Sri Lankan-born Rajaratnam, 53, allegedly used insider information for illegal transactions that brought him at least $45 million, government Prosecutors claim.

The federal prosecutor in New York described the case as the "the largest hedge fund insider trading case in history" and the biggest insider trading case since the 1980s, media reports say.

Rajaratnam, who is free on $100 million bail, says he is innocent. The trial is expected to last six weeks.

He faces a total of 205 years in prison and more than $100 million in fines if found guilty on the charges, which stem from transactions that occurred between 2003 and 2009.

Lloyd Blankfein, chief executive of Goldman Sachs, could be called by US prosecutors to testify, according to the Wall Street Journal. A spokesman for the bank, subject of a Galleon transaction in 2008, declined to comment Friday.

The Journal also reported that it's likely Rajaratnam would testify in his own defense a risky strategy for any defendant.

Galleon managed $3.7 billion before Rajaratnam was arrested in late 2009, and its founder was ranked by Forbes magazine in that year as the 559th wealthiest person in the world with an estimated $1.3 billion.

Rajaratnam ordered Galleon wound down after his arrest.

Prosecutors brought conspiracy and securities fraud charges from wiretaps that allegedly reveal Rajaratnam using confidential information gathered from his business relationships to pocket profits from trades involving public companies including Hilton, Google, Clearwire, and Akamai.

From the moment of his arrest, Rajaratnam has claimed his innocence, saying he would defend himself "against these accusations with the same intensity and precision" that he used on the job.

But since then, 20 of 30 people accused in civil and criminal cases related to Galleon have pleaded guilty.

The latest development, denounced by Rajaratnam's lawyers as an attack on a potential defense witness, a former head of the McKinsey consulting firm, Rajat Gupta, was targeted in a civil complaint filed March 1 by securities regulators.

Gupta, an "old friend" of Rajaratnam, was accused of giving him confidential information while Gupta was a board member at Goldman Sachs, according to the US Securities and Exchange Commission's allegations.

Rajaratnam's lawyers say the case against Gupta is a "reckless ploy for publicity" aimed at influencing the jury pool.

"There is absolutely no merit to the case against Mr Gupta. This is simply an effort to destroy a favorable witness," said John Dowd, lawyer for Rajaratnam. "These are old friends and Mr. Gupta is a distinguished human being."

Gupta, who says he's done nothing wrong, resigned last year from the board of Goldman Sachs and last week stepped down from the board of Procter and Gamble. He still sits on the board of the parent company of American Airlines, among others, and works with the Bill and Melinda Gates Foundation.

Former IBM executive Robert Moffat, who was once considered as a possible successor to CEO Samuel Palmisano, is serving a six-month prison term. He admitted that he provided confidential information to Rajaratnam's associate.

Anil Kumar, a former McKinsey executive, pleaded guilty in January and is expected to testify against Rajaratnam.