PRESS RELEASE DETAIL


Jan 18, 2008

CoStar Group Underwriters Exercise Full Over-Allotment Shares

2003-11-24 2003 CoStar Group Underwriters Exercise Full Over-Allotment Shares

BETHESDA, MD -- CoStar Group, Inc. (NASDAQ: CSGP), the leading provider ...

2003-11-24 2003 CoStar Group Underwriters Exercise Full Over-Allotment Shares

BETHESDA, MD -- CoStar Group, Inc. (NASDAQ: CSGP), the leading provider of information services to commercial real estate professionals in the United States and the United Kingdom, announced that the underwriters for its follow-on public stock offering exercised the full over-allotment option to purchase an additional 217,500 shares from the Company at a price of $34.25 per share. CoStar Group's total net proceeds from the offering and the over-allotment option were approximately $53.6 million after deducting offering expenses.

The offering was underwritten by Needham & Company, Inc., William Blair & Co. and JMP Securities LLC.

A copy of the prospectus can be obtained from Needham & Company, Inc., 445 Park Avenue, New York, NY 10022; William Blair & Co., 222 West Adams Street, Chicago, IL 60606; or JMP Securities LLC, One Embarcadero Center, Suite 2100, San Francisco, CA 94111.

This news release includes "forward-looking statements" including, without limitation, statements regarding CoStar's expectations, beliefs, intentions or strategies regarding the future. These statements are subject to many risks and uncertainties that could cause actual results to differ materially from these statements. More information about potential factors that could cause actual results to differ materially include, but are not limited to, those stated in CoStar's filings from time to time with the Securities and Exchange Commission, including CoStar's Form 10-Q for the quarter ended September 30, 2003, under the heading "Risk Factors". All forward-looking statements are based on information available to CoStar on the date hereof, and CoStar assumes no obligation to update such statements.
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