SE Asia Stocks-Most markets set for losses in 2015, Vietnam outperforms

HANOI, Dec 31 (Reuters) - Southeast Asian stock markets ended down in thin trade on Thursday as investors stayed away ahead of holidays, with all markets posting losses in 2015 except for Vietnam. Singapore's key Straits Times Index dipped 0.1 percent in mixed trade, with losses in most big caps offseting gains in several blue chips. The index, Southeast Asia's worst performer this year, posted a 14.34 percent drop in 2015. The stock market traded for half a day on Thursday and will be s