Central office availability slumped 25% last month against a backdrop of increased take-up.
DTZ said availability in August was 10.7m sq ft, a 5% decrease on July, and 25% lower than in August 2013.
Take-up in August reached 840,000 sq ft, bringing the year-to-date total to 8.8m sq ft – 12% higher than on the same period last year.
Richard Howard, head of central London agency at DTZ, said: “The increasingly limited choice of existing offices has resulted in a number of large pre-completion lettings, the latest includes Havas’s acquisition of 158,000 sq ft at 3 Pancras Square, King’s Cross .”