Benchmarking levels for public private partnership (PPP) projects should not be made publicly available as it would hand contractors a competitive edge and diminish the State's ability to achieve best value for money, an Oireachtas Committee has been told.

Releasing ballpark budgets for PPP understakings into the public domain would encourage companies tendering for contracts to pitch prices close to those envisaged by departments, reducing the potential for gaining good value for tax payers, said Mr Eamon Kearns, director of the Department of Finance's PPP unit.

If the experiences of countries with a longer track record in PPPs is any guide, then it is best to keep benchmarks under wraps when tenders are being sought, Mr Kearns told the Oireachtas Joint Committee on Finance and the Public Service.

Public private partnerships offer many benefits he added; including accelerated delivery of infrastructure projects, transfer of risk away from the State to private firms best placed to manage them, a cross pollination of skills between the public and private sectors and increased value for money over the lifetime of long-term projects.

It is the Department of Finance's intention to establish a database of costs for different types of PPP projects over time. With the concept still relatively new to the State, it will take time for such a cost structure to emerge however, said Mr Kearns.

Fine Gael finance spokesman Mr Richard Bruton questioned whether PPPs made sound economic sense as Government can avail of cheaper credit to fund projects than from the private sector.