* TSX falls 83.03 points, or 0.62 percent, to 13,240.98 * All 10 main index sectors decline * RBC has market's biggest negative influence * Encana slips after releasing production outlook By John Tilak TORONTO, Dec 11 (Reuters) - Canada's main stock index dropped on Wednesday, as weak commodity prices weighed on shares of natural resource companies and investors cautiously digested news of a provisional U.S. budget agreement. The bipartisan budget deal announced in the U.S. Congress on Tuesday marked the end of three years of gridlock and fiscal instability in Washington that culminated in October with a partial government shutdown. Further dragging on the market was a 4.1 percent decline in shares of Encana Corp after the company released its 2014 production outlook, predicting lower-than-expected output of high-value natural gas liquids and oil. Falling natural gas prices contributed to the decline. The Toronto stock market eased after three days of gains, and every major sector was trading in negative territory. "I see nothing but red," said John Ing, president of Maison Placements Canada. "The market was running on fumes and has been overbought." "It is in need of a pullback," said Ing, who didn't expect a rebound soon in energy and material stocks. The Toronto Stock Exchange's S&P/TSX composite index was down 83.03 points, or 0.62 percent, at 13,240.98. The energy group, down 0.7 percent, was hit by a drop in the price of oil. Canadian Natural Resources Ltd gave back 1 percent to C$34.42. The materials sector, which includes mining stocks, was down 0.6 percent. Barrick Gold Corp lost 1.6 percent to C$17.63, and Teck Resources Ltd declined 1.1 percent to C$25.28. Shares of banks and insurers gave back 0.6 percent. Royal Bank of Canada, the country's No. 1 lender, slipped 0.9 percent to C$68.76 as the biggest negative influence on the market. Manulife Financial Corp shed 0.5 percent to C$20.03.