Expressions of interest in the 107-hectare site closed last month.

The site includes the 152-year-old Georgian house once owned by motor racing enthusiast John Dawson-Damer.

A spokeswoman for the landowner, Valad Opportunity Fund No.11, said ``a number of parties'' interested in buying the property had been short-listed as part of the expressions of interest campaign that opened in July. ``We're in the process of reviewing their offers now,'' she said.

Valad bought the Cobbitty Road site in 2007 for $19million.

The NSW Heritage Branch has been considering listing Oran Park House on the State Heritage Register since 2004.

It described the property as an outstanding example of a country manor estate of the 1850s and worthy of heritage listing.

Negotiations with the Department of Planning have delayed the listing.