EXHIBIT 21 SUBSIDIARIES OF UST CORP.(*) USTrust United States Trust Company UST Bank/Connecticut JSA Financial Corporation UST Leasing Corporation(**) UST Securities Corp.(**) UST Capital Corp.(***) (*) Other than UST Bank/Connecticut which is a Connecticut trust company, each of the above subsidiaries of UST Corp. is a Massachusetts Corporation or trust company and each of the above entities does business only under its corporate name. The foregoing list does not include the names of inactive subsidiaries or the names of subsidiaries of banking entities which subsidiaries have been organized to hold foreclosed property, or other assets held in satisfaction of debts previously contracted by the applicable banking entity. (**) Wholly-owned by USTrust (***) Wholly-owned by United States Trust Company