TAIPEI, Dec 26 (Reuters) - Taiwan stocks edged up 0.2 percent in cautious trading on Thursday, extending the previous session's gain as investors awaited the central bank's rate decision later Thursday. As of 0215 GMT, the main TAIEX index rose 15.88 points to 8483.64. On Wednesday, the market closed up 0.2 percent at a nearly 29-month closing high. Among major winners, glasses and ceramics index showed the strongest performance, rising 2 percent. Automobiles were also up 0.8 percent, though construction was down 0.09 percent after the previous day's 0.78 percent fall. Taiwan's central bank will meet to set its policy interest rate after market close. Market watchers expect it will leave rates unchanged for the 10th quarter in a row. The Taiwan dollar was up T$0.042 to stand at T$30.005 to the U.S. dollar. (Reporting by Michael Gold; Editing by Anand Basu)