The main TAIEX index ended up 9.34 points at 7,188.21, extending gains from the over-two-month closing high hit in the previous session. The construction and machinery sectors were the top gainers, adding 1 percent and 0.67 percent, respectively. LCD maker Chimei Innolux erased earlier gains to fall 0.78 percent on media reports it had asked the government for loan extensions. Smaller rival AU Optronics jumped 4.38 percent. Its ADRs surged 9.37 percent in New York trading. The Taiwan dollar climbed by T$0.111 to trade at T$29.94. Foreign investors were net buyers on Tuesday, bringing their total buying to T$9.63 billion this month. Taiwan holds presidential elections this Saturday in a vote that will determine whether the island deepens economic integration with mainland China or embarks on a period of more tense and possibly fractious relations.