Most actively traded companies on the TSX

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

Toronto Stock Exchange (13,552.20, up 212.46 points):

Canadian Oil Sands Ltd. (TSX:COS). Oil and gas. Up $3.41, or 55.09 per cent, to $9.60 on 29.2 million shares. Suncor Energy said it would make a hostile bid to take over Canadian Oil Sands Ltd., the largest partner in the massive Syncrude mine. Suncor is offering $4.3 billion in its own stock and would take on about $2.3 billion in COS debt, bringing the total price tag to $6.6 billion.

Rubicon Minerals Corp. (TSX:RMX). Miner. Down 33 cents, or 33 per cent, to 67 cents on 14.6 million shares.

Teck Resources Ltd. (TSX:TCK.B). Miner. Up 65 cents, or 9.64 per cent, to $7.39 on 9.8 million shares.

Suncor Energy Inc. (TSX:SU). Oil and gas. Down 77 cents, or 2.18 per cent, to $34.60 on 8.9 million shares.

First Quantum Minerals Ltd. (TSX:FM). Miner. Up 96 cents, or 18.36 per cent, to $6.19 on 8.2 million shares.

Penn West Petroleum Ltd. (TSX:PWT). Oil and gas. Up 19 cents, or 22.35 per cent, to $1.04 on 8.1 million shares.

Companies reporting major news:

Potash Corp. of Saskatchewan (TSX:POT). Fertilizer. Up 45 cents, or 1.67 per cent, to $27.42 on 3.5 million shares. Potash Corp. has withdrawn its US$8.7-billion takeover bid for salt and potash producer K+S AG, citing worsened market conditions and a lack of co-operation from the German company. K+S had rejected the proposed offer of 41 euros per share, first made at the end of May, as failing to reflect its fundamental value.