Thai stocks ended down 1.06 percent on Monday as bearish foreign investors pushed bank stocks lower amid a slew of quarterly earnings, analysts said.
Profit taking sent Bank of Ayudhya down 0.7 percent to 13 baht, while state-run Thai Military Bank fell 2.3 percent to 4.24 baht despite strong first quarter results.
Shares in other big banks also dropped ahead of their results due out later this week.
Bangkok Bank, the country's biggest bank, gave up 1.96 percent to end at 100 baht. Number two Krung Thai Bank dropped 1.8 percent to 11.1 baht.
"It was profit taking on bank stocks. The market took a breather after last week's rally which should continue tomorrow," said analyst Wiriya Lappromratana at Kiatnakin Securities.
The benchmark Stock Exchange of Thailand (SET) composite index ended down 7.55 points, or 1.06 percent, at 704.65.
The big-cap SET 50 index lost 0.94 percent to 47.38 points.
Turnover fell to 22 billion baht ($558 million) from 24.3 billion baht on Friday.
"Local investors were concerned about foreign selling and that caused quick profit-taking this morning," said Piti Ketsiri, head of equity sales at BT Securities.
The market lost momentum after it failed to break the 719 point level in early trade, Piti said.
Foreign investors were net sellers of Thai stocks worth 928 million baht on Friday. It was third straight day of net selling by overseas investors, bringing their net selling position to 21.7 billion baht this year.
Finance firm Asia Credit PCL, the second biggest gainer of the day, closed up 28.4 percent at 10.4 baht on solid first quarter results. But analysts said the share price may be overvalued.
Shares in Thailand's Shin Satellite PCL, Asia's second biggest satellite operator, gained 1.74 percent to 29.25 baht on market rumours that its planned share sale would be priced at more than 10 percent above their current market price. The company denied the rumours.