Hanover was selected following a competitive six-way pitch process, which included the incumbent. The account is understood to be worth about £150,000 in fees annually.
The agency will help lobby the Government to encourage the consumption of beer in the supervised environment of pubs, and highlight the industry's importance to the economy.
BBPA CEO Brigid Simmonds said: 'We will be working together to encourage the Government to lighten the regulatory and tax load that burdens the sector and is a brake on growth.'