Tesoro has challenged SCF Group’s efforts to take over management of one of nine tankers purchased from the bankruptcy of fellow Russian shipowner Primorsk International Shipping.

The Texas refiner and tanker charterer alleges that SCF’s plans to take over as technical manager of the Primorsk fleet from Prisco Singapore, a sister company under the umbrella of Alexander Kirilichev’s Primorsk Shipping (Prisco), will have significant economic consequences for its charter of the 105,000-dwt Zaliv Amerika (built 2008).

SCF,