Subsea 7 has been forced to make write-downs of $657m due to the collapse of the offshore industry, figures released Wednesday show.

It said a downward revision of forecast activity levels resulted in an impairment charge of $521m relating to goodwill and $136m relating to vessels and equipment.

The provisions help push the company to a loss of $37m. However, this was an improvement on the loss of $381m seen in 2014.

Revenue