Some of the most active companies traded Thursday on the Toronto Stock Exchange:

Toronto Stock Exchange (15,555.26, down 6.69 points):

Southern Pacific Resource Corp. (TSX:STP). Oil and gas. Down 3.5 cents, or 29.17 per cent, to 8.5 cents on 36.8 million shares.

Romarco Minerals Inc. (TSX:R). Miner. Down two cents, or 2.41 per cent, to 81 cents on 7.6 million shares.

Western Forest Products Inc. (TSX:WEF). Forest products. Up four cents, or 1.54 per cent, to $2.64 on 6.8 million shares.

Whitecap Resources Inc. (TSX:WCP). Oil and gas. Up $1.34, or 7.79 per cent, to $18.55 on 5.1 million shares.

Twin Butte Energy Ltd. (TSX:TBE). Oil and gas. Up four cents, or 2.14 per cent, to $1.91 on 4.8 million shares.

Mercator Minerals Ltd. (TSX:ML). Miner. Unchanged at 2.5 cents on 3.5 million shares.

Companies reporting major news:

Penn West Petroleum Ltd. (TSX:PWT) says holders of its unsecured notes have provided waivers that give the Calgary-based company until at least Oct. 14 to fix defaults arising from a previously announced restatement of its financial results. The company announced on July 29 that an internal review going back more than four years had revealed hundreds of millions in expenses had been classified incorrectly.