BT, the UK's leading fixed line phone operator, has won two contracts for the National Health Service worth around £1.6bn ($2.77bn) over 10 years.
BT's deal is a key step to NHS reform, says the government
The group saw off rival bids from IBM for the contracts to upgrade NHS computer networks across the UK.
BT said the deal would allow it to pick up around £50m of new revenues this year and upwards of £15m next year.
Meanwhile, management consultancy giant Accenture has been awarded a 10-year NHS contract, worth just over £1bn.
BT chief executive Ben Verwaayen said: "These wins are BT's biggest ever, and evidence of the new face of BT truly emerging."
He added: "I think these are state-of-the-art type of contracts and BT being able to win...is a sign of confidence that the transformation of BT is on track."
The company said the deal to provide services for the key London region was worth £996m over 10 years.
Meanwhile BT's second contract to design, deliver and manage a national patient-record database and messaging service, was worth £620m over the same period.
Accenture said it will oversee the project to provide a computerised system that manages patient information, appointments and prescriptions in the North East of England.
Health Secretary John Reid said the move was the latest step in the reform of NHS services, which aims to connect more than 30,000 GPs and 270 acute, community and mental NHS Trusts in a single national system.
By 2010, the NHS Care Records scheme aims to have an electronic NHS Care Record for every NHS patient in England.
The record will detail the key treatments and care given to each of the NHS's 50 million patients.
Dr Reid added: "Patient records will be available 24 hours a day, seven days a week to ensure that vital information about an individual's health care and history can be available to health professionals."
He added it would cut down on time wasted by NHS staff and patients as paper records are traced.