NEW YORK — Global liquor behemoth Diageo said Wednesday it will pay up to $1 billion to buy a tequila brand co-founded by movie star George Clooney.

Clooney founded the Casamigos brand four years ago with partners Rande Gerber and Mike Meldma.

Diageo said it will pay $700 million for Casamigos at first, and another $300 million over 10 years if the brand reaches certain performance milestones.

London-based Diageo’s other brands include Johnnie Walker, Guinness and Captain Morgan.

Clooney and Gerber, an entrepreneur who is married to model Cindy Crawford, have appeared in ads for the brand.