*TSX gets boost from rebound in resource issues
*Heavyweight financial sector slips 1 percent
*Agrium stock rises on strong quarterly results
TORONTO, Aug 6 (Reuters) - The Toronto Stock Exchange's main index was higher on Wednesday morning as commodity-based shares bounced up after a big tumble the previous session, with quarterly results from Agrium Inc (AGU.TO) also providing a lift.
The the index's materials sector rose 3.4 percent as prices were up for gold, copper, aluminum and other commodities.
Oil and gas shares were 3.1 percent higher as the price of oil firmed to above $119 a barrel as investors awaited U.S. oil inventory data due later in the morning and following Tuesday's fall to around $118 a barrel, a three-month low.
The volatility in oil shares has helped send the TSX on its recent see-saw course, said Keith Summers, chief investment officer at Stonegate Private Counsel.
"There are opposing camps here as to who is right," he said. "There are people who think that oil is way overpriced and is going to be beaten back down to $80. There are other people who think this is a temporary selloff and it is going to go to $200."
Shortly after the open, the S&P/TSX composite index .GSPTSE was up 139.35 points, or 1.1 percent, at 13,381.55, with six of its 10 main subgroups higher.
On the downside, financials slipped 1 percent as investors moved money to energy, metals and fertilizer issues.
The benchmark index skidded nearly 2 percent on Tuesday as resource shares fell along with a wide range of commodity prices, with battered oil and gold prices setting the tone early in the day.
The market got a boost on Wednesday from Agrium, which rose C$4.14, or 5 percent, to C$86.92 after the world's third-largest nitrogen producer and the top U.S. retailer of crop supplies said its quarterly results more than doubled.
Fertilizer producer Potash Corp of Saskatchewan Inc (POT.TO) rose C$5.34, or 3 percent, to C$185.84.
Elsewhere in earnings, BCE Inc (BCE.TO), Canada's biggest telecom company, which is going private in a C$34.8-billion buyout, reported a lower quarterly profit, compared with last year's results, which included a gain from an asset sale.
BCE shares edged up 26 Canadian cents, or 0.7 percent, to C$39.42.
Shares of Heroux-Devtek Inc HRX.TO rose 49 Canadian cents, or 6.6 percent, to C$7.89 after it reported a higher first-quarter profit, helped by its aerospace and industrial segments. ($1=$1.05 Canadian) (Reporting by Jennifer Kwan; Editing by Peter Galloway)