(Updates prices, sectors) July 16 (Reuters) - Canada’s main stock index was muted on Friday, and on track to post a weekly loss of half a percent as energy stocks took a beating from lower oil prices. * The energy sector tumbled nearly 6% this week and is set for its worst week in nearly four months, as crude prices tumbled. * However, the sector gained 0.6% on Friday and kept the main index afloat. * At 9:42 a.m. ET (1342 GMT), the Toronto Stock Exchange’s S&P/TSX composite index was up 2.83 points, or 0.01%, at 20,186.55. * Data showed the nation’s wholesale trade increased by 0.5% in May from April on the food, beverage and tobacco subsector as well as machinery and equipment. * The materials sector, which includes precious and base metals miners and fertilizer companies, lost 0.8% as gold futures fell 0.2% to $1,824.5 an ounce. * On the TSX, 133 issues were higher, while 87 issues declined for a 1.53-to-1 ratio favouring gainers, with 12.22 million shares traded. * The largest percentage gainer on the TSX was Methanex Corp , which jumped 6.2%, after the methanol producer raised its quarterly divided. * Alt-energy producer Westport Fuel Systems Inc followed with a 3.3% rise. * Turquoise Hill Resources Ltd fell 12.7%, the most on the TSX, after multiple brokerages cut their price targets on the stock. The second biggest decliner was B2Gold Corp, down 4.3% after National Bank of Canada cut its price target on the miner. * The most heavily traded shares by volume were Royal Bank of Canada, B2Gold Corp and Baytex Energy Corp . * The TSX posted no new 52-week high and no new low. * Across all Canadian issues there were 50 new 52-week highs and four new lows, with total volume of 22.06 million shares. (Reporting by Amal S in Bengaluru; Editing by Amy Caren Daniel)