Lehman Brothers’ headquarters in New York on Sept. 10, 2008. (Mario Tama/Getty Images)

Bloomberg | JPMorgan Chase and Citigroup helped cause the failure of Lehman Brothers by demanding more collateral and changing guarantee agreements, according to a court-ordered report on the biggest bankruptcy in U.S. history.

“The demands for collateral by Lehman’s lenders had direct impact on Lehman’s liquidity,” said Anton Valukas, the bankruptcy examiner, in a 2,200-page document filed yesterday. “Lehman’s available liquidity is central to the question of why Lehman failed.”

Valukas is chairman of Chicago law firm Jenner & Block LLP. In his report, he said that Ernst & Young LLP, Lehman’s auditing firm, failed to question inadequate disclosures by the Lehman executives.

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