Lehman Brothers may find itself on more secure ground, but its poor showing in the second quarter has undermined confidence in banks and brokerages and left investors wondering what to believe about the state of the credit crisis.

Lehman Brothers Holdings has pushed out its chief financial officer, Erin Callan, and chief operating officer, Joseph Gregory, amid a persistent clamor over the company's weak performance.

Officials at Lehman Brothers have held conversations about the possible sale of the firm's entire investment-management division, according to a people with knowledge of the matter.

Wall Street seemed to be preparing for a bankruptcy filing by Lehman Brothers on Sunday as a special trading session for credit default swaps was called.

Lehman Brothers, which filed for bankruptcy Sunday to became the largest casualty of the global credit crisis, is still trying to sell its asset management business, including the crown jewel, Neuberger Berman.

Lehman Brothers, which is actively shopping the entire firm, is unlikely to remain independent much longer.