MIDEAST STOCKS-Dubai's index closes 1.8 pct lower after weak Q1 earnings

(Updates with Dubai closed) DUBAI, May 11 (Reuters) - Dubai's stock index fell on Monday after some local companies posted disappointing first-quarter earnings. The emirate's benchmark closed 1.8 percent lower and developer Union Properties tumbled its daily 10 percent limit after saying its first-quarter profit had fallen to 28.1 million dirhams ($7.7 million) from 179.8 million dirhams a year earlier. Low-cost carrier Air Arabia fell 1.3 percent after posting a 9 percent year-on-year increase