Marine Harvest is mitigating the conditions on its takeover bid for Cermaq, despite "substantial support" from shareholders, the company said in a stock exchange release.

The bid will now only require an acceptance level of 33.4 percent from sharehoders, instead of the previously quoted 50 percent to "facilitate such a combination in the best possible way."

The tender offer is due to start on June 6 and will run to June 21. Under the bid, the company is offering 8.6 shares in Marine Harvest in addition to NOK 53.25