On Wednesday, Norwegian natural lipid therapies manufacturer Pronova BioPharma announced receipt of a "voluntary cash offer" from German chemical company BASF.

"The intended acquisition will significantly strengthen our position in the fast growing and highly profitable market for omega-3 fatty acids," said BASF in a press release.

The offer of 12.5 Norwegian kroner ($2.18) per share works out to about $657.3 million for Pronova's shares. With the addition of the company's net debt, the total value of the deal is $846 million.

Shares of Pronova quickly rose on the news, as investors anticipated a rival bid for the company. However, Pronova's Board of Directors has already unanimously recommended that its shareholders accept BASF's bid. Moreover, shareholders controlling 60% of the company's voting shares have "irrevocably pre-accepted the offer," Pronova said in a statement.

Ninety percent of shareholders must approve the buyout in order for it to proceed. Still, assuming the deal does go through, BASF intends to integrate Pronova into its Nutrition & Health division. Pronova's marquee product  is the omega-3 heart medicine Lovaza, which GlaxoSmithKline (GSK -0.39%) markets for the company.