WASHINGTON (AP) _ CoStar Group Inc. (CSGP) on Tuesday reported first-quarter earnings of $89.3 million.The Washington-based company said it had profit of 23 cents per share. Earnings, adjusted for one-time gains and costs, came to 31 cents per share. The results surpassed Wall Street expectations. The average estimate of four analysts surveyed by Zacks Investment Research was for earnings of 28 cents per share. The commercial real estate information and marketing provider posted revenue of $515.8 million in the period, also beating Street forecasts.