Building on initial gains, the Sensex at the Bombay Stock Exchange had surged 348 points, or 1.9 percent, to 18,344 in afternoon trade, a short while ago. Earlier in the morning, the Sensex had advanced 179 points, or 1 per cent, to 18,175, amid a sharp recovery in the rupee against the dollar, and rising global bourses.Stock markets in Japan, Singapore, Hong Kong, South Korea, Indonesia and Taiwan had gained between 0.4 percent and 1.2 percent, today, as weaker-than-expected US economic data triggered speculation that the US Federal Reserve, or central bank, may delay plans to reduce its monetary stimulus. The US Dow Jones Industrial Average had ended 0.3 per cent higher in yesterday's trade