Debenhams has awarded a five-year contract to BT to upgrade its data network.
The network, which transmits sales and stock order details from Debenhams' 159 stores across the UK to its head office and supply chain centres, will be up to 16 times faster.
As well as upgrading the retailer's wide area network, BT will also provide new network management tools, which will monitor systems to help ensure that links to Debenhams' tills, supply chain systems and transactional database are always running.
Steve Kircher, IT director at Debenhams, said: "It's a fundamental requirement for retailers to have IT systems that are always available - transmitting vital sales, transactions and information around the business.
"By future-proofing and closely monitoring our IT networks, Debenhams will not only be able to communicate faster and more efficiently, we will also be able to stay ahead of competition and be ready to roll out new applications in line with business requirements."