(Bloomberg) An affiliate of Ion Group, the Irish financial software behemoth whose derivatives trading arm was hacked this year, was sued by a partner for allegedly backing out of an investment agreement. Most Read from BloombergSwitzerland Blocks Sale of Leopard 1 Tanks Bound for UkrainePutin Claims He’s Back in Control. Russia’s Elite Isn’t SureQatar Group Now Confident of Winning Manchester United RaceSupreme Court Rejects Use of Race in University AdmissionsRolex and Patek Prices Fall as