Racehorse owner the Marquesa de Moratalla is selling her 400-acre, 130-stable Childwick Bury Stud, in St Albans, Herts.
She cites age as the reason behind her decision to downsize her breeding operation, which produced Tin Horse, the French 2000 Guineas winner.
She is also considering selling some of her mares at Deauville in December.
The asking price for the stud is £9.5m.
Tel: Bidwells on 01223 559352.
This news story was first published in the current issue of Horse & Hound (1 September, 2011)