin Director * - ---------------------------------------- Jack Payan Director * - ---------------------------------------- John L. Sterling Director * - ---------------------------------------- J. Stephen Vanderwoude Director * - ---------------------------------------- Richard T. Wojcik Director * By Robert P. O'Meara and Donald J. Swistowicz, as attorneys-in-fact