(Updates prices, adds sectors) April 23 (Reuters) - Canada’s main stock index gained on Friday as material stocks rose tracking gold prices and a jump in factory sales in March helped boost recovery optimism. * At 9:45 a.m. ET (13:45 GMT), the Toronto Stock Exchange’s S&P/TSX composite index was up 42.4 points, or 0.2%, at 19,074.56. * The materials sector, which includes precious and base metals miners and fertilizer companies, added 0.6% as gold futures rose 0.3% to $1,786.20 an ounce. Gold prices were set for their third weekly gain on lower Treasury yields. * Canadian factory sales most likely rose 3.5% in March from February, Statistics Canada said in a flash estimate on Friday. The increase is mostly attributed to higher sales in transportation equipment and the petroleum and coal product industries. * The energy sector was unchanged as U.S. crude prices were up 0.1% a barrel, while Brent crude lost 0.1%. * The financials sector gained 0.1%. The industrials sector remain unchanged. * On the TSX, 115 issues were higher, while 106 issues declined for a 1.08-to-1 ratio favouring gainers, with 10.97 million shares traded. * The largest percentage gainers on the TSX were Turquoise Hill Resources, which jumped 2.3% and OrganiGram Holdings, which rose 2.2%. * Winpak Ltd fell 2.7%, the most on the TSX, while the second biggest decliner was Sunopta Inc, down 1.6%. * The most heavily traded shares by volume were Tetra Bio-Pharma, Nevada Copper and Royal Bank of Canada. * The TSX posted five new 52-week highs and no new lows. * Across all Canadian issues, there were 18 new 52-week highs and six new lows, with total volume of 28.63 million shares.