Cermaq, which already owns 17.9 percent of Copeinca, signed deals to raise its stake to over 50 percent and launched a bid on Friday for all outstanding shares to obtain a supply of food for its farmed salmon and develop its fish oil business.
Oil from fatty fish is used to feed farmed fish and as a health supplement. Fishmeal, made from fish and the bones and offal from processed fish, is also used to feed farmed fish as well as poultry, pigs and pets.
Cermaq is offering 59.70 crowns per share for all remaining stock in Copeinca, valuing the company at 3.49 billion crowns ($601.6 million), exceeding China Fishery Group's 53.85 crown bid.
It said it would finance the transaction partly through a 1.6 billion crown share issue, which it aims to complete by June.
Copeinca's Oslo-listed shares rose 3.75 percent to 62.25 crowns on Friday, indicating expectations for a higher offer than Cermaq's 59.70 crowns.
Cermaq is already assured control, however, after gaining irrevocable commitments from several shareholders, it said.
Shares in Cermaq were down 2.48 percent at 0916 GMT on the news of the planned share issue, underperforming a 0.51 percent drop in the Oslo benchmark index.
