EE is the UK’s largest mobile operator, owned by France’s Orange and Germany’s Deutsche Telekom.
BT said in a statement today: "BT and EE have signed an agreement to proceed, on an exclusive basis, to a contract for EE to provide mobile virtual network operator (MVNO) services to BT's customers and employees.”
Vodafone sources told Reuters in May that it had withdrawn from talks with BT about continuing its MVNO partnership.
Industry experts initially expected O2 to take up Vodafone’s position, as the UK operator was originally a spin-off from BT in 2002 (BT Cellnet).
However, EE has a strong list of MVNO partners and its network is used by over 25 other firms.
Financial details have not been disclosed and the contract is subject to final confirmation.