Unilever has signed a €1bn (£640m) seven-year deal for BT to develop and manage its worldwide communications infrastructure.
The move is part of the company's Path To Growth initiative to focus on its leading brands and streamline the supply chain.
BT will deliver voice, data and mobile services as well as developing new technologies on behalf of Unilever, allowing the company to reduce its current supplier base from over 200 to just one.
Martin Armitage, head of Unilever's Global Infrastructure Organisation (GIO), told vnunet.com that economies of scale achieved through the deal will help the company achieve internal cost and quality targets.
"The major benefits in price terms will come from utilising BT's network where possible," he said.
Unilever would not reveal specific project time scales and targets, but Armitage indicated that all networks should be switched to BT's or its partners' infrastructure by the end of next year.
The implementation will be done by each of Unilever's five GIO centres, which are responsible for delivering and maintaining the company's IT infrastructure for over 100,000 data users and 200,000 voice users in 180 countries.
Almost two-thirds of Unilever's data already travels over internet-based networks, and the contract will focus on the aggressive use of convergence and internet services.
But Armitage explained that the use of Voice over IP (VoIP) would be limited to small projects in a few countries. "We don't see major benefits in VoIP," he said.
BT claimed that the contract is one of the largest outsourcing deals in British corporate history.
Andy Green, chief executive at BT Ignite, the telco's services arm, said in a statement: "To be selected as Unilever's global partner is fantastic news and a real achievement.
"This hugely significant win, which incorporates around 80 per cent of revenues driven from outside the UK, allows us to strengthen our international footprint and demonstrates the value of our world class network to major players like Unilever."
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