TSX down for third day as energy and rails weigh

By Alastair Sharp TORONTO (Reuters) - Canada's main stock index fell for a third straight session on Wednesday, with heavyweight energy and railway companies among the biggest losers as crude prices slipped and investors worried about economic growth. The Toronto Stock Exchange's S&P/TSX composite index ended down 62.43 points, or 0.42 percent, at 14,980.72. "Valuations have been somewhat stretched and we wouldn't be surprised to see a correction somewhere along the way h