U.S. stock index futures pointed to a lower open on Wall Street on Tuesday as investors braced for aluminum producer Alcoa's (AA.N) quarterly results that will kick-start a keenly awaited U.S. earnings season. Futures for the S&P 500 were down 0.9 percent, Dow Jones futures were down 0.8 percent and Nasdaq 100 futures were down 0.7 percent. Toxic debts could reach $4 trillion, new forecasts from the International Monetary Fund will report. The IMF said in January that it expected the deterioration in U.S.-originated assets to reach $2.2 trillion by the end of next year. A half-dozen bidders have emerged for American International Group Inc's (AIG.N) asset-management unit, but the sale of the $100 billion portfolio has become complicated by client withdrawals and declines in asset prices. General Motors Corp's (GM.N) request for $10.3 billion in loans under a U.S. Department of Energy program is now contingent on the automaker's 60-day restructuring review, a top GM executive said on Monday.
