The contract will see Visa Europe migrate its transaction network onto BT's £10bn IP-based 21st Century Network (21CN), which it is still building.
The agreement will move Visa Europe onto a more efficient IP-based network, with Visa promising its 4,600 member banks in 36 countries a superior level of service, through increased support, improved business continuity and enhanced network security.
BT and Visa Europe have established a strong relationship over the past seven years, developing the processing technology to match Visa's increasingly active and expanding user base.
The latest agreement will see Visa Europe improve operations through the use of a single supplier and a flexible network making further upgrades and developments far simpler than previously possible.
Visa Europe CIO Steve Chambers said, "The trust of our customers is of paramount importance, and BT has given us the reliability, security and flexibility to successfully service our member banks and their customers going forward."