The sale of a property at a price agreed by the seller and the buyer or their agents.
The sale of property by private treaty is the most common method employed by estate agents and involves preparing descriptive details of the property and quoting a definitive asking price. Details can then be viewed by potential buyers and viewings arranged. 
[n] - a sale of property at a price agreed on by the seller and buyer without an intervening agency
noun a sale of property at a price agreed on by the seller and buyer without an intervening agency
a property sale based on terms resulting from a conference between buyer and seller.