Extending early gains, the Sensex at the Bombay Stock Exchange spurted a hefty 366 points, or 2.3 percent, to 16,386 in afternoon deals, a short while ago. In the morning, the Sensex had opened a good 169 points higher, at 16,190, on strong buying by funds, driven by hopes of a rate cut by the Reserve Bank. The rupee stabilising against the dollar, and firm Asian bourses also helped lift investor sentiment.Key stock indices in Japan, Hong Kong, Indonesia, Taiwan and Singapore were up by between 0.8 percent and 2.7 percent, after finance ministers and central bank governors from the world's leading economies pledged to help resolve Europe's financial crisis.