WELPUT, the centralLondon specialist looked after by Schroders and Grafton Advisors, has instructed Colliers International and CBRE to sell the long leasehold interest in Stirling Square, an office development at 5-7 Carlton Gardens, SW1, for a net initial yield of 4.25%. The price reflects a capital value of £2,100 per sq ft and the building produces a rental income of circa £9.5m per snnum.