The deal includes the beer brands Wainwright and Lancaster Bomber but not Thwaites’ craft brewery operation, which will continue to produce niche brands for Thwaites’ pub estate, the core of its remaining business.
Marston’s had been contract brewing for Thwaites since the Blackburn-based company announced the closure of its main brewery in the town in January 2014.
Marston’s chief executive Ralph Findlay said: “We are acquiring a very high quality business with good people and brands, and with growth potential.
“The acquisition is consistent with our beer business strategy to focus on local provenance and premium brands.”
Marston’s already owns Ringwood in Hampshire, Wychwood in Oxfordshire, Jennings in Cumbria and Banks’s in the West Midlands.