New Delhi: US prosecutors may seek an 8-10 year prison term for ex-Goldman Sachs director Rajat Gupta for his conviction in insider trading but the judge could give the India-born Wall Street executive six years or less, especially in light of his "otherwise unblemished record," legal experts
said.

Gupta, 63, will be sentenced on October 24 by US district judge Jed Rakoff.

The ex-Mckinsey head is the most prominent corporate executive convicted in the US government's sweeping investigation into insider trading and his sentencing comes exactly a year after criminal charges were brought against him by India-born US Attorney in Manhattan Preet Bharara.

Federal prosecutors and Gupta's defence team are likely to file their respective memos to the judge this week in which both sides would make a case for what sentence Gupta should be given and what the judge should keep in mind in handing down the prison term.

Ahead of his sentencing, more than 200 prominent business and global leaders, including Microsoft founder Bill Gates and former UN Chief Kofi Annan, have written letters of support to Rakoff detailing Gupta's philanthropic work.

Rachel Barkow, a professor of regulatory law and policy at the New York University School of Law, said the "realistic" applicable baseline range for sentencing for Gupta would be 6-10 or 8-10 years, but Rakoff could go to the high end.

"It is not necessary to give Gupta a high sentence to serve the purpose of punishment, in light of his otherwise unblemished record," Barkow said.