(July 29, 2016, 9:09 AM EDT) -- BOSTON — OneBeacon American Insurance Co. and Transatlantic Reinsurance Co. jointly told a federal court in Massachusetts on July 28 that they have reached an agreement in principle regarding a reinsurance billing dispute (OneBeacon America Insurance Company v. Transatlantic Reinsurance Company, No. 14-cv-14067, D. Mass.)....