Form of Underwriting Agreement 1,250,000 Shares* COSTAR GROUP, INC. Common Stock UNDERWRITING AGREEMENTUnderwriting Agreement • October 10th, 2003 • Costar Group Inc • Services-business services, nec • New York
CoStar Group, Inc., a Delaware corporation (the “Company”), proposes to issue and sell 1,250,000 shares (the “Firm Shares”) of the Company’s Common Stock, $.01 par value (the “Common Stock”), to you and to the several other Underwriters named in Schedule I hereto (collectively, the “Underwriters”), for whom you are acting as representatives (the “Representatives”). The Company has also agreed to grant to you and the other Underwriters an option (the “Option”) to purchase up to an additional 187,500 shares of Common Stock, on the terms and for the purposes set forth in Section 1(b) (the “Option Shares”). The Firm Shares and the Option Shares are referred to collectively herein as the “Shares.”
