Tritax Big Box agrees deal for Chesterfield unit leased by the online retail giant. : A real estate investment company has completed a deal to sell a huge warehouse in Derbyshire occupied by Amazon for almost £60 million. Tritax Big Box has sold the 500,000 sq ft unit at Chesterfield to Warehouse REIT, an investment company with a portfolio and investment strategy focused on urban warehouses. However, in 2018 it agreed an early surrender of the lease to Tesco and secured a new 15-year lease to Amazon, significantly enhancing the value of the asset.