Sonnenschein Nath & Rosenthal has filed a petition for certiorari with the Supreme Court, asking the justices to weigh in on a breach of contract dispute between the firm and a former partner.

The petition stems from a 2005 suit filed by Douglas Rosenthal, a former antitrust partner at Sonnenschein, alleging that he was not fairly compensated for representing the families of those killed in the 1988 bombing of Pan Am Flight 103 over Lockerbie, Scotland. That contingency work made $18 million for Sonnenschein. Rosenthal also claimed he was owed origination credit for Sonnenschein’s representation of Sun Microsystems against Microsoft Corp. That work generated $20 million for the firm.