DUBAI, Jan 19 (Reuters) - Bahrain has hired a group of banks to arrange a multi-tranche U.S. dollar-denominated bond sale, as Gulf borrowers line up to tap the market following the end-of-year lull. Bahrain hired Bank ABC, Citi, Gulf International Bank, HSBC, JPMorgan, National Bank of Bahrain and Standard Chartered to arrange investor calls starting on Tuesday, a document from one of the banks showed. An issuance comprising benchmark tranches of seven years, 12 years and/or 30 years will follow, subject to market conditions, the document said. Benchmark generally means at least $500 million. (Reporting by Yousef Saba; Editing by Alison Williams)