TORONTO - Some of the most active companies traded Thursday on the Toronto Stock Exchange and the TSX Venture Exchange:

Toronto Stock Exchange (11,408.32, down 351.03 points):

Viterra Inc. (TSX:VT). Grain-handler. Down three cents, or 0.19 per cent, at $16.10 on 6,444,344 shares.

Encana Corp. (TSX:ECA). Oil and gas. Down $1.74, or 7.88 per cent, at $20.39 on 5,439,197 shares. Shares were down following news the company will invest an additional $600 million this year to significantly increase production of liquids-rich natural gas. The move comes amid a prolonged downturn in the price of so-called dry gas.

Bombardier Inc. (TSX:BBD.B). Transportation equipment. Down 19 cents, or 4.71 per cent, at $3.84 on 5,296,679 shares.

Suncor Energy Inc. (TSX:SU). Oil and gas. Down $1.95, or 8.58 per cent, at $27.70 on 4,034,473 shares.

Canadian Natural Resources Ltd. (TSX:CNQ). Oil and gas. Down $1.70, or 6.01 per cent, at $26.60 on 3,544,143 shares.

Niko Resources Ltd. (TSX:NKO). Oil and gas. Down $8.32, or 38.64 per cent, at $13.21 on 3,307,603 shares.

TSX Venture Exchange (1,217.35, down 37.22 points):

PetroFrontier Corp. (TSXV:PFC). Oil and gas. Down 23 cents, or 24.21 per cent, at 72 cents on 3,839,915 shares.

Dacha Strategic Metals Inc. (TSXV:DSM). Miner. Down one cent, or 2.78 per cent, at 35 cents on 3,512,978 shares.

Companies reporting major news:

Quebecor Inc. (TSX:QBR.B). Media. Up 38 cents, or 1.06 per cent, at $36.10 on 131,237 shares. The media giant says it has won a contract to manage the advertising operations of the Montreal transit authority's network of bus shelters for 20 years. The division of media company Quebecor Inc. called the contract a "breakthrough" in a sector that is undergoing technological change. No value was provided for the deal obtained through a bidding process.

Rogers Communications Inc. (TSX:RCI.B). Telecommunications. Down 92 cents, or 2.47 per cent, at $36.30. Shares in Rogers are down despite the fact that the federal broadcast regulator approved Thursday a deal by Rogers Broadcasting Ltd. to buy the Saskatchewan Communications Network from Bluepoint Investment Inc. for $3 million. Rogers plans to relaunch the broadcaster as a Citytv station based in Regina.

Research In Motion (TSX:RIM). Consumer technology. Down 16 cents, or 1.53 per cent, at $10.33 on 970,990 shares. BlackBerry enthusiasts who favour the device's traditional physical keyboard will have to wait to get one on Research in Motion's new smartphone models. A spokeswoman for RIM has confirmed to The Canadian Press that the first BlackBerry 10 device will have touch-screen keyboards — but not physical ones.

News from © The Canadian Press, 2012