Japanese drinks group Suntory is set to take ownership of Irish whiskey brands Kilbeggan and Tyrconnell after agreeing a deal to buy its US rival Beam.

Suntory said it plans to buy Beam, paying $13.6 billion in cash for the shares to make the Japanese company the world's third-largest maker of distilled drinks.

Including the assumption of Beam's debt, the deal is worth $16 billion and is expected to close in the second quarter.

The acquisition brings together Beam's Jim Beam and Maker's Mark bourbons, Courvoisier cognac and Sauza tequila with Suntory's Yamazaki, Hakushu, Hibiki and Kakubin Japanese whiskies, Bowmore Scotch whisky and Midori liqueur.

It will also bring the Irish whiskey brands acquired by Beam when it bought Cooley Distillery in 2012 into the Suntory fold.

Suntory will pay $83.50 per share in cash, a 25% premium to Beam's closing share price of $66.97 on Friday.

Beam's chief executive Matt Shattock and the current Beam management team will continue to lead the business from its headquarters outside Chicago, Illinois, the two companies said.

The two already had a business relationship under which Suntory distributes Beam products in Japan and Beam distributes Suntory's products in Singapore and other Asian markets.

Suntory intends to fund the acquisition through a combination of cash on hand and fully committed financing from the Bank of Tokyo-Mitsubishi UFJ.