SINGAPORE, May 24 (AFP) - The Singapore dollar, Thai baht and the Indonesian rupiah weakened Monday against the dollar even as the yen held steady despite its bearish prospects, dealers said. The Singapore dollar fell to 1.7226 against the greenback from 1.7198 on Friday and the Thai baht to 37.08 from 37.00 and the rupiah to 8,075 from 8,045. "The Singapore dollar was trapped in a range of 1.7204 to 1.7241," said Alison Seng, analyst with Standard and Poor's MMS in Singapore. The baht, she said, traded between 37.08 and 37.18, little affected by a cut in lending rates by a top commercial bank which usually sets the pace for such reductions. "This implies that the stance of the Thai central bank has not changed and the trend continues for easier monetary policy for 1999 despite the likelihood about rates going up in the US," Seng said. The yen maintained around the 124 level for most of the day despite reports that it could slip to as low as 140, Seng said. "It did not budge, probably due to the holiday in most European markets today," she said. The yen closed Asian trading at 123.93 from the New York closing of 124.03 on Friday.  