* TSX up 12.21 points, or 0.09 percent, at 13,373.84 * On track for a 0.2 pct slip on week after three weeks of big gains * Barrick again weighs after announcing planned stock sale By Alastair Sharp TORONTO, Nov 1 (Reuters) - Canada's main stock index slipped on Friday with shares in the world's largest gold miner, Barrick Gold Corp, tumbling after the company said it would use a stock sale to raise cash. While banks and industrial stocks gained, Barrick's 7 percent fall to C$18.85 and smaller declines from a string of other gold miners put the index on track for a small weekly decline after three weeks of moves higher. Barrick plans to issue more than $3 billion in stock to help pay down debt. The company's stock fell almost 6 percent on Thursday after saying it would stop development of its Pascua-Lama mine in South America indefinitely, a surprise reversal on a project that has already cost Barrick more than $5 billion. Goldcorp lost 4.8 percent to C$25.29. The price of bullion was at a two-week low. The index had risen sharply in October, outperforming U.S. indices after lagging behind its southern neighbor in recent years because of the poor performance of resource-based companies that make up a large chunk of the Canadian exchange. Signs of global economic recovery should boost Canada's mining and energy companies, while investors have been emboldened by the U.S. and Canadian central banks both suggesting that supportive monetary policy will remain in place for longer. Domestic and Chinese manufacturing data both showed growth in October, helping boost industrial stocks. Canadian National Railways Co gained 1.8 percent to C$116.49, a day after it reached a tentative labor contract with a union after weeks of negotiations. The pace of growth in Canadian factories hit its strongest level in two and a half years, while China's numbers backed the country's aim of sustainable growth. "In theory, if we are seeing greater stability out of China we should see more stable demand for commodities and perhaps a slight pick up in commodity prices," said Philip Petursson from the portfolio advisory group at Manulife Asset Management. But he said a growing supply of copper and Canadian miners' focus on lowering costs could limit any climb in stocks. Construction and engineering company SNC-Lavalin Group Inc gained 1.2 percent to C$44.34 despite reporting a quarterly loss as cost overruns hurt. The company had slashed its 2013 outlook in mid-October. The Toronto Stock Exchange's S&P/TSX composite index was up 12.21 points, or 0.09 percent, at 13,373.84 by mid-morning. It is on track for a 0.2 percent slip for the week, though it is just off its highest levels in more than two years. Banks were among the most influential gainers, with Royal Bank of Canada up 1 percent at C$70.77 and Toronto-Dominion Bank gaining 0.9 percent to C$96.44. Manulife's Petursson said all-time highs reached by bank stocks made them appear expensive, given the amount of debt Canadians are looking to pay down. "It's difficult to justify their valuation, especially in light of the consumer debt situation, which could be a bit of a drag for the banks going forward," he said.