The Scottish Government is to formally consult on extending the legislation, which already applies to public authorities.

Organisations that would be affected are the firms running Addiewell and Kilmarnock prisons and those which build and maintain schools and hospitals.

The law may also be extended to include the Association of Chief Police Officers in Scotland, Glasgow Housing Association, trusts set up by local councils to provide leisure, sport or cultural services and the firms which operate and maintain trunk roads.

But CBI Scotland has claimed that extending freedom of information to private firms providing public services is unnecessary and will raise the cost of services.

Parliamentary Business Minister Bruce Crawford said: “It is important that organisations who deliver key public services for the people of Scotland operate transparently so the public can be reassured we are getting high-quality services and value for money.”

He said he was sympathetic to the idea that people should be able to follow how public money was being spent through access to information about PFI/PPP contracts.

Current legislation provides a statutory right of access to information held by about 10,000 Scottish public authorities.

Mr Crawford said the Government will carry out its consultation at the 2009 Holyrood Freedom Of Information Conference in Edinburgh.

He said: “The Scottish Government is committed to the principles that underpin freedom of information legislation.

“These principles of openness and transparency are essential parts of open democratic government.”

He added that responses to a discussion paper examining the options for extending the legislation had backed the principle of greater openness and said: “I now intend to formally consult with a range of organisations about whether it is appropriate for them to be covered by FOI.”

The minister also pledged the consultation would consider the possible costs of extending freedom of information laws.

He said the global recession meant parts of the economy were “under particular strain”, and added: “A key part of the consultation will be our examination of the costs and burdens associated with any extension of coverage and any risks to business efficiency and competitiveness that flow from that.”

Mr Crawford said: “We will listen to organisations who raise concerns about being able to meet the requirements of FOI.”

However David Lonsdale, assistant director of CBI Scotland, argued: “Extending FoI obligations to include businesses which supply public services - when the public authorities who commission the service are themselves already subject to FoI is unnecessary, will raise the cost of public services and could deter potential suppliers from contracting with government.

“It would also fly in the face of the recent encouraging steps the current Scottish Government has taken to simplify regulation and public procurement.”