Senator Barack Obama disclosed today that Antoin Rezko was a more substantial fund-raiser for his previous campaigns than originally established.

In an interview with The Chicago Tribune today, Mr. Obama said that Mr. Rezko raised up to $250,000 for his past three political bids, about $100,000 more than initially believed.

Mr. Rezko, currently undergoing trial for fraud, is a longtime Illinois Democratic operative and Obama friend. The senator and his wife have faced questions about real estate transactions in July with Mr. Rezko, who was under grand jury investigation at the time.

The mistake was he had been a contributor and somebody involved in politics, Mr. Obama said to David Jackson about the land deal.

In an extensive interview that he hoped would quell the lingering controversy over his relationship with Rezko, Obama said that voters concerned about his judgment should view it as a mistake in not seeing the potential conflicts of interest.

But he added that voters should also see somebody who is not engaged in any wrongdoing . . . and who they can trust.