Sullivan & Cromwell and Cooley are advising drinks giant Diageo on its $550m (£426m) sale of a portfolio of brands to US spirits company Sazerac.

Diageo will sell 19 of its brands in the deal, including Romana Sambuca, Seagram's Canadian whiskey and the recently discontinued UK gin brand Booth's.

Longstanding Diageo adviser Sullivan is advising the UK-headquartered company, with its team led by New York M&A partner Melissa Sawyer and including tax partner Ron Creamer, competition partner Steve Holley and EU competition group head Juan Rodriguez.

London-based Rodriguez advised Diageo on its acquisition of the tequila company set up by US actor George Clooney last year.

Fellow US firm Cooley is advising New Orleans-based spirits company Sazerac, with its team including California corporate partners Jason Kent and Ben Beerle.

The deal is expected to close in early 2019 subject to regulatory approval, and will net Diageo shareholders £340m after tax and transaction costs.

Diageo, which owns brands including Guinness, Smirnoff vodka and Johnnie Walker whisky, has a longstanding relationship with Sullivan. The firm advised on the company's £456.5m joint venture with Dutch distiller Ketel One in 2008, and a US regulatory investigation in 2011 that settled for £13m.

Diageo has also used magic circle firm Slaughter and May for a series of cross-border M&A deals with Dutch brewing company Heineken.