TORONTO, Aug 2 (Reuters) - Canada's main stock index suffered its biggest one-day loss in more than a month on Tuesday, as its heavyweight energy sector weighed heavily with U.S. crude settling at under $40 a barrel on persistent supply concerns.
The Toronto Stock Exchange's S&P/TSX composite index .GSPTSE unofficially closed down 105.73 points, or 0.73 percent, at 14,477.01. The energy sector fell 2.4 percent.