Slaughter and May has landed the advisory mandate as British drinks giant Diageo prepares to up its stake in India's United Spirits by a further 26%, in a deal worth £1.13bn.

Slaughters corporate and commercial partner Simon Nicholls is leading the team advising Diageo, alongside Indian law counsel Platinum Partners, which is fielding a team led by partners Nihar Mody and Yash Mohanram.

The agreement means that Diageo, which counts Johnnie Walker Scotch and Guinness among its brands, could hold up to roughly 54.8% of the Indian drinks manufacturer.

HSBC India and JM Financial acted as joint managers to the offer and joint financial advisers to Diageo, while BofA Merrill Lynch also provided financial advice to Diageo.

It is understood that United Spirits did not mandate any external legal counsel on the transaction.

Slaughters also advised Diageo on its 2012 bid to buy a 53.4% stake in the Indian company, worth £1.2bn. Its team was also headed up by Nicholls, acting opposite Herbert Smith Freehills (HSF). The latter acted for United Spirits and parent company United Breweries alongside Amarchand and local firm Kanga & Co.

The attempt culminated in a purchase of just over 25% in United Spirits last year.

Last month Slaughter and May, Addleshaw Goddard and Pinsent Masons won places as "general preferred suppliers" on Diageo's consolidated UK legal panel, following a four-month review.

The law firm trio will carry out a broad range of corporate and commercial services, while a number of specialist approved suppliers will cover areas including intellectual property, contentious work and certain commercial areas.