The US Justice Department is trying to stop a big beer merger.
Budweiser brewer Anheuser-Busch InBev wants to buy the Mexican brewer Grupo Modelo, which makes Corona, for $US20.1 billion.
But the Justice Department said the two companies were responsible for about 46% of annual beer sales in the United States - too large a share for one company.
The BBC reports it has filed a lawsuit in the federal court in Washington DC to try to stop the deal, saying the merger would lead to a lack of competition that would allow beer prices to rise.
The US beer market is worth $US80 billion.