Singapore shares closed at a near three-week high on Monday, boosted by the industrial and real-estate sectors, while Thailand retreated after a surprise fall in its customs-cleared exports for September.

The city-state's benchmark closed up 0.8%.

On Monday, Singapore state investor Temasek Holdings said it was offering to take control of Keppel Corp in a $3 billion deal that will shore up support for the conglomerate, which is battling difficult business conditions.

"I think the Temasek-linked companies are rising in the hope that they could get a similar offer from Temasek," said Linus Loo, head of research at Lim & Tan Securities said.

Following the offer, utility firm Sembcorp Industries rose 10.1%, while shipbuilding unit Sembcorp Marine posted its best intraday rise since February 2017.

"Traders are chasing the stocks on speculation of possible restructuring between Keppel Corp, Sembcorp Industries and Sembcorp Marine," said Kee Yan Yeo, equity market strategist at DBS Bank.

Temasek Holdings owns 49.45% and 60.98% stakes in Sembcorp Industries and Sembcorp Marine, respectively, according to Refinitiv Eikon data.

Indonesian stocks clocked their seventh consecutive session of gains, finishing marginally higher, ahead of a central bank policy meeting later this week. A small majority of economists expect Bank Indonesia to cut its benchmark rate for the fourth straight month to support the economy, a Reuters poll showed on Monday.

Financial and communication firms were the biggest gainers, with Bank Central Asia hitting its highest in nearly three months, while Unilever Indonesia gained 0.7%.

Elswhere, Thai stocks fell for a third straight session after data showed that the country's customs-cleared exports declined for a second consecutive month in September. Consumer and utilities firms were among the top losers, with real estate developer Asset World Pcl and electricity generator Gulf Energy Development declining 6.1% and 1.2%, respectively.

Meanwhile, China's central bank on Monday unexpectedly kept its new benchmark lending rate unchanged, even as data released last week showed growth in the world's second biggest economy slowed to its weakest pace in almost three decades in the third quarter.

Vietnam stocks fell 0.6%, dragged by heavy losses in financials.

Bank for Foreign Trade of Vietnam and Bank for Investment and Development of Vietnam were among the top losers, slipping 0.9% and 2%, respectively. Philippine stocks edged up, while Malaysian shares were little changed.