Dutch food and chemicals group DSM said on Friday it was buying Ocean Nutrition Canada, which makes ingredients for dietary supplements, in an all-cash deal for about €420 million ($534 million), including debt.

The Dutch group said Ocean Nutrition Canada's position as a leader in fish-oil derived Omega-3 fatty acids would complement DSM's vitamins and food supplements business.

DSM has sold off much of its bulk chemicals business in recent years to invest in the non-cyclical food sector to protect itself from economic downturns, buying U.S. baby foods ingredients maker Martek for $1.1 billion in February 2011.

"After our successful acquisition of Martek in 2011, the acquisition of Ocean Nutrition Canada is the logical next step in developing our nutritional lipids into a major growth platform for our nutrition cluster," DSM's chief executive, Feike Sijbesma, said in a statement.

Halifax, Nova Scotia-based Ocean Nutrition Canada is the world's biggest supplier of fish-oil derived Omega-3 fatty acids to the dietary supplement and food and beverage sectors.

It has production sites in Canada, the United States and Peru, and expects 2012 sales of about C$190 million with earnings before interest, tax, depreciation and amortisation (EBITDA) of C$55-60 million, DSM said.

The acquisition marks the third substantial deal so far this year for DSM, which has a large war chest and has been on the prowl for takeovers.

It moved into the biofuels market earlier this year announcing a 50-50 joint venture with private U.S. ethanol maker POET, one of the biggest ethanol producers in the world.

Earlier this month, DSM announced it was buying U.S. medical device-maker Kensey Nash for $360 million to strengthen its biomedical business.