By Debiprasad Nayak 

MUMBAI--U.K. liquor giant Diageo PLC and its Dutch unit Relay B.V. on Tuesday made a $1.9 billion open offer to buy an additional 26% stake in India's United Spirits Ltd. from public shareholders.

Diageo is looking to buy up to 37.8 million United Spirits shares at 3,030 rupees (about $50) a share, the Indian company said in a stock-exchange filing.

If the deal is successful, Diageo's stake in United Spirits will rise to 54.78%, the filing said. Further details of the open offer will be announced on or before April 23.

Shares of United Spirits jumped 11% to 2,844.90 rupees on the news on the Bombay Stock Exchange.

Write to Debiprasad Nayak at debi.nayak@wsj.com

Subscribe to WSJ: http://online.wsj.com?mod=djnwires