PartyGaming, the online gaming and gambling group, has bought poker busines WPT Enterprises Inc. for a cash consideration of $12.3m, its first US acquisition since being forced out of the country in 2006.The group said the agreement will result in an ongoing revenue share relating to the purchased assets under which PartyGaming will make a minimum aggregate payment of $3m over the next three years. Subject to formal approval by the shareholders of WPT, the acquisition is expected to be completed in the fourth quarter of 2009. PartyGaming pulled out of the US in October 2006 after the Unlawful Internet Gambling Enforcement Act was passed, which banned credit-card companies from collecting payments from online gambling.In April, the group reached an agreement with the United States authorities to pay $105m, in semi-annual instalments over a period ending on 30 September 2012.The move protected the online gaming group from being prosecuted for providing internet gambling services to customers in the region.