Five former Gen Re and AIG executives have been convicted on conspiracy charges in a US District Court.

Chief prosecutor Paul Pelletier has held out the possibility of more prosecutions over the conspiracy, which relates to a fake reinsurance arrangement that inflated AIG's loss reserves by $US500 million ($537 million) in 2000/01.

After seven days of deliberations, a federal jury found the five guilty on all charges relating to conspiracy, securities fraud, making false statements to the Securities and Exchange Commission and mail fraud.

The five defendants - former Gen Re CEO Ronald Ferguson, former Gen Re Senior VP Christopher Garand, former Gen Re Senior Counsel and VP Robert Graham, former Gen Re CFO Elizabeth Monrad and former AIG Reinsurance VP Christian Milton - are appealing the verdict, which Mr Ferguson's attorney called "a grave miscarriage of justice".

Mr Garand faces a maximum sentence of 150 years and a fine of $US29.5 million ($31.7 million), while his fellow defendants are each looking at a potential stretch of more than 200 years and a fine of $US46 million ($49.4 million).