AMEC will provide management and technical resources to the platform over a period of four years.
The contract, which is already underway, includes planning, cost control and implementation of safety, health, environmental and quality management systems.
The Unity platform is located in Forties field, around 5km from the Apache-operated Forties Charlie platform and 170km east of Aberdeen.
The support team will be based in Aberdeen, with 20 people working on operations on the platform.
Sandy Clark, European operations director for AMEC’s Natural Resources division, said: ‘We are delighted with this contract award from BP as we already have had a long and successful relationship with BP on the Forties Pipeline System.
‘Onshore, AMEC has supported the landline since 1995.
This additional offshore contract award enhances the strong working relationship AMEC has with BP and is recognition of our excellent safety record and 100 per cent system availability since 2001.
Having now secured the offshore element of the contract we will continue to deliver excellent service to support BP’s North Sea business.’