The sale gives Interbrew a dominant position in the UK beer industry following its purchase of leisure group Whitbread's brewing interests last month for £400m.
It also gives the Belgian brewer second place in the global brewing market.
The deal means Interbrew's stable will include Carling, Worthington Boddingtons and Wadworth 6X
Bass had hinted at the time that it wanted to offload its brewing operations to focus on its restaurant, hotel and pubs businesses, and the favoured suitor was rumoured to be Interbrew.
Bass will now concentrate on its Inter-Continental Hotels and Resorts, Crowne Plaza Hotels and Resorts, Holiday Inn and more than 3,000 British pubs and restaurants.
The deal gives Interbrew a 32% share of the UK beer market with ownership of Bass's market-leading lager Carling, Worthington bitter, Bass Ale and Caffrey's.
It also includes the joint venture with the Netherlands' Grolsch and its brewing interests in the Czech Republic, giving Interbrew a 13% share of the Czech market.
Interbrew is market leader
The Whitbread acquisition gave the company Boddingtons, Flowers, Mackeson, Murphy's and Wadworth 6X.
Interbrew sells about 120 lagers and beers, including top Western European brands Jupiler and Dommelsch, in more than 110 countries.
"It fits in with our strategy of being a world brewer with a strong local presence in our key markets," said Hugo Powell, Interbrew chief executive.
The sale marks the continued consolidation in the UK and European-wide brewing markets, which are becoming dominated by just a few players.
This has been prompted by the fact that beer consumption in traditional markets such as Germany and Denmark is stagnant.
In the UK people are also drinking less beer. Since 1984, the markets for wine and cider have been growing at beer's expense.
Bass is reportedly considering a takeover bid for its rival Whitbread, which would make it the UK's largest pub operator.