France's Loire, Rhône and Midi wines.
Mistral will be integrated into Berry Bros's agency arm, Fields, Morris & Verdin, which supplies the London on-trade and wine merchants throughout the UK.
The acquisition will see Mistral exclusives Château de Beaucastel and Perrin et Fils become part of FMV's portfolio, which currently includes Vega Sicilia, Champagne Jacquesson and Dog Point Vineyard.
FMV managing director John Hutton said the move "not only strengthens the FMV agency portfolio but also offers us the opportunity to grow our business in new markets".
Berry Bros's Good Ordinary Claret - its best-selling wine since its introduction in 1974 - is to be sourced from a new supplier and from a single vintage. The 2005 vintage wine will be sourced from Bordeaux négociant Dourthe and will increase in price to £7.20 a bottle, a rise of £1.70. The new wine will be a "discernible step up in quality from the previous wine" according to Berry Bros. It is available this month.