When Norwegian tech group Kongsberg agreed to buy Rolls-Royce Commercial Marine last summer, it was adamant the merger did not rely on a market recovery but was an opportunity to become the industry leader.

Now that the £500m ($655m) takeover has completed, chief ­executive Geir Haoy says Kongsberg has a lot of work to do to ­ensure the merger is as smooth as possible, but is confident it can quickly integrate the two companies to achieve its aim.