The NHS Appointments Commission, responsible for ensuring senior positions are filled fairly, has been forced to apologise for breaches of procedure over the selection of a chair for the new strategic health authority in London.

The Commissioner for Public Appointments has ruled that the key post was allocated to Dr George Greener, after the selection procedures were changed half way through the process. This, it was said, appeared to favour candidates with skills developed in the private rather than the public sectors.

An investigation also uncovered errors in record keeping, "no clear audit trail on the shortlisting process" - some of which was conducted by telephone conference - and a lack of clarity in the information sent to applicants.

The appointment will stand, but the ruling will heighten concerns that opaque procedures are being used to put candidates with significant political experience at a disadvantage.

One of the applicants was Lord Harris of Haringey, the former chair of the Metropolitan Police Authority and the Association of London Government, who was also a non-executive director of the London Ambulance Service and a director of National Association of Community Health Councils. There was widespread surprise when he failed to reach even the shortlist.

The decision to reject Lord Harris at such an early stage prompted a letter of complaint from Ken Livingstone, mayor of London, to the health secretary, Patricia Hewitt.

The NHS Appointments Commission was unavailable for comment.

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