Fuller, Smith & Turner is paying £16m for five pubs as it moves to boost its estate in time for the Olympics.
Fuller is acquiring The Wellington at Waterloo, The Pavilion End and Bluu in the City, The Hand & Flower in Kensington Olympia and the Red Lion Hotel in Wendover, Bucks
The seller is Marston's, which is seeking cash to build new pubs in areas such as retail parks.
Fuller's managing director Simon Emeny said: "These acquisitions are high turnover managed houses with a similar trading style to our own where we feel Fuller's can add value. They emphasise our continued focus on London."
The brewer of London Pride recently lost out on a bid to buy the Capital Pub Company to rival Greene King, which paid £70 million for 34 boozers around town.