* TSX closes down 0.5 percent at 12,040.01
* Nine out of 10 sectors lower
By Claire Sibonney
TORONTO, March 18 (Reuters) - Toronto's main stock market index closed moderately lower on Thursday as concerns about tighter credit in China and doubts about an aid plan for debt-stricken Greece pressured commodity prices.
Along with falling oil prices, natural gas futures also hit multi-month lows after a U.S. government report showed an unexpectedly light weekly inventory draw, sending the index's energy group down 0.9 percent.
"It seems like a very measured sort of decline," said Elvis Picardo, analyst and strategist at Global Securities in Vancouver.
"There's absolutely no sense of panic. It's comforting to see the TSX is still managing to hold above the 12,000 mark," he added. The index touched a 17-month high of 12,122.47 on Wednesday.
Gold-mining issues also declined despite flight-to-quality buying of bullion. Barrick Gold Corp (ABX.TO), the world's biggest gold producer, dropped 0.6 percent to C$40.32, while Goldcorp Inc (G.TO) fell 1.1 percent to C$39.82.
"The thing with gold is that price of gold in U.S. terms has been holding up quite all right, but in Canadian dollar terms gold prices have been slightly weak, and that's again purely because of the appreciation of the Canadian dollar," Picardo said.
The Canadian dollar fell back on Thursday after hitting a near 20-month high the day before, but continued to stalk the 99 U.S. cent mark. [CAD/]
Concern over China arose as its central bank was set to mop up a massive 213 billion yuan ($31 billion) in liquidity in open market operations this week, while a report on Thursday quoted a Greek official saying the country was not optimistic about aid from euro zone members. [ID:nTOE62H02T] [ID:nLDE62H0LL]
Another factor that may have boosted the greenback and pressured commodity prices was market speculation that the U.S. Federal Reserve may again raise its discount rate before its next meeting on April 28.
The Toronto Stock Exchange's S&P/TSX composite index .GSPTSE closed down 60.65 points, or 0.5 percent, at 12,040.01, with nine out of its 10 sectors down. Technology stocks were slightly higher.
$1=$1.01 Canadian Reporting by Claire Sibonney, editing by Peter Galloway