It has been bought by asset management company Aegon from property investment and development company Dunmoore.
Billingshurst Trade Park, off Stane Street, consists of 12 units let to a number of national and regional trade operators including Screwfix, Howdens, Toolstation and Easy Bathrooms.
The sale concludes the first phase of development at the business park.
The remaining phases will provide a further 250,000 sq ft of space, which includes a Lidl supermarket and a petrol filling station.
Fast food chain McDonalds has also put forward proposals to open a new 100-seater restaurant and drive-thru there.
Dunmoore chief executive Jeff Hobby said: “The sale to Aegon completes the first phase of our successful business plan from an unconsented greenfield site to a prime trade counter development.
“Along with Mansfield and Ashford, Billingshurst Trade Park is the third successful sale from our Made for Trade portfolio.
“The proceeds will be redeployed into further value-add and development opportunities within the sector.”