 NEW YORK--BUSINESS WIRE--Ambac Financial Group, Inc. NYSE:AMBC Ambac, a financial services holding company, today announced that its subsidiary, Ambac Assurance Corporation AAC, successfully completed an exchange whereby it acquired 100 of the outstanding obligations of Corolla Trust in return for AAC issued 5.1 Senior Surplus Notes SSNs. Corolla Trust was established in 2014 and is the sole owner of an AAC Junior Surplus Note JSN with a face amount of 350 million and acc 