The licences were introduced in Ireland in 2012 and under the new legal requirements auctioneers, as well as estate agents, lettings agents and management companies, now need an operating licence issued by the PSRA.
The Edinburgh auctioneers say they began the process of application in July. "Providing the PSRA with the extensive information they require has taken longer than anticipated when we first spoke to them. We have waited as long as we can, but as the deadline for producing the catalogue is now upon us, the difficult decision to postpone the sale has had to be made," said a spokesman.
The 500-lot auction is expected to raise more than €1m.
Formerly the principal seat of the Earls of Bantry, the house was owned and run by the late Egerton Shelswell-White and his wife, latterly with the help of their eldest daughter Sophie Shelswell-White, who has been general manager since 2010.
At present the auctioneers have no future date for the sale. "We apologise to all our clients who were looking forward to this historic sale, and will let you know as soon as we have any further news", they said.