GulfMark Offshore received a merger offer from US rival Harvey Gulf International Marine just three weeks after striking a yet-to-be finalised deal to join forces with compatriot Tidewater.

GulfMark Offshore today confirmed receiving a non-binding, unsolicited proposal from Shane Guidry's Harvey Gulf to come together through a merger in which GulfMark would formally be the buyer but Harvey Gulf shareholders would come out with a majority stake in the combined entity.