As filed with the Securities and Exchange Commission on February 7, 2002 Registration No. 333- ================================================================================ SECURITIES AND EXCHANGE COMMISSION FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 ----------------- MANTECH INTERNATIONAL CORPORATION (Exact name of registrant as specified in its charter) Delaware 7373 22-1852179 (State or other jurisdiction (Primary Standard Industrial Classification (I.R.S. Employer of incorporation or organization) Code Number) Identification No.) ----------------- ManTech International Corporation 12015 Lee Jackson Highway Fairfax, VA 22033-3300 (703) 218-6000 (Address, including zip code, and telephone number, including area code, of registrant's principal executive offices) ----------------- George J. Pedersen Chairman, Chief Executive Officer and President ManTech International Corporation 12015 Lee Jackson Highway Fairfax, VA 22033-3300 (703) 218-6000 Fax: (703) 218-6301 (Name, address, including zip code, and telephone number, including area code, of agent for service) ----------------- Copies to: John F. Olson Robert G. Robison Ronald O. Mueller Sharon L. Ferko Gibson, Dunn & Crutcher LLP Morgan Lewis & Bockius LLP 1050 Connecticut Avenue, N.W. 101 Park Avenue Washington, D.C. 20036 New York, NY 10178 (202) 955-8500 (212) 309-6000 Fax: (202) 467-0539 Fax: (212) 309-6273 ----------------- Approximate date of commencement of proposed sale to the public: As soon as practicable after this registration statement becomes effective. If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box. [_] If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. [X] 333-73946 If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. [_] If this form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. [_] If delivery of the prospectus is expected to be made pursuant to Rule 434, check the following box. [_] ----------------- CALCULATION OF REGISTRATION FEE ================================================================================ Proposed Maximum Title of each class of Aggregate Amount of securities to be registered Offering Price(1)(2) Registration Fee ---------------------------------------------------------------------------------------- Class A common stock, $0.01 par value per share(3) $22,080,000 $2,031 ================================================================================ (1) Estimated solely for purposes of calculating the registration fee pursuant to Rule 457(o). (2) Includes shares issuable upon exercise of the underwriters' over-allotment option. (3) The $22,080,000 of Class A common stock being registered in this Registration Statement is in addition to the $110,400,000 of Class A common stock registered pursuant to Registrant's Registration Statement on Form S-1 (File No. 333-73946). EXPLANATORY NOTE This Registration Statement is being filed pursuant to Rule 462(b) under the Securities Act of 1933, as amended. The contents of the Registration Statement on Form S-1 (File No. 333-73946) filed by ManTech International Corporation with the Securities and Exchange Commission (the "Commission") on November 23, 2001, as amended, which was declared effective by the Commission on February 6, 2002, and including the documents filed by the Company with the Commission and incorporated or deemed to be incorporated therein, are incorporated herein by reference. 1 SIGNATURES Pursuant to the requirements of the Securities Act of 1933, the registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Washington, D.C., on February 7, 2002. MANTECH INTERNATIONAL CORPORATION By: /s/ GEORGE J. PEDERSEN --------------------- George J. Pedersen Chairman of the Board of Directors, Chief Executive Officer and President Pursuant to the requirements of the Securities Act of 1933, as amended, this registration statement has been signed by the following persons in the capacities indicated on February 7, 2002. Signature Title --------- ----- /s/ GEORGE J. PEDERSEN Chairman of the Board of Directors, Chief Executive Officer ---------------------- and President /s/ JOHN A. MOORE, JR. Executive Vice President, Chief Financial Officer, Treasurer ---------------------- and Director /s/ MICHAEL D. GOLDEN ---------------------- Director /s/ STEPHEN W. PORTER ---------------------- Director /s/ WALTER W. VAUGHAN ---------------------- Director EXHIBIT INDEX Exhibit Number Description of Exhibit ------ ---------------------- 5.1 Opinion of Gibson, Dunn & Crutcher LLP 23.1 Consent of Deloitte & Touche LLP 23.2 Consent of PricewaterhouseCoopers LLP