* TSX down 49.16 points, or 0.41 percent, at 11,964.66
* Energy sector leads TSX lower as oil below $80
* China policy tightening, U.S. Fed in focus (Adds details, quote)
By Jennifer Kwan
TORONTO, March 15 (Reuters) - Toronto's main stock index retreated on Monday morning as oil and base metals prices declined due in part to worries about monetary policy tightening in China, pressuring commodity shares.
Canadian Natural Resources (CNQ.TO) fell 2 percent to C$73.23 and Suncor Energy (SU.TO) dropped 1.6 percent to C$31.32, while EnCana Corp (ECA.TO) shed 1 percent to C$33.87.
The index's oil and gas group fell 1.1 percent.
Its materials group, home to miners and fertilizer companies, dropped 0.6 percent as Potash Corp of Saskatchewan (POT.TO) fell 0.7 percent to C$127.09, and First Quantum Minerals (FM.TO) lost 0.3 percent to C$87.79. [MET/L] [GOL/]
Toronto followed global markets, which faltered on concerns about monetary tightening in China and caution ahead of U.S. and Japanese central bank policy meetings this week. [MKTS/GLOB]
"If China were to tighten, the sense is that it would slow demand for commodities that we produce in abundance here in Canada," said Paul Taylor, chief investment officer at BMO Harris Investment Management Inc.
"The question is where does it all net out in terms of the sustainability of the economic recovery," he added.
Oil prices dropped below $81 a barrel, pulled lower in part by a firm U.S. dollar [O/R], while copper prices were undermined by the China worries. [MET/L]
At 10:12 a.m. (1412 GMT), the Toronto Stock Exchange's key S&P/TSX composite index .GSPTSE was down 49.16 points, or 0.41 percent, at 11,964.66.
The index's close above 12,000 on Friday was its highest finish in about 18 months.
($1=$1.02 Canadian) (Reporting by Jennifer Kwan; editing by Peter Galloway)