Car park operator NCP is to change hands for the second time in three years in a deal worth £555 million.
The company, which manages more than 900 car parks and has been moving into areas such as wheel clamping and vehicle removal services, is to be bought by private equity firm 3i.
NCP has been in business for more than 70 years and has built up a portfolio that includes car parks at ten of the country's busiest airports, including Heathrow and Birmingham International.
The company also has a large number of multi-storey car parks in the West Midlands.
Private equity group Cinven bought the business for £820 million in May 2002 and then completed a sale and leaseback of more than 100 car parks - a deal that raised £600 million.
"We've almost trebled our money," said Cinven partner Jonathan Clarke. "We've overseen a period of very exciting growth and development at the business over the past three years, and we reached a point where we wondered whether we were the right shareholders to see the group into the next phase." During Cinven's ownership a major overhaul has seen NCP expand from being just an off-street parking business into one that provides a range of services for local authorities.
It issues penalty notices for London's Congestion Charge and took over operation of 25 London Underground station car parks in November 2002.
It operates or manages 230,000 parking spaces and handles more than 60 million customer transactions a year.
3i is expected to continue this expansion into new areas following the sale, which is expected to go through in the next couple of weeks.
NCP chief executive Bob Macnaughton said yesterday: "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 public sector customers."
NCP, which employs 4,000 staff in the UK, has contracts with 31 of the UK's local and regional government authorities. As a result of changes to its services, new lines of business account for more than 30 per cent of the company's earnings. 3i was one of three parties that made it through to the final stages of the auction process.
Other recent deals involving 3i have included the takeover of Interflora, and the merger of Wallace Arnold owner Coach Holiday Group and Shearings. 3i is funding the acquisition partly with the proceeds of recent property sales, while Japanese bank Mizuho was contributing debt finance.