Singapore stocks finished down on Tuesday, with the benchmark Straits Times Index down 2.22 points, or 0.07 percent, to close at 3,103.62. A total of 2.1 billion shares changed hands with turnover of 1. 02 billion Singapore dollars (809 million U.S. dollars). Losers led gainers 221 to 202, while 521 others finished unchanged. The STI index gains 5.91 points, or 0.19 percent, to close at 3, 105.84 on Monday.