(Bloomberg) ? GNER, the British train operator owned by Sea Containers Ltd., lost a court challenge against a government decision allowing rival services on parts of its main route.

The High Court in London backed the UK rail regulator's decision authorising two train operators to run services between London and the cities of Hull and Sunderland, on England's northeast coast. GNER, which carried around 17 million passengers last year, claims the ruling is unfair and allows competitors to access the line at a fraction of its cost.

The decision comes two days after GNER's chief executive officer, Christopher Garnett, said he would step down in August after 10 years with the company. Sea Containers, based in Bermuda, is currently trying to raise cash to repay $1.2 billion in debt.

GNER holds a 10-year franchise on the East Coast Main Line between London and Scotland, one of Britain's busiest long- distance routes. The company paid the UK government 1.3 billion ($2.2 billion) to renew its service agreement last year, beating off rivals including Richard Branson's Virgin Rail Group Ltd. and FirstGroup Plc.

GNER, as the franchise operator, must pay both a variable and a fixed track access charge, in addition to its ?1.3 billion franchise fee, to operate trains on the line.