* TSX down 79.18 points, or 0.65 pct at 12,132.41
* All 10 main sectors lower, base-metal miners weigh (Adds details, analyst comment)
TORONTO, Sept 21 (Reuters) - Toronto’s main stock index drifted lower on Wednesday morning as cautious investors awaited a Federal Reserve policy statement that could include new measures to boost a struggling U.S. economy.
The Fed is expected to announce plans at 2:15 p.m. (1815 GMT) to shift its bond portfolio in favor of longer-dated issues and so push long-term interest rates — already near historic lows — even lower in a move known as Operation Twist. [ID:nFEDAHEAD]
“Everyone’s awaiting 2:15. People want to see what the Fed’s going to do, whether there’s this Twist, whether it’s QE3,” said said Irwin Michael, portfolio manager at ABC Funds
“The market continues to drift ... The volatility is pretty intense.”
At 10:37 a.m. (1437 GMT) The Toronto Stock Exchange’s S&P/TSX composite index .GSPTSE was down 79.18 points, or 0.65 percent at 12,132.41 . All 10 main sectors were lower.
Base-metal miners weighed on the materials sector as copper prices sagged to another 2011 low on demand worries fueled by prospects the euro zone debt crisis could derail the global recovery. [MET/L]
Teck Resources TCKb.TO, was down 2.7 percent at C$35.13, while First Quantum Minerals (FM.TO) fell 5.2 percent to 17.01.
Economic uncertainty also weighed on the industrials group, which slid 2.1 percent. Canadian National Railway (CNR.TO) was the top decliner as it fell 2.5 percent to C$66.91, while Canadian Pacific Railway (CP.TO) slid 3.6 percent to C$48.99.
Financials slipped 0.4 percent, with Bank of Nova Scotia (BNS.TO), down 0.5 percent at C$51.39 and Manulife Financial (MFC.TO), off 1.5 percent at C$12.26.
“It’s testing everyone. You’re 10 days from the end of the month and the end of the quarter. The bottom line is that everyone’s waiting for some catalyst, some hard-core information to give people comfort,” said Michael.
Among top advancers, miner Silver Wheaton SLW.TO added 2 percent to C$41.17, while Royal Bank of Canada (RY.TO) bucked the trend among banks, rising 0.3 percent to C$47.18.
($1=$1 Canadian) (Reporting by Trish Nixon; editing by Rob Wilson)