Some 200 offshore workers with oilfield service companies Smedvig, Odfjell and Fred. Olsen Energy-owned Dolphin are threatening to walk out in a surprise dispute over the wording of an agreement already signed by the parties. In addition, Nopef is considering sympathy industrial action that may expand the possible strike to another 200 workers at other service outfits. Any work stoppage would take effect from 13 October at the earliest.