* TSX ends down 78.71 points, or 0.50 percent, at 15,648.40
* Half of the TSX's 10 main groups fall
* BlackBerry jumps 15.4 pct after arbitration win
By Alastair Sharp
TORONTO, April 12 (Reuters) - Canada's main stock index fell on Wednesday, as losses for its heavyweight financial and natural resource sectors offset a sharp boost in BlackBerry Ltd shares after it won an arbitration ruling against chipmaker Qualcomm Inc.
Lower oil prices pulled the index's influential energy group down 1.1 percent overall, while the financials group fell 0.8 percent, as investors took a cautious approach to lingering geopolitical tensions ahead of corporate earnings season.
Major oil sands player Canadian Natural Resources Ltd fell 1.2 percent at C$44.72.
"Earnings season is coming up fast and furious and we'll get a good idea of what companies are predicting for the rest of the year," said Barry Schwartz, portfolio manager at Baskin Financial Services.
"Corporations aren't putting money to work because they're not seeing demand like they were seeing, and of course we're very resource-heavy and prices don't dictate for anyone to start a new oil sands project here."
Cenovus Energy Inc declined 1.8 percent to C$14.45. The company's chief executive said on Tuesday that Cenovus will do more hedging after its acquisition of ConocoPhillips assets as he mounted a charm offensive on investors who balked at the deal.
Royal Bank of Canada, the country's largest lender, fell 0.8 percent to C$96.06 and Toronto-Dominion Bank lost 0.9 percent to C$65.57.
Bombardier Inc fell 6.3 percent to C$2.22 after a sharp gain in the prior session on reports its rail division is in merger talks with Siemens AG.
The Toronto Stock Exchange's S&P/TSX composite index settled down 78.71 points, or 0.50 percent, at 15,648.40, with half its 10 main groups in negative territory.
Decliners outnumbered advancers by 1.5-to-1.
BlackBerry surged 15.4 percent to C$11.85, hitting its highest level since January 2016, after Qualcomm was ordered to repay it $814.9 million in royalty payments.
Shaw Communications Inc also gained, up 4.8 percent at C$28.77 after reporting a jump in revenue driven by the addition of more wireless customers.
The Bank of Canada said it did not consider cutting interest rates as it left monetary policy unchanged amid signs of strong growth, but it is too early to conclude the economic growth is sustainable, Governor Stephen Poloz said on Wednesday.
Gold prices steadied after hitting a five-month peak in the prior session and copper fell.
The materials group, which includes precious and base metals miners and fertilizer companies, lost 0.4 percent. (Reporting by Alastair Sharp; Editing by Chizu Nomiyama)