Ali Parsa, managing director of health firm Circle, said that many companies lost money after demand for the private sector to provide primary care 'never materialised as expected' under Labour.
Mr Parsa said companies could work in partnership with GP consortia that do not have the resources or capabilities to commission. There could also be opportunities for private firms to compete to provide services currently provided by PCTs, he said.
The coalition government's manifesto promised 'greater involvement of independent and voluntary providers', in the NHS. 'Health firms are likely to wait until it is clear what kind of support GPs need when they take over commissioning from PCTs,' said Mr Parsa.
'It is wrong to try and second-guess what that need is. I think we will be more cautious to only offer what GPs need in their new role,' he said.
Mr Parsa said that the private sector would be rethinking its approach after the previous wave of primary care contracts in England.
Under Labour, private firms were invited to bid for contracts to run 100 APMS health centres in the poorest areas and 150 GP-led health centres or 'Darzi' style polyclinics.
'People need to be very cautious. The market didn't value some of the partnerships that were developed as much as these companies thought. A lot of people lost a lot of resources,' said Mr Parsa.