The Sensex at the Bombay Stock Exchange plunged 252 points, or 1.5 per cent, to 16,076 in the opening trade, today, on fresh selling by foreign funds and retail investors, amid rupee weakness, and in tandem with falling global markets. Later, the Sensex lost some more ground, to stand 334 points, or 2.1 per cent in the negative zone, and slip below the 16,000 level, at 15,994 in afternoon deals, a short while ago.Other Asian stock markets in Japan, China, Hong Kong, Indonesia, Singapore, Taiwan and South Korea also suffered significant losses of between 0.8 percent and 3.2 percent, today, after Greece failed to form a government, setting the stage for a June election that could raise the risk of that country abandoning the euro. Key European markets in the UK, Germany and France were down by between 0.9 percent and 1.3 percent, in intra-day trade, today, on deepening speculation that Greece could leave the euro currency bloc. Over in the US, the Dow Jones Industrial Average had lost 0.5 per cent in yesterday's trade.