The authority at Macclesfield, Cheshire, paid in effect just over pounds 1.5m for West Peaks Hospital, a 42-bed unit with two operating theatres. It would have cost the authority pounds 7m to build.
The hospital, which opened last October, was built on the same site as Macclesfield District General Hospital. The health authority sold the land two years earlier - when land prices were considerably higher than today - for pounds 675,000.
Last week the authority signed a contract with the owner, Hospital Corporation International, to pay pounds 2.2m for West Peaks. It was valued at pounds 2.6m but the authority is writing off pounds 400,000 which the corporation had guaranteed to pay over two years for services such as pathology and X-rays.
Macclesfield has used its windfall to bring forward the opening of a new maternity unit, which would still have been years away had it been necessary to seek new government funding.
The district hospital's orthopaedic unit will move into West Peaks, which will be converted to a 56-bed wing by next March. The maternity wards will then transfer into what was the orthopaedic section.
Private health care industry analysts maintain that the sale is merely the result of local over-capacity. But Peter Hayes, the authority chairman, said it was also the result of Macclesfield's success in cutting waiting lists, which had reduced demand for private health care. No one was waiting more than a year for surgery, he said.
Hospital Corporation International acquired West Peaks in February following a merger with the original owner, Bioplan, and immediately began reviewing its assets.