Bilfinger has sold its 62.5% stake in Bilfinger Mars Offshore, the offshore production joint venture with facilities in Poland, to German industrial holding VTC Group for an undisclosed fee.
Polish investment firm Mars retains its 37.5% share in the joint venture.
In March 2015, Bilfinger was awarded €25 million by the European Regional Development fund to build an offshore wind foundations plant in northern Poland.
"In the course of our focus on the industrial sector, activities in the area of offshore wind energy are no longer part of our core business", said Bilfinger chief financial officer Axel Salzmann. "We are therefore selling our business activities in the manufacturing and installation of offshore foundations," he added.
Bilfinger announced its intention to sell the offshore unit in February 2015, following an "unsatisfactory" financial year. The firm said the unit fell outside its "risk profile".
Dutch vessels specialist Van Oord acquired Bilfinger's installation business on 28 July.