MERGERS between large public sector bodies to save money have cost millions more to set up than forecast.

Scotland's spending watchdog said the mergers that created the Care Inspectorate, Creative Scotland, Marine Scotland and Skills Development Scotland had reported costs of £42 million so far, £12m above initial forecasts.

Audit Scotland said it was not possible to confirm the total costs and, though they had been higher than expected, the mergers had led to staff restructuring and significant reductions in staff costs.

Auditor General Robert Black criticised the mergers for lacking a clear vision when they were set up.

The watchdog's findings come ahead of the mergers of Scotland's eight police forces and the fire and rescue services into single national bodies.

They are published in a report, Learning the Lessons of Public Body mergers, which investigated nine mergers that took place between 2008 and 2011 under the Scottish Government's programme to reduce the number of national public sector bodies by 25%.

The auditors' report found that most mergers happened on time but there were gaps in the planning for the new organisations' later development.

Mr Black said: "Scotland's public sector has undergone significant reform in recent years.

"It is important that all involved with such changes learn the lessons from recent mergers."