The Sensex at the Bombay Stock Exchange surged 172 points, or 1 per cent, to 17,472 in early trade, on Thursday morning, on sustained buying by funds and retail investors, driven by some encouraging quarterly corporate earnings and positive Asian bourses.Later, the Sensex trimmed some of its initial gains, to stand 117 points, or 0.7 percent in positive territory, at 17,418 in afternoon deals, a short while ago.Telecom stocks were mixed after the Supreme Court cancelled 122 licenses issued to telecom companies in 2008. But Bharti Airtel gained nearly 8 percent in volatile trade.Regional markets in Japan, China, Hong Kong, Indonesia, South Korea, Taiwan and Singapore were up by between 0.5 percent and 1.5 percent, today, as positive global economic data soothed fears about the global economy. The US Dow Jones Industrial Average had gained 0.7 per cent, overnight.