* Deal highlights tequila's long-term prospects
* Comes months after deal for George Clooney's brand
* Bacardi has owned Patron stake since 2008 (Adds details, background, bylines, bullet points)
Jan 22 (Reuters) - Bacardi has agreed to buy out Patron Spirits International in a deal valuing the top high-end tequila maker at $5.1 billion, highlighting the appetite big drinks groups have for the Mexican spirit.
The deal comes five months after Diageo bought George Clooney's Casamigos tequila for up to $1 billion.
Tequila sales, still largely confined to North America, are growing faster than the overall alcoholic drinks market as high-end brands help tequila shrug off its image as a party drink.
Patron, founded more than 25 years ago, was a high-end pioneer, but now competes with a range of brands such as Diageo's Don Julio, Pernod Ricard's Avion and Brown-Forman's Herradura.
Global tequila sales rose 5.2 percent in 2016, according to research firm IWSR, while the overall market for alcoholic drinks fell 1.3 percent.
Premium brands are outselling mass-market labels, as consumers increasingly look to "trade up" to more expensive drinks.
Bermuda-based Bacardi was founded in Cuba in 1862, selling its namesake rum. It now owns some 200 brands including Bombay Sapphire gin and Grey Goose vodka. It has owned a minority stake in Patron since 2008.
The acquisition marks the first major deal under Bacardi's Mahesh Madhavan, who was appointed chief executive in October. It is expected to close in the first half of 2018. (Reporting by Martinne Geller in London and Uday Sampath in Bengaluru; editing by Sai Sachin Ravikumar and Jason Neely)