Three big corporate pre-lettings accounted for the strong performance over the quarter, with Barclays Bank 650,000 sf at Canary Wharf; Standard Chartered Bank taking 250,000 sf at Standard Life's 10 Gresham Street, EC2 and Accenture taking 350,000 sf in Plantation Place, EC3. DTZ calculated that seven major pre-lettings totalling 1.4 million sf went under offer during September alone.

But despite the strong letting activity, availability is still increasing. Available floorspace now stands at 10.2 million sf--or 5.2% of stock-- compared with a low point four million sf in September 2000.

Jonathan Evans, DTZ's Head of West End Agency said: 'The Central London office market is being increasingly affected by the growing uncertainty in the business climate, which is being symptomised by growing availability. On the other hand, letting activity has so far held up comparatively well. Speculative supply is, and will remain, limited. The main question that remains is whether the so far robust level of demand can be sustained into the future.'