Sweden’s Viking Supply Ships looks set to lose a charter deal in Russia agreed in February for four anchor-handling tug supply (AHTS) vessels.

The shipowner, backed by Norwegian investor Christen Sveaas, clinched the contracts for the 19,034-bhp Loke Viking (built 2010), Magne Viking, Njord Viking (both built 2011) and Brage Viking (built 2012) for 240 fixed days and up to 660 optional days.