CANADA STOCKS - TSX falls, Canadian Natural Resources weighs
May 3 (Reuters) - * The Toronto Stock Exchange's S&P/TSX fell 6.46 points, or 0.04 percent, to 15621.47. * The biggest contributor to the TSX loss was Canadian Natural Resources with 7.88 net index points. Energy was the top sector contributor with 19.59 net points. * Leading the index were Shopify Inc, up 7.8 percent, Cott Corp, up 6.1 percent, and Maple Leaf Foods Inc, higher by 4.7 percent. * Lagging shares were Crescent Point Energy Corp, down 7.8 percent, Norbord Inc, down 6.2 percent, and Advantage Oil & Gas Ltd, lower by 6.0 percent. * On the TSX 109 issues advanced and 134 declined as a 0.8-to-1 ratio favored decliners. There were 2 new highs and 3 new lows, with total volume of 234.1 million shares. * The most heavily traded shares by volume were Bombardier Inc, Cenovus Energy Inc and Crescent Point Energy Corp. * The TSX's energy group fell 2.98 points, or 1.49 percent, while the financials sector slipped 0.31 points, or -0.11 percent. * West Texas Intermediate crude futures rose 0.82 percent, or $0.56, to $68.49 a barrel * The TSX is off 3.6 percent for the year. (Editing by Alden Bentley)