Fifth Third bank (FITB) has agreed to purchase Dallas, Texas based Comerica (CMA) for $10.9 billion, the regional banks said Monday. Pending regulatory approval, the deal would create the nation's 9th largest bank with$288 billion in assets. The all-stock transaction is aimed at helping Midwest lender Fifth Third, based in Cincinnati, compete against the nation's mega banks as it seeks to expand in the Southeast and Southwest. Comerica's stock rose 14% in early Monday trading. Its up just as much for t ...