* TSX down 171.25 points, or 1.37 percent, at 12,364.15
* Eight of the TSX's 10 main groups fall
TORONTO, Feb 9 (Reuters) - Canada's main stock index on Tuesday fell to its lowest since late January, again weighed down by bank and energy company shares as investors globally retreat from equity markets.
The most influential movers on the index were its heavyweight banks, with the financials group down 1.4 percent overall, while the energy sector retreated 1.8 percent, extending Monday's losses.
Those two sectors account for a combined 56 percent weighting of the Toronto Stock Exchange's S&P/TSX composite index market. In all, eight of the TSX's 10 main sectors fell.
Faced with record low prices for heavy crude, Canadian energy companies are sacrificing other parts of their business to keep higher-cost oil sands production going and safeguard the billions already invested in these multi-decade projects.
Suncor Energy Inc lost 2.1 percent to C$30.71 and Canadian Natural Resources fell 2.5 percent to C$28.50.
Royal Bank of Canada fell 1.3 percent to C$68.36, Toronto-Dominion Bank declined 1.4 percent to C$50.77 and Bank of Nova Scotia fell 1.8 percent to C$54.66.
Insurers also fell, with Manulife Financial Corp down 2 percent to C$17.87 and Sun Life Financial Inc off 1 percent to C$38.09.
The losses echoed falls in Europe, where trading in several Italian banks was suspended after sharp drops, and many investors believe signs of stress in the market for credit default swaps point to further declines ahead.
At 10:27 a.m. EST (1527 GMT), the S&P/TSX composite index was down 171.25 points, or 1.37 percent, at 12,364.15.
It fell as low as 12,307.09 in early trade, its lowest level since Jan. 27, with decliners outnumbered advancers by more than 4-to-1.
Fortis Inc shares fell 8.4 percent to C$37.92 after the utility said it would buy a U.S. power transmission company.
Shares in Agrium Inc fell 2.4 percent to C$114.30 after the fertilizer and farm products retailer forecast lower-than-expected profit for 2016, blaming weak prices.
The materials group, which includes precious and base metals miners and fertilizer companies, lost 2.7 percent.
Cineplex Inc rose 5.9 percent to C$49.45 after the movie theater operator reported better than expected fourth quarter revenue and raised its dividend. (Reporting by Alastair Sharp Editing by W Simon)