The lawsuit, brought in the Circuit Court of Cook County, Ill., charges that several Greenberg Traurig attorneys mishandled a case against Multiut Corp., a natural gas provider, brought by Dynegy Inc., a natural gas wholesaler. The result of the underlying case was summary judgment against Multiut in 2008.

Filed on April 27, the legal malpractice lawsuit alleges that Greenberg Traurig failed to appropriately pursue counterclaims against Dynegy and did not file court papers in time. It asserts that the law firm had a conflict of interest in a separate antitrust case it filed in 2004 on Multiut’s behalf against Dynegy.