Online betting companies are pulling out of the United States (US) following the passage of prohibitive legislation.

The US House of Representatives approved the Unlawful Gaming Enforcement Act, prohibiting banks and credit card operators to process online gaming payments in the US. The legislation will pass to the US Senate for debate.

Following the weekend’s vote, which caused online gambling shares to plunge Monday, operators PartyGaming and 888 Holdings said they were suspending online betting operations in the US once President George Bush ratifies the new law.

Fellow operator, Sportingbet, which makes about 70% of its revenue in the US, suggested it might continue its business there, potentially using offshore banks to make transactions.

But Sportingbet and 888 have said that they are currently looking into whether the new US legislation contravened commitments made by the country to the World Trade Organisation (WTO).

The WTO ruled that the US laws concerning internet gaming was in breach of its rules last year.

Nigel Payne, Sportingbet’s told BBC Radio 4 the UK government, along with the European Union, had been “disappointingly silent”, accusing the US of protectionism.