The Office of Fair Trading (OFT) has launched an inquiry into whether the private healthcare market is "fully competitive" after receiving complaints from within the sector.
The study will analyse the nature - and limitations - of competition in the market, which is worth more than £5.5bn.
A number of private providers work under NHS contracts to offer NHS services.
The NHS currently accounts for nearly a quarter of the money paid to private healthcare providers.
The OFT study, which will begin in the spring of 2011, is likely to examine whether firms are being prevented from entering or expanding into the private healthcare market.
The review is also expected to look at how members of the public access information and how their choices are formed.
The study follows preliminary OFT research and concerns within the sector over how the market works.
Last month, it was announced that private company Circle is to take over the running of Cambridgeshire's Hinchingbrooke NHS hospital.
In September, Circle complained to the OFT about the "anti-competitive nature of the private healthcare market".
It alleges anti-competitive agreements between national private healthcare providers and private medical insurance firms.
Circle argues that such agreements act as a barrier and restrict patient choice.
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