TORONTO, Feb 21 (Reuters) - Toronto Stock Exchange S&P/TSX composite index .GSPTSE :
* Falls 7.56 points, or 0.04 percent, to 17,936.50 at open.TORONTO, Feb 21 (Reuters) - Toronto Stock Exchange S&P/TSX composite index .GSPTSE :
* Unofficially closes down 100.53 points, or 0.56 percent, at 17,843.53.