The world's biggest owner of high-end offshore support vessels faces a comprehensive financial restructuring this year as losses mount.

Norway's Solstad Offshore said its net loss in the fourth quarter was NOK 3.09bn ($355.45m), against NOK 1.29bn in 2017.

Some of this was due to a NOK 2.04bn impairment of vessel values due to significantly adjusted assumptions in its long-term forecast.