The benchmark index of the Indian equities market closed lower on Monday with the 30-scrip sensitive index of the Bombay Stock Exchange, Sensex, closing at 18307.52 points, 290.66 points or 1.56 percent lower from the previous close of 18598.18 points. The Sensex had a turnover of 5.75 billion rupees (about 92.76 million U.S. dollars).