The trustee liquidating Bernard Madoff's business said on Wednesday that he had received three more bids for its market-making unit, as he prepares to sell it and distribute the proceeds to the swindler's defrauded clients.

The trustee, Irving Picard, said he expects to proceed with a court-approved auction on April 27 to sell the unit, an arm of Bernard L. Madoff Investment Securities LLC.

Madoff, who pleaded guilty in March to running a long-standing investment fraud, is in jail and awaiting sentencing in June. Prosecutors say the fraud involved as much as $65 billion in funds that clients thought they had in their Madoff accounts, but that little money is left.

Last month, the trustee announced a potential deal with Boston financial firm Castor Pollux Securities LLC to buy the trading operation for $15 million -- a fraction of what Madoff estimated it was worth a few months ago -- as long as no higher bids emerged.

Madoff's firm had a trading business and a money management business. The fraud took place in the investment unit but the entire operation has been under investigation by authorities.

Picard has said previously that one difficulty in selling the market-making unit was that it has not been operational since Madoff's December arrest and needed significant capital to restart.

The trustee said in a statement on Wednesday that the entrance of more bidders was expected to increase the sale price for the unit. No details on the bids were disclosed.

The entry of these new bidders to the process will assure that the sale price for these assets will be maximized for the benefit of Madoff's victims, he said.

Picard said he will select the entity with the highest and best bid as the winner. That bid will be presented to the U.S. Bankruptcy Court in Manhattan for approval at a hearing on April 30, which originally had been set for April 28 but was rescheduled.

Picard and his team has hired Lazard Freres & Co LLC to help sell the trading operation.

He is working with the Securities Investor Protection Corp, a brokerage-industry funded group, to recover as much of Madoff's assets as possible. Picard has said previously that he has located just more than $1 billion.

Madoff clients included affluent individuals, banks and charities. Many individual investors who gave him money to manage lost their life savings to the fraud.

(Reporting by Martha Graybow, editing by Matthew Lewis, Bernard Orr)