Two former KPMG executives and an outside lawyer were found guilty by a federal jury of multiple counts of selling improper tax shelters that the government said helped wealthy clients evade tax payments.

A fourth defendant was acquitted.

Convicted were former KPMG tax partner Robert Pfaff and former senior tax manager John Larson, and Raymond Ruble, a former partner at law firm Sidley Austin. The federal court jury in New York acquitted former KPMG tax partner David Greenberg.

Mr Larson, 57, and Mr Pfaff, 58, were convicted on 12 counts of tax evasion, and Mr Ruble, 63, on 10 counts of tax evasion related to clients who evaded taxes through a vehicle known as a BLIPS tax shelter.

Prosecutors said the three men represented BLIPS as a way to eliminate capital gains or regular income of clients who had at least €13.8 million in income in a given year.

They face a maximum sentence on each count of five years in prison.

KPMG was not a defendant, agreeing in 2005 to pay €315.7 million to settle a federal probe.

The case has been watched by legal experts as its outcome has been seen as having an impact on the US government's continuing investigations into questionable tax shelters.

The defendants were charged with conspiring to evade taxes for more than 600 clients in a case that was touted as the largest criminal tax prosecution when it started in 2005 with 19 people charged with wrongdoing.

The government said the defendants helped clients evade more than €69.2 million in taxes.

But after charges were dismissed against most of the defendants, the case became much smaller.