Rolls-Royce (LON:RR) shares sunk slightly in early trading on Friday, after the group announced that it had agreed to sell its loss-making commercial marine business to Norway’s Kongsberg for an enterprise value of £500 million.

Net proceeds are expected to be between £350 million and £400 million, after taking pension liabilities and other costs into account. The move comes as part of a wide-ranging restructuring plan for Rolls-Royce, which aims to save £400 million a year.

The business has about 3,600 employees, mainly based in the Nordic region, and the sale includes propulsion, deck machinery, automation and control, a service network spanning more than 30 countries and ship design capability.

“This transaction builds on the actions we have taken over the last two years to simplify our business,” Rolls-Royce chief executive Warren East said.

“The sale of our commercial marine business will enable us to focus on our three core businesses and on meeting the vital power needs of our customers.”

Shares in Rolls-Royce (LON:RR) are currently trading down 0.53 percent at 980.00 (0925GMT).