The acquisition of Germany's best-known beer will boost the world's number-two brewer's international presence considerably.
In a statement, Beck's CEO Dieter Ammen said, "The quick conclusion of talks with different suitors shortened the time of uncertainty and is in the best interest of the company."
It is understood that Interbrew beat off competition from the UK's Scottish & Newcastle and Anheuser-Busch of the US to win the battle for Beck's.
It is likely that the Interbrew bid will now face fresh regulatory trouble. The Belgian brewer is already facing problems with its acquisition of Bass. Last month, it was believed to have reached a compromise that could see Interbrew sell Carling, the UK's biggest-selling lager.
Hugo Powell, CEO of Interbrew, said, "Beck's provides an excellent fit with our strategy of acquiring and developing strong brands in local markets. It is a unique premium brand, well positioned in Germany and internationally and, as such, it offers superior volume and value growth potential. We are looking forward to welcoming its management and its employees into the Interbrew family, while the operation will continue its deep-rooted and vital relationship with the city of Bremen."
Beck's joins a stable of premium beers including Stella Artois and Dos Equis of Mexico.