Thai share prices fell 1.60 percent on Wednesday following the central bank's decision to raise its benchmark interest rate by a larger-than-expected half point, dealers said.
The Bank of Thailand raised its benchmark interest rates by a larger than expected half a point to 3.75 percent in a bid to tame rising inflation driven by soaring oil prices.
The Stock Exchange of Thailand (SET) composite index plunged 11.11 points to 684.07 and the blue chip SET 50 index dropped 9.17 points to 478.10.
Losers overwhelmed gainers 233 to 71 and 103 stocks were unchanged with 2.3 billion shares worth 15.0 billion baht (366.4 million dollars) traded.
The Thai baht weakened against the dollar amid moderate trading, dealer said.
The Thai unit closed Wednesday at 40.91-93 baht to one dollar compared to Tuesday's close of 40.85-89 baht.
The Thai baht also lost against the euro to close at 48.90-96 baht to one euro compare to the previous day's close of 48.80-92.
"Selling accelerated in the afternoon session as the Bank of Thailand forecast there would be more rate hikes," said Sukit Udomsirikul, senior strategist at Capital Nomura Securities.
The drop was led by the energy sector, which fell 2.97 percent. Communication shares lost 1.82 percent while construction materials dropped 1.70 percent.
Bangkok Bank shed 1.00 baht to close at 98.50 baht, while Kasikornbank added 0.50 baht to 59.50 baht, but Siam Comercial Bank lost 0.50 baht at 48.25 baht.
Siam Cement fell 6.00 baht to close at 220.00 baht, and PTT Plc plumeted 8.00 baht at 222.00 baht and PTT Exploration and Production plunged 16.00 baht to 416.00 baht. Thai Airways International edged down 0.25 baht at 37.75 baht.