William Grant & Sons is to represent Russian Standard Vodka in the UK.
The new distribution deal is effective from January 1, 2016.
William Grant has represented Roust's Green Mark and Zubrówka brands in the UK for over two years.
Russian Standard Vodka is the best-selling premium vodka in Russia.
It launched in the UK in 2007 and now has a 12% share of the UK vodka market.
Russian Standard Vodka is owned by Roust International.
Roust distributes the William Grant & Sons portfolio in Central Europe.
Chris Mason, William Grant & Sons UK managing director, said: "Roust is one of the world's leading vodka producers and we look forward to continuing a successful partnership to achieve our ambitious goals.
"Russian Standard Vodka is an excellent fit within our existing premium portfolio, complementing our current brands.
"This partnership will ensure that William Grant & Sons UK has the strongest vodka portfolio offering with authentic brands that are differentiated within the category."
Roustam Tariko, chairman and owner of Roust, said: "Roust is delighted to consolidate our vodka portfolio in the UK with William Grant & Sons UK.
"We look forward to the continued rapid growth of Russian Standard vodka and our wider vodka portfolio here in the UK under the stewardship of the William Grants & Sons UK team.
"We believe our powerful brands in conjunction with William Grant & Sons' own strong portfolio of brands will deliver accelerated volume and market share growth in the UK."
Vodka has overtaken whisky to become the largest spirits category in the UK.
Global sales of vodka fell 5% last year, driven by a 12% fall in the Russian market.
Russian Standard Vodka had been distributed in the UK by Whyte & Mackay since 2012.
It was an official partner of the annual Edinburgh International Festival for the first time in 2015.