CANADA STOCKS-TSX nears six-year high as Suncor shares, oil prices gain

* TSX rises 52.20 points, or 0.36 percent, to 14,583.11 * Five of 10 main index sectors advance * Cameco slips after reporting quarterly results By John Tilak TORONTO, April 29 (Reuters) - Canada's main stock index climbed on Tuesday to its strongest level in almost six years as robust results from Suncor Energy Inc boosted shares of the oil producer and higher oil prices lifted other energy stocks. Suncor's stock hit its highest since 2011 after the company reported late on