O/RGOL/ The Toronto Stock Exchange's S&P/TSX composite index .GSPTSE ended flat on Tuesday as mixed U.S. inflation data stoked worries that price pressures are not cooling as fast as central banks would wish. Energy company Suncor Energy Inc SU.TOreported a better-than-expected fourth-quarter profit on Tuesday, helped by higher crude prices. Feb 15 (Reuters) - Futures for Canada's resource-heavy main stock index fell on Wednesday as commodity prices declined, while investors worried about the probability of further monetary tightening by central banks.