Kristian Siem-backed Siem Offshore is seeking more time from bondholders to allow the company to clinch a long-term restructuring of its $1bn debt pile.

The Oslo-listed offshore support vessel owner has called a meeting of noteholders to approve a waiver of financial covenants up to 31 December.

In June, it won a waiver until 30 October, but has now admitted it is unlikely to reach a final refinancing agreement by then.