Norway's Siem Offshore has disposed of two vessels to reduce debt further following its $1bn refinancing completed in May.

The Oslo-listed company said the 26,670-bhp anchor-handling tug supply vessels Siem Garnet and Siem Diamond (both built 2010) have gone to an independent third party for further trading outside the offshore shipping industry.

The sale was done on market terms and at book values, the offshore vessel owner added.