The haul was recovered in its entirety.
Carl Rutter of Wakefield, West Yorkshire, appeared in court last week and was described by officers as "a significant conspirator".
The 46-year-old had overall possession of a number of the stolen items - now returned - which had been stored on his behalf with a view to being sold later.
He pleaded guilty at Leeds Crown Court on June 3 after being charged with conspiring to handle antiques stolen from Newby Hall and Sion Hill in North Yorkshire, as well as Firle Place in Sussex, and will be sentenced alongside Darren Webster, 45, of Leeds, West Yorkshire, and 69-year-old Brian Eaton, of Barnsley, South Yorkshire, who appeared in court in August last year charged with the same offence.
Both pleaded guilty but had been awaiting sentence subject to the outcome of Rutter's appearance.
Eaton and Webster had possession of a large number of the antiques, some stored at Eaton's home address. Webster was described by officers as the "lead conspirator", whereas Eaton was responsible for introducing prospective buyers of the antiques to Webster and Rutter.
Chippendale Table
The 14 items stolen in 2007-2009 included a George III Pembroke Chippendale drop-leaf table valued for insurance purposes at £500,000, which was made specifically for Newby Hall in 1775; a pair of Louis XVI bleu nouveau ground vases and bases with Chinese cartouches on ormolu bases with double hoof feet, known as 'The Firle Vases' (£950,000); a Sèvres blue and rose marbled ground vase Hollandois nouveau - two pieces (£180,000); and a Meissen group of the Indiscreet Harlequin modelled by J.J. Kändler (£180,000).
An ebony-veneered bracket clock by Daniel Delander of London c.1710 was taken from Sion Hill.
They were recovered by officers from the Yorkshire and Humber Regional Organised Crime Unit (ROCU) on September 22, 2011 after a year-long investigation carried out by the ROCU who received significant support from various other police forces.
A 58-year-old man from Wakefield was convicted of stealing the items in April 2011 and jailed for nine years, but refused to say where they were.
They were later recovered from Eaton's home address and Webster's address in Leeds.
