NCP collects fines from London's congestion charge

NCP was acquired by Cinven in 2002 and has spent the past three years expanding into business such as wheel clamping and vehicle removal.

It now provides services for councils across the UK, including collecting fines from London's congestion charge.

3i is expected to keep pushing NCP, which operates 600 car parks throughout the UK, into these fast growing sectors.

Money earner

NCP boss Bob Macnaughton, who will remain in his position, said the firm saw the benefits of expanding outside of its core car parking business.

"NCP has been transformed dramatically in the past three years and we are now providing a much broader range of services to both individuals and private sector customers," he said.

Local councils have stepped up their enforcement of parking rules, targeting drivers who leave their cars illegally.

Drivers have complained that they are being unfairly fined and there have been clashes between traffic wardens and irate motorists.

One council in London, Islington, has moved to ban clamping firms from its streets after complaints from drivers.