Unilever, which has more than 200 subsidiaries world wide, had more than 300 fixed line, mobile and data contracts worldwide, which are being consolidated into a single agreement with BT.
Martin Armitage, head of Unilever's Global Infrastructure Organisation (GIO), said: "The contract has two main elements - quality and benchmarking.
"BT will offer us the same or improved quality of services. We have also agreed to benchmarking to maintain our competitive position against market rates for telecoms services."
Work on the contract began in February with Armitage's team collecting an analysing data on the enormous number of telecoms and networking contracts signed by Unilever subsidiaries around the world. "It was a huge task," admitted Armitage.
The company also carried out a major benchmarking exercise on its telecoms provision. "We were already in the top quadrant, not the best but definitely not the worst," said Armitage.
Unilever issued a request for proposals in September and a team of 40 worked flat out for a month to complete the BT deal.
With telecoms companies round the world struggling with the economic downturn Armitage said: "We only went to suppliers who we were 99% certain would be around for the full length of the contract. Only the premier league providers could do the global job we need."
BT hopes the Unilever contract; its biggest outsourcing deal so far, will strengthen its global presence. BT Ignite chief executive officer Andy Green said: " This win, which incorporates around 80% of revenues driven from outside the UK, allows us to strengthen our international footprint."