(Bloomberg News) Lehman Brothers Holdings Inc. is claiming $500 million from Barclays Plc for allegedly failing to pay all of the bonuses the U.K. bank agreed to when it bought the defunct investment firm's North American business.

Lehman wrote a letter to U.S. Bankruptcy Judge James Peck saying an opinion he wrote in February showed that Barclays "breached its bonus payment obligations." The letter was filed in U.S. Bankruptcy Court in Manhattan on April 29.

Barclays has said it paid the full $2 billion it promised, including non-bonus compensation. Peck issued the February opinion in a lawsuit that Lehman lost seeking $11 billion from Barclays over the deal.

Peck's ruling, which followed a trial with more than 30 days of testimony, exonerated Barclays from having contrived to make a "windfall" on the purchase as Lehman alleged. The ruling left the two sides still fighting over what is owed to whom.

Separately, the trustee for Lehman's brokerage is in a dispute with Barclays over $3.5 billion in assets after Peck failed to specify how much Barclays was entitled to when it bought the North American business in September 2008.

Michael O'Looney, a spokesman for London-based Barclays, didn't immediately respond to an e-mail seeking comment.

The case is In re Lehman Brothers Holdings Inc., 08-13555, U.S. Bankruptcy Court, Southern District of New York (Manhattan).