** Sterling Bancorp's shares plunge 18.3% after the company agrees to $261 mln sale of its banking unit, Sterling Bank
** SBT will sell the unit to Florida-based EverBank Financial Corp
** The price tag is 13% lower than SBT's market capitalization last week
** Investment management firm Bayview Acquisitions has agreed to buy the banking arm's residential tenant-in-common mortgage loans
** SBT will wind down after the deal
** Holding companies like SBT are often shuttered after they offload their banking units, which are their primary assets
** Ultimately, Sterling's board determined that there was no practical way to pursue any form of standalone independent operations - CEO Thomas O'Brien
** As of Friday, SBT had fallen marginally this year
(Reporting by Niket Nishant in Bengaluru)
((Niket.Nishant@thomsonreuters.com;))