* TSX rises 20.49 points, or 0.16 percent, to 12,869.38 * Six of 10 main index sectors advance * Suncor has biggest positive influence on market * BlackBerry drops after investors have doubts about deal financing By John Tilak TORONTO, Sept 25 (Reuters) - Canada's main stock index advanced on Wednesday, led by gains in the natural resource sectors, as investors mulled budget talks in Washington and when the U.S. Federal Reserve's monetary policy might change. BlackBerry shares gave back nearly 3 percent as skepticism grew about the financing of a takeover deal it announced earlier this week. Investors also digested data showing orders for long-lasting U.S. manufactured goods barely grew in August, as well as a report indicating sales of new single-family homes in America rose in August but held near their lowest levels this year. Investors hoped for a resolution of the U.S. budget battle and more clarity about the Fed's stimulus program. "There will be brinkmanship," said Sal Masionis, a stockbroker at Brant Securities, of the budget negotiations. "That's not good for the market. The market hates brinkmanship and uncertainty." The Toronto Stock Exchange's S&P/TSX composite index was up 20.49 points, or 0.16 percent, at 12,869.38. Six of the 10 main sectors on the index were in the red. Masionis sees the uncertainty weighing on the Canadian market but added that there could be a rally towards the end of the year. The materials sector, which includes mining stocks, added 0.7 percent. Teck Resources Ltd jumped 1.8 percent to C$28.70, and Goldcorp Inc climbed 1.1 percent to C$26.67. Shares of energy producers benefited from a higher oil price, rising 0.5 percent. Suncor Energy Inc climbed 1 percent to C$36.99, having the biggest positive influence on the market. Canadian Natural Resources Ltd advanced 0.9 percent to C$32.45. But shares of telecoms providers declined 0.7 percent. Telus Corp gave back 1.6 percent to C$34.98, and BCE Inc fell 0.6 percent to C$44.31. BlackBerry slipped to C$8.53 after a Globe and Mail report said Fairfax Financial Holdings Ltd was seeking more than $1 billion in equity investments from institutional investors to back its preliminary $4.7 billion plan to acquire the smartphone maker. The report cited unnamed sources saying that as of Tuesday only one pension fund, the Ontario Teachers' Pension Plan, was seriously considering joining a takeover consortium. Teachers declined to comment on the report.