NEW YORK (Reuters) - Galleon hedge fund founder Raj Rajaratnam, accused of illegal insider trading, asked a judge on Friday to exclude from trial any evidence on more than 20 stocks newly identified by prosecutors as part of its case.

Rajaratnam was indicted on charges of trading or conspiring to trade in 12 stocks based on non-public or insider information. But prosecutors have since provided his lawyers with a list of 23 additional stocks without formally adding those to the charges.

"These new allegations effectively triple the size of this case some six months after its inception and just two months after the government represented to the Court that the parties could be ready for trial in June," Rajaratnam's lawyer, John Dowd, said in a brief to presiding US District Judge Richard Holwell.

A spokeswoman for the office of the Manhattan US Attorney declined to comment on the filing.

Rajaratnam, a Sri Lankan-born US citizen, was arrested on October 16 in an insider-trading probe that ensnared 21 traders, lawyers and executives. Holwell has scheduled on October 25 for the start of the trial of Rajaratnam, 52, and another co-defendant, former New Castle Funds LLC trader Danielle Chiesi, 44. Both Rajaratnam and Chiesi have pleaded not guilty to the charges, which include allegations that they made a total of about $49 million in illegal profits.