Online gambling company Partygaming has reported half-year losses of more than $47m (£23.5m) after the firm was forced to cease trading in the US.

The company, which operates the Partypoker web site, posted profits of $320m (£159m) last year before a change in US law made it illegal trade there.

The Unlawful Internet Gambling Enforcement Act criminalised the transfer and handling of payments from online gaming.

Other Partygaming operations are continuing to perform strongly, with a record number of non-US new players signed up to take its customer base to 403, 713, said the firm.

Revenue from continuing business, which takes out the effect of pulling out of the US market, has risen by 42 per cent to $212m (£105m). Shares have also increased 19 per cent to 27 pence, but are still down on the 155p shares were worth last year.

Partygaming is pinning its hopes on new bills before the US parliament, which could allow online gambling to be re-introduced, with operators licensed, regulated and taxed.