Last month, a lawsuit alleged that the British bank had arranged the sale in order to make a quick profit and concealed the real value of the assets it was taking on from creditors and investors in Lehman Brothers.
But lawyers from Barclays have hit back, saying that it was public knowledge that the bank was paying under the odds for the assets in light of Lehman Brothers' bankruptcy filing, reports Bloomberg.
"The [creditors] committee merely wishes to renegotiate now a deal that it fully understood and approved of more than a year ago," its lawyers said in a court filing.
Barclays bought out Lehman's broker-dealer business last year for $1.75 billion, a deal from which it has since recorded a net gain of $4.2 billion.
The case against Barclays centres around allegations that it was given a secret $5 billion discount on the book value of securities transferred to it by executives who realised they would be working for the UK bank once the deal went through.
By Tony Aynsley