Thai share prices closed 0.26 percent lower on Friday in line with falls on regional markets amid persistent fears that US interest rates will go higher, dealers said.
They said the Thai market was also under pressure due to political uncertainty as the country's three most powerful courts this week rejected a proposed October 22 date for new elections.
The Stock Exchange of Thailand (SET) composite index fell 1.97 points to 746.33, while the blue chip SET 50 index lost 1.40 points to 516.61.
Losers outnumbered gainers 195 to 126 and 124 stocks were unchanged with 2.8 billion shares traded with 13.2 billion baht (433 million dollars).
The Thai baht closed Friday at 38.12-16 to the dollar, little changed from Thursday's 38.08-11. Against the euro, the Thai unit closed at 48.60-60, compared with 48.69-74.
"Buying sentiment was sluggish as investors remained jittery over US rate hikes," said Sukhbir Khanijoh, a senior analyst at Trinity Securities.
Asian stocks plunged this week as US inflation data rattled Wall Street and raised the spectre of further interest rate increases by the Federal Reserve.
Sukbir said the Thai market also declined Friday amid growing political uncertainty after the courts rejected a proposed date for a new election.
Earlier in the month, Thailand's Constitutional Court declared troubled snap polls on April 2 invalid and ordered a new election. The snap elections were called by Prime Minister Thaksin Shinawatra in a bid to silence critics.
Shares in Thailand's top energy firm PTT were unchanged at 250.00 baht and its subsidiary PTT Exploration and Production also remained flat at 116.00.
Thailand's top lender Bangkok Bank lost 1.00 to 110.00, and Siam Commercial Bank, the fourth-largest lender, was unchanged at 61.50.
Thai Airways International declined 1.00 to 45.50.