* TSX up 0.56 percent, at 10,746.20
* Commodity prices support materials, oil and gas groups
* Bombardier falls 4.1 percent on canceled order (Adds details)
TORONTO, Aug 20 (Reuters) - Toronto's main stock index rose on Thursday morning, gaining support from resource-based stocks as oil and some metals prices firmed.
Oil prices tipped towards $73 a barrel, after rising more than 4 percent in the previous session, while copper and other metals gained as miner Rio Tinto issued an upbeat outlook on metals demand.
Gold was slightly lower, but shares of gold miners were higher with the rest of the TSX index's materials group, which led the index's rise with a 1.2 percent gain. Energy shares were up 0.3 percent.
Gold miner Goldcorp (G.TO) rose 1.04 percent to C$38.74, while fertilizer producer Potash Corp (POT.TO) was up 1.3 percent at C$105.80. Miner Teck Resources TCKb.TO climbed 2.3 percent to C$28.30, and oil company EnCana (ECA.TO) was up 1 percent at C$57.38.
The top heavyweight decliner was Bombardier (BBDb.TO), which fell 4.1 percent to C$3.97 after it ended a large Learjet contract with Jet Republic after the upstart private aviation company declared insolvency. [ID:nN20509344] That weighed on the index's industrials group, which slipped 0.4 percent.
The financial sector rose 0.6 percent ahead of quarterly results from Canada's big banks next week. Royal Bank of Canada (RY.TO), the index's top heavyweight advancer, was up 1.5 percent at C$51.36.
At 10:20 a.m. (1420 GMT), the S&P/TSX composite index .GSPTSE was up 59.37 points, or 0.56 percent, at 10,746.20. Six of its 10 main groups were higher.
"So far today it's kind of lackluster," said Francis Campeau, a broker at MF Global Canada in Montreal.
"China has been the underlying story. But it's been a bit of a nonevent morning...we've traded a very small range. Volume is extremely light."
The TSX has been volatile this week on seesawing appetite for risk, largely taking direction from Chinese stock markets, which havee become a barometer for confidence in the strength of the recovery.
But the TSX has also shown some resilience. On Wednesday it was able to claw back from a big drop at the open to finish in positive territory.
In the United States, the latest weekly jobless claims figures suggested a stalled job market and fanned fears that the recovery would be anemic, which initially weighed on market sentiment. [ID:nN20510281]
($1=$1.10 Canadian) (Reporting by Ka Yan Ng; editing by Peter Galloway)