The SET index outperforms Southeast Asian peers on Wednesday. (Bangkok Post file photo)

Thai shares lead the stock markets in Southeast Asia on Wednesday, with PTT Exploration and Production Plc emerging as the top boost to the index.

The Stock Exchange of Thailand index recovered from early weakness to close at 1,632.60, up 8.55 points or 0.53%, in turnover worth 48 billion baht.

PTTEP topped the most active stock after the company posted an 88.6% rise in full-year profit. PTTEP gained 2.50 baht or 2.11% to 121 baht, while Airports of Thailand Plc gained 1 baht or 1.5% to 69.75 baht.

Philippine shares recorded their worst fall in two weeks, as investors awaited a US Federal Reserve rates review and key Sino-US trade talks.

The Fed is widely expected to leave rates unchanged on Wednesday, as policymakers had made it clear that they plan a "patient" pause in rate hikes.

The central bank is taking a wait-and-see approach to further tightening in the face of a global economic slowdown, US federal government shutdown, trade tensions and waning business and consumer confidence.

Adding to investor caution is the start of a crucial round of Sino-US trade talks on Wednesday and Thursday.

Philippine shares fell as much as 1.7% on profit-taking before recovering partially to close 0.9% lower.

"We are seeing sales of shares of companies with large institutional following, investors are now being cautious about what will happen in the US Fed meeting," said Rachelle Cruz, a research analyst at AP Securities in Manila.

Cruz said a lot of funds from the profit-taking were invested in "third-liner stocks", with Premiere Entertainment emerging as one of the most actively traded stocks after a funding deal worth 15 billion pesos (US$286.67 million) with a Qatar-based investment management firm.

Index heavyweights BDO Unibank Inc and SM Prime Holdings lost 2.4% and 1.5%, respectively, while Premiere Entertainment closed at its highest level since November 1997.

Malaysian shares fell 0.4%, dragged by utility and basic material stocks.

Effects of the Sino-US trade war were seen with data showing Malaysia's exports to China, a major trading partner, contracted 0.5% annually in December, while shipments to the United States surged 13.5%.

Singapore shares closed 0.4% lower, with DBS Group Holdings and Singapore Press Holdings falling 1.2% and 2.4%, respectively.