Renowned bookmaker, William Hill, has moved more of its operations to
Gibraltar, where bosses say there is less risk of continued undercutting by foreign betting operations.
Chief executive Ralph Topping said the favourable rates and betting laws in the offshore jurisdiction would help relieve the pressure it is suffering from foreign-based rivals and betting exchanges such as Betfair.
He issued a warning to government legislators that more British jobs in the betting industry would be at risk if they did not ensure a level playing field.
"Betting exchanges – and particularly Betfair as the dominant market player – have fundamentally changed the structure of the UK betting market with little reaction from government or other agencies," he said.
"This has been exacerbated by competition from offshore telephone operators and the previous government's inertia over the issue of creating a level tax and regulatory playing field."
Companies that operate internet services offshore generally pay up to two per cent tax on their profits and do not face the horserace betting levy which bookies in the UK must pay to take bets on British races.
William Hill was followed to the Iberian outpost by competitors, Ladbrokes, which moved its internet sportsbook operation there last year and also moved its Aintree-based call centre offshore as well.