Raising the stakes in its long-running legal malpractice suit against Wachtell, Lipton, Rosen & Katz, CVR Energy is now alleging the elite law firm engaged in unethical billing practices by basing its legal fees on the amount charged by investment banks.

“This Kafkaesque method of billing was never disclosed to CVR and Wachtell has gone to great lengths to avoid scrutiny, by clients, the bar and the public of its billing practice,” CVR alleged in a proposed amended complaint that would seek punitive damages against the law firm.