Coca-Cola believes it can add £3m to its £4m Glacéau Vitaminwater brand in the next few months as it gets set to launch its bestselling US flavour in the UK this month.

The vitamin-enhanced water a US brand for which Coke paid $4.1bn in 2007 has notched up rapid growth in the UK since its launch this side of the Atlantic in May 2008, to dominate the £7m functional stills market, according to Glacéau head of sales Jason Hood.

"We think that growth is going to continue," Hood said. "The brand has helped to grow the category, currently up 47%, and by the end of this year we will have grown by five times on last year. We would like that kind of growth to continue."

The new variant, XXXTriple Berry flavour, contains acai, blueberry and pomegranate, and accounts for $200m in sales in the United States. Hood predicted sales would reach $2bn by the end of 2009 in the States.

The new variant (rsp: £1.39 to £1.99) will join the six-strong Glacéau line-up in more than 6,500 retailers nationwide from the end of this month, and will be promoted through one-to-one sampling at key events, as well as experiential marketing and an interactive website.

Rival brand V Water, which was acquired by PepsiCo last April, has grown sales by 208% to £883,000 in the year to September, according to Nielsen figures.