Sweden's Stena AB has launched London arbitration over a $426m claim for a cancelled semi-submersible drilling unit.

It tore up a 2013 order for the Stena MidMax in 2017 at Samsung Heavy Industries in South Korea.

The claim also has interest added on top, but Samsung has disputed the cancellation.

Stena had said the yard was unable to complete and deliver the unit within the contractually agreed time frame.