* TSX rises 4.91 points, or 0.04 percent, to 12,841.62 * Six of the 10 main index sectors advance * BlackBerry falls 0.5 pct, third day of declines * Husky jumps on Statoil oil discovery By Leah Schnurr TORONTO, Sept 26 (Reuters) - Canada's main stock index was little changed on Thursday with gains limited by a drop in BlackBerry's shares and market wariness about the impasse in budget and debt negotiations in the United States. BlackBerry fell for a third day in a row as markets continued to mull over a $4.7 billion bid to take the smartphone maker private. Doubts about the viability of the bid have emerged in recent days, and the stock gave up 0.5 percent to C$8.22 on Thursday. Investors also focused their attention on the latest political wrangling in the United States, which faces two separate and looming deadlines: to keep the government running beyond the end of the month, and to raise the debt ceiling to prevent a debt default. Some encouraging data south of the border helped offset the budget concerns as fewer Americans filed new jobless claims. While the day's economic data offered a mixed view of the recovery, analysts still believe the economy is managing to strengthen. "It's this constant struggle between policy uncertainties - be it monetary or fiscal - and the underlying fundamentals, which continue to point to slow but sustained improvement," said Craig Fehr, Canadian market strategist at Edward Jones in St. Louis, Missouri. "The markets are bouncing back and forth between that and finding some comfort in the fact that while Washington tends to be a very short-term distraction, the fundamentals, which are going to be a longer-term guide, are still pointing in the right direction." The Toronto Stock Exchange's S&P/TSX composite index ended up 4.91 points, or 0.04 percent, at 12,841.62. Six of the 10 main sectors on the index were higher. Sentiment for Canadian equities has been recovering after a sluggish first half of 2013. The TSX has gained more than 8 percent since hitting its low point for the year in June. Shares of Husky Energy jumped 4.1 percent to C$30.26 after its venture partner Statoil ASA said it has made a big oil discovery off Canada's East Coast. The index's energy sector broadly rose 0.5 percent. Gold-mining companies fell along with the price of the commodity, with Goldcorp down 1.3 percent at C$26.48, and Barrick Gold falling 1.1 percent to C$19.08.