"Mr. Manafort is disappointed of not getting acquittals all the way through or a complete hung jury on all counts," Downing said outside the courthouse in Alexandria, Virginia.
He said Manafort thanked U.S. District Court Judge T.S. Ellis for a fair trial and the jury "for their very long and hard fought deliberations."
A jury found Manafort guilty on five counts of tax fraud, two counts of bank fraud and one count of failing to file foreign bank account reports. Ellis declared a mistrial on the 10 remaining counts for which the jurors said they had not reached a consensus.
Tuesday's verdict came after four days of deliberation, which followed a 16-day trial. It also arrived at nearly the same moment that Trump's longtime personal lawyer, Michael Cohen, pleaded guilty to tax fraud and making an excessive campaign contribution.
Manafort's trial was the first borne of charges lodged by special counsel Robert Mueller's investigation into Russian interference in the 2016 campaign. Manafort, 69, faces another federal trial in September in Washington, D.C., which also stems from the Russia probe.
— CNBC's Dan Mangan and Kevin Breuninger contributed to this report.