A wealthy client of the Swiss bank UBS pleaded guilty on Monday to tax fraud, the ninth American caught up in an investigation of the bank's offshore private banking services. The bank client, Harry Abrahamsen of Oradell, N.J., pleaded guilty in U.S. District Court in Newark to one count of failing to file proper disclosures on his UBS offshore accounts with the Internal Revenue Service, according to court papers filed in the case. Abrahamsen used a sham offshore corporation in Panama known as Primrose Properties SA to help hide his UBS accounts, according to court papers. Prosecutors charged him with failing to file disclosures to the IRS in 2005. He also failed to disclose his UBS account and an account he had opened for his daughter, the court files said. The charges against Abrahamsen show how federal prosecutors are increasingly untangling the web of offshore entities used by UBS and other banks to hide client money in tax havens like Hong Kong, Liechtenstein, Singapore and Panama. Abrahamsen started his Panamanian corporation in 2000 and the UBS accounts in 2002. He financed his UBS accounts, court papers said, by false claiming $1.3 million in inflated expenses that he said had been paid to a Swiss company by his printing business, SJT Imaging Inc. The inflated expenses were then illegally deducted from SJT Imaging's tax returns, and the money gained from that allowed Abrahamsen to fund his UBS accounts. The Swiss government is trying to find a way to diffuse a growing legal and diplomatic feud with the United States over a deal it reached in August. Under that deal, Switzerland has until Aug. 19 to transfer the names and details of 4,450 American clients of UBS to the IRS or the bank could face criminal sanctions. In February 2009, UBS paid a $780 million fine and admitted criminal wrongdoing in connection with offshore tax evasion services sold to wealthy Americans through its private bank. 