Merrill logoMerrill Lynch’s losses shocked even Christopher Flowers, the private equity guru who advised Bank of America on its purchase of the Wall Street firm last fall.

“Yes, I was appalled. Yes, I was shocked,” Flowers said during a panel discussion in New York when asked about what he thought of Merrill’s losses. Merrill lost a record $15.31 billion in the fourth quarter.

Merrill agreed to be bought by BofA in a weekend deal in mid-September as the financial crisis peaked. Lehman Brothers went bankrupt the same weekend, and the U.S. government had subsequently to rescue AIG.

Flowers he got involved in the events beginning Thursday, Sept. 11 when Bank of America was looking at buying Lehman. By Friday he was looking into ways to save AIG, and then helping Bank of America buy Merrill.

“It certainly was an unusual weekend for me,” Flowers said at panel, which also had former AIG CEO Hank Greenberg and Blackstone’s Peter Peterson. “It was a busy weekend.”