GLOBAL MARKETS-U.S. stocks, oil swoon on anxiety over economy

* S&P posts worst day in four months * S&P down 4 percent during streak; Dow falls over 200 points * Oil prices tumble after Chinese data spurs demand worries * Euro falls on nagging anxiety about region's debt crisis * Renewed safe-haven bids for gold and U.S., German debt By Richard Leong NEW YORK, April 10 (Reuters) - Wall Street's recent sell-off accelerated on Tuesday, with the benchmark S&P posting its worst day in four months, stung by worries about slowing econ