*TSX down 28.71 points at 11,601.17
*Eight of 10 sectors lower
TORONTO, July 21 (Reuters) - Toronto's main stock index was lower on Wednesday morning as a flurry of solid U.S. corporate earnings failed to ease investor nervousness that the pace of global growth is slowing.
Enthusiasm over some earnings from the U.S. financial sector and technology giant Apple Inc (AAPL.O) was tempered by caution ahead of congressional testimony on the economy by U.S. Federal Reserve Chairman Ben Bernanke later in the day.
"We've had both good and unexpectedly weak earnings from companies," said Irwin Michael, a portfolio manager at ABC Funds. "When you take it all together the market is still very thin, very volatile."
Encana Corp (ECA.TO), Canada's biggest natural gas producer, was down 2.9 percent at C$33.48 after reporting a quarterly loss, hurt partly by commodity hedging. [ID:nSGE66K0ES]
The price of oil also came off its highs and energy shares as a group dropped 0.5 percent. [O/R]
Not all U.S. quarterly results were strong. The Nasdaq fared the worst of the major indexes, weighed by shares of Gilead Sciences Inc (GILD.O), which missed expectations, and Yahoo Inc YHOO.O, which reported weak revenue. [.N]
"What we're seeing is very jerky action depending upon what news is coming over the tape or where the wind is blowing," Michael said.
Apple's rival, Research In Motion RIM.TO, sank 2.1 percent to C$56.51, pushing the Toronto index's technology sector down more than 1 percent.
Royal Bank of Canada, the country's biggest lender, was off 0.7 percent at C$53.17.
On the upside, firm copper prices helped lift the materials sector 0.5 percent, and Teck Resources TCKb.TO surged 4.5 percent to C$35.85. [MET/L]
At 10:12 a.m. (1412 GMT), the Toronto Stock Exchange's S&P/TSX composite index .GSPTSE was down 28.71 points, or 0.25 percent, at 11,601.17. Eight of its 10 main groups were lower. The consumer staples sector was up 0.2 percent.
Giant-screen movie operator IMAX Corp IMX.TO jumped more than 2 percent to C$14.26 after signing a deal to open eight theaters in China. [ID:nSGE66K0H7]
$1=$1.04 Canadian Reporting by Jennifer Kwan and Claire Sibonney; editing by Peter Galloway