Telenor, the Norwegian telecoms company, has claimed a victory in its long-running battle with Alfa, its Russian business partner, after a US court ruled in Telenor’s favour in a dispute over their joint-ownership of Kyivstar, Ukraine’s largest mobile phone company.

An arbitration tribunal in New York on Thursday gave Alfa 120 days to abide by an agreement that forces Alfa either to sell its stake in Kyivstar or reduce its holdings in two Ukrainian competitors to below 5 per cent.