Broader Asia <.MIAPJ0000PUS> was down 0.4%, as investors booked profits on the last trading day of the decade. Most Southeast Asian benchmarks were poised to end the year higher.

Singapore's market shut early on Tuesday, while most other markets in the region are closed on account of New Year's Eve.

Malaysian benchmark marked its worst session in more than a month, with all sectors trading in the red. The index recorded losses of 5.4% for the year.

Public Bank Bhd fell 1.7%, while Sime Darby Plantation, the world's largest oil palm planter by land size, slid 2%.

"While market volumes are predictably light, investors continue to strike a year-end cautionary tone as December optimism is gradually giving way to 2020's uncertainty," Stephen Innes, chief Asia market strategist at AxiTrader, said in a note.

On the trade front, White House's trade adviser said on Monday the U.S.-China Phase 1 trade deal would likely be signed in the next week, but said a confirmation would come from President Donald Trump or the U.S. Trade Representative.

Any signs of easing trade tensions between Washington and Beijing are a major boon for Southeast Asian economies, which count China as their top trading partner.

Meanwhile, data on Tuesday showed factory activity in China, expanded for a second straight month in December, as production quickened and export orders rose.

Singapore's benchmark index was flat, but gained 4.9% for the year. Industrial stocks offset gains in financials, with Jardine Strategic Holdings slipping 1.6%.

The Vietnam index fell 0.3%, but was on track to post a 7.8% gain for 2019, outperforming its peers by a vast margin.

Financial and consumer stocks accounted for most of the losses on the benchmark, with Saigon Beer Alcohol Beverage Corp falling 0.9%.

(Reporting by Shruti Sonal in Bengaluru; editing by Uttaresh.V)

By Shruti Sonal