John Fredriksen is betting big on a recovery in the offshore drilling sector with a major investment in the world's largest contractor, Valaris.

The shipping tycoon's Cyprus-based Famatown Finance, part of the Seatankers Group, has acquired a 5% stake in the New York-listed owner of 13 drillships and 44 jack-up rigs.

The open-market deals give Fredriksen a holding worth $115m.