The account was previously split between several agencies, including Carat, which handled implementational planning and press buying.
TV buying and online buying, which were previously overseen by MediaVest Manchester and Latitude respectively, will also now be handled by Carat.
The review covered all media, including directories advertising, door-to-door and paid search. The pitch was overseen by the head of marketing communications, Lesley Vernon.
Non-roster agencies, including Universal McCann, MediaCom and ZenithOptimedia, also pitched for the business.
According to Nielsen Media Research, A&L spends £14 million a year on advertising. The remainder is spent on promotional activity such as online searches and inserts.
The bank last reviewed its media in 2004 and retained MediaVest Manchester, while adding Carat to the roster.
Creative duties, which are split between McCann Erickson and Big Communications, have been unaffected by the media review.
The account will move to Carat in December.