Alburn will have to pay £3.075m in cash two weeks after planning permission is confirmed for the site.
The net book value of the property is £656,000. Alburn is required to submit a detailed planning application by December 21.
In a statement to the stock exchange, Caffyns said it took the decision to sell the site in order to ‘reduce the company’s borrowings’.
Alburn specialises in the acquisition and redevelopment of redundant petrol stations.