One of the major mistakes that I made was my recommending Chuck Prince, Weill told the Times, referring to his handpicked successor, who headed Citi from 2003 to 2007.
The newspaper reported that Weill and Prince are no longer on speaking terms.
Weill, who built Citi into a supermarket bank through a series of acquisitions and retired as CEO in 2003 and as chairman in 2006, said Citi's structure was not to blame for the bank's woes, saying it was management that failed, the Times reported.
Weill, 76, also told the Times he wished things had worked out better with Jamie Dimon, his former protege, who is now chief executive of JPMorgan Chase & Co
The Times said that Prince and Dimon had both declined to comment on the article.
According to the newspaper, Weill began in late 2007 to approach some Citi board members about returning to help the bank recover but was hurt when no one responded to his offer.
On December 23, Citi repaid $20 billion to the U.S. government. In 2008, Citi received $45 billion under the U.S. Troubled Asset Relief Program in two separate bailouts.
(Reporting by Phil Wahba; Editing by Steve Orlofsky)