* TSX falls 24.79 points, or 0.20 percent, to 12,145.65 * Canadian Natural off 1.5 pct after raising capital budget * Eight of 10 main sectors decline By John Tilak TORONTO, Dec 4 (Reuters) - Canada's main stock index fell on Tuesday, led down by a drop in Canadian Natural Resources Ltd on concerns about its 2013 outlook, while the overall market continued to fret about the chances U.S. politicians would be able to resolve the country's looming fiscal crisis. Shares of Canadian Natural fell 1.5 percent to C$27.77 on disappointment that the 10 percent spending increase outlined by the country's biggest independent oil and gas producer for next year and the increases in production it forecast were too small. "Evidently the market felt that was a little disappointing," said Gavin Graham, president of Graham Investment Strategy. The energy sector, which played the single biggest role in leading the index lower, was down 0.8 percent. But the broader concern for investors was the risk that U.S. politicians would fail to reach a deal to prevent the trigger of automatic government spending cuts and tax increases in early 2013 from tipping the economy back into recession. On Monday, the White House dismissed a proposal from Republicans that included tax reforms and spending cuts, saying it did not meet President Barack Obama's pledge to raise taxes on the wealthiest Americans. [ID: nL1E8N3GZ4] "It's as bad as the NHL hockey discussions. Both sides have hardened their positions when there were expectations of hope," said John Ing, president of Maison Placements Canada. "They're running out of time. There is maybe a week left before something meaningful can be done. It is a worry," he added. The Toronto Stock Exchange's S&P/TSX composite index was down 24.79 points, or 0.20 percent, at 12,145.65. Eight of the 10 main sectors on the index declined. ShawCor Ltd was the second biggest drag. The provider of services to the energy industry shed 15.6 percent after it said it was unlikely to sell itself following a review of strategic alternatives that it had undertaken. Bank of Montreal gained 0.9 percent after Canada's fourth-largest lender reported a 41 percent rise in quarterly profit, topping estimates, as wholesale banking income doubled and loan-loss provisions plunged.