The former employee is accused of forwarding confidential sales information obtained while he worked at Big Blue to HP colleagues when he joined the Californian company in 2006.

Atul Malhorta was IBM's director of global printer sales from November 1997 to April 2006 and, according to a filing at a Northern California, San Jose division court, he requested confidential sales documents concerning IBM's Global Services in March 2006 while working at the company.

These documents were marked with "IBM Confidential" on each page and, according to the court documents, an IBM Sales Co-ordinator informed Malhotra that "given the sensitive nature of the material, please do not distribute".

Malhorta joined HP in May 2006 and he is accused of sending the confidential documents in July to two HP senior Vice Presidents with the subject line "For Your Eyes Only".

HP fired Malhorta in September 2006 after only four months of employment following an internal investigation into the incident.

Emma McCullock, a spokeswoman for HP, said in a statement that the activities Malhotra is charged with were a "direct violation of clear HP policies".

"HP detected this activity, conducted an internal investigation, terminated Malhotra from his employment, and self-reported the activity to all appropriate enforcement agencies and to IBM. HP has co-operated fully with the government's investigation," she said.