* TSX rises 22.35 points, or 0.18 percent, at 12,723.40 * Six of the 10 main index sectors close higher * Index fell 0.76 percent on the week By Alastair Sharp TORONTO, Sept 13 (Reuters) - Canada's main stock index closed slightly higher on Friday, helped by a sharp jump in shares of fertilizer producer Potash Corp, but the gain was limited by a fall in heavily-weighted banks after data showed Canadians are more indebted than ever. Potash Corp jumped 2.3 percent to C$33.57 after reports surfaced that tycoon Suleiman Kerimov would sell his major stake in Russian potash producer Uralkali to investor Vladimir Kogan. The Potash Corp gain reflected optimism that a change in Uralkali's ownership might lead to it rejoining fellow potash producer Belaruskali in an export partnership, which would support prices for the crop nutrient. "When you have reports like this flying around, people tend to focus on the underlying fundamentals, which are that demand for potash is not going to go away in a hurry," said Elvis Picardo, strategist and vice president of research at Global Securities in Vancouver. "At some point, the stock has to be a screaming buy." The Toronto Stock Exchange's S&P/TSX composite index ended the session up 22.35 points, or 0.18 percent, at 12,723.40. It fell 0.76 percent on the week. Financial stocks were the biggest weight on the day as Statistics Canada said the ratio of household debt to income in Canada hit a record high in the second quarter. "If the Canadian consumer is strapped because of a huge debt load, then that has implications for the broad Canadian economy, and the banks are, of course, the biggest players here," Picardo said. Royal Bank of Canada slipped 0.7 percent to C$65.30, Toronto-Dominion Bank lost 0.4 percent to C$89.92, and Bank of Nova Scotia was down 0.2 percent at C$59.30. Oil and gas producers also helped the index rise, but Gareth Watson, vice president Of investment management and research at Richardson GMP, said their recent gains could be capped if it becomes clear that the United States will not make a military strike on Syria, which would pull down oil prices. The energy sub-index was up 0.25 percent, led by a 0.6 percent gain for Canadian Natural Resources to C$32.78, and Suncor Energy's 0.3 percent rise to C$37.35. Watson said the index has performed well in recent months. "I'm sure people would much rather where we are right now as opposed to the end of June, when we were down close to 12,000." Telecom stocks also helped the index rise, with Telus Corp up 0.8 percent at C$33.42 and Rogers Communications Inc gaining 0.8 percent to C$43.28. The stocks fell the previous day after a report that three foreign telecom companies had studied entering the Canadian market.