Taiwan tightened rules on short-selling to prop up the stock market ahead of a presidential poll, but some fund managers said on Tuesday that the move would achieve little as foreign investors remain bearish. The main TAIEX index ended down 42.61 points at 7,000.03, after opening up 0.31 percent. Financial shares slipped 0.15 percent. Taiwanese and Chinese banking regulators are meeting on Tuesday to discuss ways to build closer ties. The electronics sub-index shed 1.22 percent, however LCD maker Chimei Innolux Corp edged up 2.76 percent on a report that it is a major target of foreign private equity funds. Rival AU Optronics Corp was also up 2.62 percent. The Taiwan dollar was weakened by 0.16 percent to T$30.290.