TORONTO (Reuters) - Canada's main stock index extended its early losses on Friday, falling 1 percent in a broad sell-off after contracting U.S. retail sales data signaled flagging momentum in Canada's largest export market. At 10:04 a.m. the Toronto Stock Exchange's S&P/TSX composite index was down 125.18 points, or 1 percent, at 12,356.19. All ten main sectors were in the red. (Reporting by Alastair Sharp; Editing by Nick Zieminski)