* TSX ends down 50.04 pts, or 0.4 pct, at 11,280.64 * TSX hits lowest level since Oct. 5 at 11,256.72 * Financial shares hurt by euro zone woes * Gold miners, energy shares rise with gold, gas prices * Disappointing Facebook debut hurts sentiment By Jon Cook TORONTO, May 18 (Reuters) - Canadian stocks hit a seven-month low on Friday, erasing early mining and energy gains as concerns about Europe's deepening debt woes and after Facebook's disappointing market debut fueled a flight to safety. Nearly all of Canada's 10 main sectors finished in the red. Losses were led by the heavyweight financial group, which fell 1 percent as fears about Greece leaving the euro zone and Spain's fragile banking sector came back into focus as global equity markets tumbled in the afternoon. Royal Bank of Canada shares fell 0.5 percent to C$51.70, Bank of Nova Scotia was down 1.2 percent to C$51.11, Toronto-Dominion Bank slipped 0.9 percent to C$76.94 and insurer Sun Life Financial shed 1.9 percent to C$20.92. Manulife Financial Corp's shares slumped 1.5 percent to C$10.99 after a report put Canada's top insurer among a group of suitors expected to place first-round bids to buy ING Groep's Asia life insurance unit in a deal worth about $6.5 billion to $7 billion. A sloppy debut by Facebook Inc spoiled hopes that a spectacular open for the most-anticipated stock sale in years would brighten the mood in what has been a gloomy month for markets. "There was a negative aspect thrown onto the market by this whole deal," said Fred Ketchen, director of equity trading at ScotiaMcLeod. "From there it was just a case of reacting to the disappointment to the issue, the disappointment of the day, the disappointment of the week and the market is down." The Toronto Stock Exchange's S&P/TSX composite index closed down 50.04 points, or 0.4 percent, at 11,280.64. It touched 11,256.72, its lowest level since Oct. 5. The TSX finished the week down 3.5 percent - its biggest weekly drop since the end of November. It has fallen 8.5 percent in May as conditions in Europe have unraveled. A ratings downgrade of 16 Spanish banks by Moody's Investors Service on Thursday raised investor fears the sector may need a bailout that would strain Madrid's already stretched finances. In addition, a weekend meeting of the Group of 8 major industrial economies may have made some investors wary of holding positions open until Monday. Germany's finance minister, Wolfgang Schaeuble, one of Greece's harsher critics, said market unrest fueled by the euro zone debt crisis could last another year or two. "There's a lot of talk about what the downgrades are going to bring from the banking sector in the European community so people are still sitting on the sidelines," said Sid Mokhtari, director of institutional equity research at CIBC World Markets. "Investors are still expecting darker days ahead." Losses were capped by gold miners and energy firms, which rose with a rebound in gold and natural gas prices. Friday's most influential gainers included New Gold Inc , up 4.8 percent to C$8.36, First Quantum Minerals , up 1.4 percent to C$17.48, Yamana Gold, up 1.1 percent at C$13.94, Eldorado Gold, which climbed 1 percent to C$11.12, and Pacific Rubiales Energy Corp, which jumped 2.6 percent to C$25.93. In other news, shares of Canadian Pacific Railway tumbled 3.1 percent to C$74.11 following a boardroom shakeup on Thursday at Canada's second largest railway, spurred by a brash New York hedge fund that analysts said could be a warning signal for other members of the Canadian corporate establishment.