Stammers has worked at the company for 12 years managing major accounts including Tesco in the UK and Ireland, Sainsbury’s and Asda.
Andy White has been promoted to national account manager for the impulse channel and will manage accounts including Makro and Palmer & Harvey.
Mark Tinsley, regional sales director for UK & Ireland, is now also taking on the Middle East and Africa markets.
Nick Elkin has been promoted to regional sales director for western Europe, and is now responsible for Germany, Austria, Switzerland, France, Belgium, Italy and the Netherlands.
A spokeswoman said the moves were part of Gallo’s commitment to build “sustainable and mutually profitable partnerships in European markets”.