Nationwide Building Society has signed a £160m contract with BT to manage its consolidated networked IT services.
Under the seven-year outsourcing deal, Nationwide will transfer all voice and data networking infrastructure, third party network contracts and "in-scope" staff to BT.
As part of the contract, BT will deliver a service transformation programme under which it will eventually bring Nationwide's multiple networks onto its new IP-based 21CN Global network, which will support both voice and data services on a single converged platform.
BT is still building its nationwide £10bn 21st Century Network.
BT will also deliver enhanced remote access facilities to Nationwide's non-office based employees.
A new delivery model will see BT provide Nationwide cost predictability based on industry best practice and a framework of service level agreements (SLAs) at a reduced overall total cost of ownership.
Traditionally, Nationwide has developed and managed its IT operations in-house and has procured point solutions from external suppliers where necessary.
This agreement marks a shift towards a preference for a multi-sourcing model for IT services that can provide Nationwide with a reduced overall service cost and with improved service flexibility.
Peter Stafford, head of IT infrastructure at Nationwide, said, "Nationwide's growth in recent years has meant that our IT infrastructure has also had to evolve at an exponential rate to keep up with demand, and we must now seek the most efficient and scalable infrastructure service possible to support this.
"Having worked with BT for a number of years, we are very confident in the team's ability to fulfil our requirements."