The chief executive of Treasury Wine Estates has promised the high quality of the wines produced by luxury chardonnay maker Frank Family Vineyards in the Napa Valley in California will be maintained as it looks to step up volumes after a $US315 million ($434 million) acquisition.

Tim Ford said the quality would not be diminished as it sourced extra grapes from its own vineyards in California and contracted growers to expand the volumes of the No.2 player in the luxury chardonnay market in the United States.