* TSX ends down 5.95 points, or 0.04 percent, at 13,859.12
* Eight of the TSX's 10 main groups fall; energy offsets
TORONTO, Aug 31 (Reuters) - Canada's main stock index ended barely lower on Monday, as solid gains among heavyweight oil and gas companies offset falls in most other sectors.
The Toronto Stock Exchange's S&P/TSX composite index unofficially closed down 5.95 points, or 0.04 percent, at 13,859.12. (Reporting by Alastair Sharp; Editing by Chizu Nomiyama)