The Justice Department on Thursday filed a lawsuit to stop Anheuser-Busch InBev's proposed $20.1 billion purchase of Mexican brewer Grupo Modelo, which would unite the ownership of popular beers like Budweiser and Corona.

The government said the deal could lead to higher beer prices in this country because it would substantially reduce competition in the U.S. beer market, particularly in 26 metropolitan areas. It said the merged firm would control nearly half the beer sales in the U.S.

In response, Anheuser-Busch InBev promised a court fight to preserve its deal.

Americans spent at least $80 billion on beer last year. ABI's Bud Light is the best-selling beer in the nation and Modelo's Corona Extra is the best-selling import.

- The Associated Press