03/26/2012 05:13 EDT | Updated 05/26/2012 05:12 EDT

Most actively traded companies on the TSX, TSX Venture Exchange markets

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

Toronto Stock Exchange (12,103.11, down 75.55 points):

Eastern Platinum Ltd. (TSX:ELR). Miner. Up 6.5 cents, or 19.70 per cent, at 39.5 cents on 15,575,262 shares.

Orbite Aluminae Inc. (TSX:ORT). Miner. Up 11 cents, or 4.93 per cent, at $2.34 on 9,969,935 shares.

Suncor Energy Inc. (TSX:SU). Oil and gas. Down 81 cents, or 2.59 per cent, at $30.45 on 6,093,716 shares.

Pembina Pipeline Corp. (TSX:PPL). Oil and gas. Up 75 cents, or 2.60 per cent, at $29.63 on 5,882,502 shares.

St. Augustine Gold and Copper Ltd. (TSX:SAU). Miner. Down 1.5 cents, or 5.56 per cent, at 25.5 cents on 5,423,274 shares.

Lake Shore Gold Corp. (TSX:LSG). Miner. Down two cents, or 2.06 per cent, at 95 cents on 5,158,561 shares.

TSX Venture Exchange (1,481.04, down 18.10 points):

Raging River Exploration Inc. (TSXV:RRX). Miner. Down 11 cents, or 4.85 per cent, at $2.16 on 20,887,780 shares.

Tamarack Valley Energy Ltd. (TSXV:TVE). Oil and gas. Down 7.5 cents, or 26.79 per cent, at 20.5 cents on 7,914,979 shares.

Companies reporting major news:

Canadian Pacific Railway Ltd. (TSX:CP). Railway. Down 34 cents, or 0.45 per cent, at $75 on 412,473 shares. In a letter to investors released Thursday along with a proxy circular filed with regulators, Pershing Square chief executive officer Bill Ackman outlined his view of CP — which he called the worst-performing top tier railway in North America.