* TSX falls 39.43 points, or 0.32 percent, to 12,273.24 * Seven of 10 major index sectors decline * Suncor up nearly 4 percent after earnings beat * CGI Group jumps 15 percent after results By John Tilak TORONTO, April 30 (Reuters) - Canada's main stock index stumbled on Tuesday as hard-hit gold producers dropped another 3 percent on lower gold prices, a fall that overwhelmed a jump in Suncor Energy Inc shares after a strong earnings showing. Suncor rose 3.8 percent as Canada's largest energy company increased its dividend 54 percent, said it would buy back C$2 billion ($1.97 billion) of its own shares and reported first-quarter earnings that surpassed expectations. Suncor had the biggest positive influence on the index. "It's a pleasant surprise," Irwin Michael, portfolio manager at ABC Funds, said of Suncor's results. "You need more of the big companies doing a little better than expected," he added. "We expect to see more dividend increases and better earnings as well." The index's materials sector, which includes mining stocks, lost 1 percent. In the group, miner Goldcorp Inc fell 2.6 percent to C$28.41. The price of gold fell as investors remained on the sidelines ahead of central bank meetings this week in Europe and the United States and support from the physical market softened while major buyer China was on holiday. Weak European economic data heightened expectations of an interest rate cut by the European Central Bank. Investors also eyed the U.S. Federal Reserve's Open Market Committee as it begins a two-day meeting on monetary policy. "If there is bad news on the economy, the expectation is that quantitative easing will stay in longer and interest rates will stay low for longer," Michael said. The Toronto Stock Exchange's S&P/TSX composite index was down 39.43 points, or 0.32 percent, at 12,273.24. Seven of the 10 main sectors on the index were in the red. Financials, the index's most heavily weighted sector, gave back 0.5 percent. Information-technology services company CGI Group Inc jumped 15 percent to C$30.96 after it reported strong fiscal second-quarter results.