A US judge has overturned half of former Ukrainian Prime Minister Pavlo Lazarenko's convictions for money laundering and extortion.
Lazarenko is under house arrest in San Francisco
However, he rejected requests by Lazarenko's lawyers for a new trial.
Lazarenko, who was convicted last June, claims the deals that allowed him to become a multimillionaire while in power in the Ukraine were legitimate.
He was the first former head of government to be tried in the US since Panama's Manuel Noriega in 1992.
"It's a tremendous victory," said Lazarenko's lawyer, Daniel Horowitz, pointing out that the total amount of money in question had been reduced from $280m (£153m) to less than $10m.
"Half of the counts have been knocked out and we haven't even gotten to the Court of Appeal yet," said Mr Horowitz, who argues that political rivals plotted to withhold evidence that could have cleared his client.
But a spokesman for the prosecution said the most serious charges remained and Lazarenko faced "significant time in jail".
In June 2004, the former Ukrainian premier was found guilty of 29 counts, including money laundering, fraud and transportation of stolen property dating back to his time in office, 1996-1997.
Of those convictions, 15 counts were thrown out by a US district judge in San Francisco on Friday.
Several companies and banks based in countries including Ukraine, Poland, Hungary, the Netherlands, Switzerland and the US are involved in the case.
Lazarenko, who sought political asylum in the US in 1999 claiming he had faced assassination attempts, is currently under house arrest in San Francisco.
His sentence is due to be handed down on 23 June.