Erasing most of its early gains, the Sensex at the Bombay Stock Exchange ended a modest 23 points, or 0.1 percent higher, at 16,994, today. The Nifty at the National Stock Exchange rose 8 points, or 0.2 percent, to 5,089.Stock markets in Japan, China, Hong Kong, South Korea and Singapore gained between 0.3 percent and 2.2 percent.