* TSX falls 159.64 points, or 1.35 pct, to 11,661.45
* Eight of 10 sectors lower; energy, materials weigh
By Julie Gordon
TORONTO, Sept 28 (Reuters) - Toronto's main stock index retreated further on Wednesday afternoon, pressured by falling commodity prices, as uncertainty over Europe's debt crisis continued to dog the market.
The TSX had rallied more than 3 percent in the previous two sessions on hopes that euro zone leaders were readying decisive action to tackle the region's debt woes.
But investors pulled back on Wednesday, as markets focused on international auditors heading for Athens to inspect the Greek government's austerity plan, while a German suggestion that a new bailout may be renegotiated caused consternation. [MKTS/GLOB]
"There hasn't been any concrete news or any tangible solution out of Europe, so I think that manifests itself in a big retreat in commodity prices," said Elvis Picardo, vice president of research at Global Securities. "Obviously that is having a very big impact on the level of the TSX."
At 3:00 p.m. (1900 GMT), the Toronto Stock Exchange's S&P/TSX composite index .GSPTSE was down 1.35 percent, or 159.64 points, at 11,661.45. Eight of the 10 main groups were lower.
Resource issues weighed as economic uncertainty and a strong U.S. dollar pressured commodity prices. The materials sector fell 2.86 percent, while energy issues slid 2.03 percent. [O/R]
Fertilizer producer Potash Corp (POT.TO) was the heaviest decliner, down 3.4 percent at C$47.80, while Barrick Gold (ABX.TO) slipped 1.73 percent to C$47.72 and Teck Resources (TCKb.TO) fell 4.18 percent to C$30.72. Suncor Energy (SU.TO) lost 2.75 percent to C$27.60.
"Crude oil and commodities have been moving in line with the outlook for global growth," said Picardo. "So that's at the bottom of this whole negative scenario."
Copper CMCU3 was down 4.5 percent and gold XAU= dropped 1.5 percent as worries about Europe's debt situation weighed on both base and precious metals. [MET/L] [GOL/]
Financials slipped 0.53 percent, with Canada's largest bank, Royal Bank of Canada (RY.TO), falling 1 percent to C$47.60 and Bank of Nova Scotia (BNS.TO) slipping 0.94 percent to C$52.47.
Shares of Yellow Media Inc YLO.TO plunged 50.88 percent to 28 Canadian cents after the debt-laden telephone directory publisher said it would take a C$2.9 billion ($2.8 billion) charge in the third quarter. [ID:nL3E7KS23A]
In the latest economic data, new orders for long-lasting U.S. manufactured goods slipped in August on weak demand for motor vehicles, but a rebound in a gauge of business spending suggested the U.S. economy would avoid another recession. [ID:nS1E78R088]
($1=$1.03 Canadian) (With additional reporting by Trish Nixon; Editing by Jeffrey Hodgson)