The business was sold to a management buy-out team in 1996 for pounds 3.5m, and has now changed hands for almost four times that amount.
The deal will net a profit of pounds 1.8m for the buy-out team, led by the former managing director of BR Projects, Dick Keegan, who will make about pounds 800,000 from the takeover.
The biggest single windfall from the sale of BR Projects, now renamed Transportation Consultants International (TCI), will come to a venture capitalist, Jonathan Cohen, who backed the original buy-out through his General Practice Group. Mr Cohen's 10 per cent stake in the business is worth pounds 1.2m.
Although small compared to the windfall profits made by former BR managers from the sale of the train leasing companies, yesterday's deal may nevertheless reignite the row over the way rail privatisation shortchanged the taxpayer.
TCI has 200 employees and specialises in transport economics and planning, signal design and testing and safety and risk management.
The deal will strengthen AEA Technology's presence in the rail sector. It already owns Derby-based BR Research, which was bought in 1996, and rail now accounts for about 10 per cent of the group's pounds 300m turnover.
TCI will be integrated into AEA Technology's existing rail division, which is involved in a range of projects from the design of Virgin's new pounds 1bn fleet of tilting trains for the West Coast Main Line to an onboard computer system which is helping South West Trains improve the smoothness of journeys.
Meanwhile, the pounds 2.1bn upgrade of the West Coast Main Line is to be speeded up with the aid of state-of-the-art technology imported from the US.
The track maintenance company, Jarvis, is investing pounds 6m to bring the first high-output railway track laying machine to Britain. The machine lays new track at four times the speed of conventional methods and allows trains to run on adjacent lines while others are being renewed.