A private health firm has won a £5m contract to run GP services in London - one of the first of an wave of deals expected to be given the go-ahead.
The government wants to see a range of GP providers
Care UK beat four rivals to run a practice and walk-in centre in Barking and Dagenham, east London.
The services will be free to NHS patients and see the return of Saturday morning surgery.
The deal has been signed by local NHS chiefs, but brokered by the government as part of an overhaul of services.
Last year, ministers announced they wanted to see a range of providers running community NHS services.
Many predicted the move would lead to the opening up of the GP market to private firms.
To date, much of the private involvement in the NHS has been confined to the hospital market.
United Health Europe, part of a US firm, was chosen as preferred bidder to run services in Derbyshire at the beginning of this year, but the contract has been held up by a legal challenge by a local resident.
Similar deals are thought to be close to being signed elsewhere in the country.
Care UK, which was set up in 1994, mainly runs care homes and private hospitals.
Under the terms of the three-year contract, the company will provide GP services for 7,000 patients and employ 3 doctors and 7 nurses.
The walk-in centre is likely to handle about 100 patients a day.
The government agreed to help the local primary care trusts - one of a number of groups it is lending support to - as the area has traditionally struggled to attract doctors.
Paul Sinden, from Barking and Dagenham PCT, said the area had been under doctored for some time and the new arrangement would provide "additional access to GP and extended primary care through the walk-in centre".
And Mike Parish, chief executive of Care UK, added: "We bring a wealth of experience in operating community-based health and social care services to the project."
But Dr Laurence Buckman, of the British Medical Association's GPs committee, questioned whether offering contracts to private firms was the best way of providing care.
"Family doctors are in the business of providing high quality care for their patients rather than operating in a market place which may not always be driven by patients' needs."