April 30 (Bloomberg) -- Former JPMorgan Chase & Co. executive Patrik Edsparr sued the bank for $2.3 million over an unpaid bonus, the latest dispute involving a group of senior managers who quit JPMorgan to join Citadel Investment Group LLC.

Edsparr said in a lawsuit filed in London this month that a JPMorgan U.K. unit refused to pay the deferred bonus after he left the bank for Citadel last year. Edsparr, 43, claims JPMorgan first halved, and then refused to pay an expected $5 million bonus that vested in January 2007 for payment this year.

JPMorgan, the second-biggest U.S. bank, last year sued executive search firm IDW Group over Citadel’s hiring of Edsparr and three other bank executives. It also stopped trading with Citadel for a day last year before reaching an agreement with the hedge fund over the departures.

“There is an element of turf warfare here,” said Jo Keddie, head of employment law at Dawsons LLP in London. “The people who really win are the lawyers, but if the bonus is big enough and you can afford the legal fees, it’s worth pursuing.”

Edsparr resigned in March 2008 to become global fixed- income head and European CEO of Citadel, the Chicago-based hedge-fund firm founded by Kenneth Griffin. At JPMorgan he had been on the executive committee and ran businesses including foreign exchange, securitized products and principal investments.

David Wells, a spokesman for New York-based JPMorgan, declined to comment. Roberto Moruzzi, Edsparr’s lawyer, said he couldn’t immediately comment when contacted by phone today. Edsparr didn’t immediately respond to an e-mail seeking comment.

$5 Million Reduced

JPMorgan in December sent Edsparr a letter saying that due to the performance of the business and changes in the level of the London interbank offered rate, or Libor, the expected $5 million payment had been reduced to around $2.3 million, according to the lawsuit.

On March 25, JPMorgan attorneys in New York contacted him saying they planned to pay him nothing due to “an unparticularized allegation of violation of non-solicitation agreements contained in unidentified agreements” with the bank, the filing said.

Edsparr is seeking the $2.3 million reduced payment, plus interest, the filing said. During 2008, Edsparr, Derek Kaufman, Bill King and Greg Boester joined Citadel from JPMorgan.

The case is: Edsparr v. JP Morgan, High Court of Justice, Queen’s Bench Division, HQ09X01552.

To contact the reporter on this story: James Lumley in London at jlumley1@bloomberg.net.

Last Updated: April 30, 2009 11:07 EDT