Lettings totalled 2,385,625 sq ft, which is 76% ahead of last year's 1,354,565 sq ft.
Jules Hind, leasing and development partner at Farebrother, says that the figures for the third quarter are particularly positive.
Bolstered by five deals above the 40,000 sq ft mark, take-up totalled 820,693 sq ft, up from 444,296 sq ft last year. The lettings helped cut the availability rate from 4.9% in the second quarter to 4.1%.
"We expected there to be a demand bounce-back following the political shocks of last year, but the rate of take-up in Q3 was also 24% above the 10-year quarterly average so the market is clearly being driven by more than just the decision-making that was on hold last year," says Hind.
"Most significantly, we continue to see a succession of new types of business coming into Midtown, as illustrated by lettings this year to Saatchi, Spotify, Verizon and Framestore."
Notable deals in the third quarter included Spotify taking 104,133 sq ft at The Adelphi, Verizon taking 88,558 sq ft at MidCity Place and Metro Bank signing for 65,012 sq ft at 20 Old Bailey.
The third quarter was also more active than Q2 on the investment side. Deal volumes totalled £985m, which is well above the 10-year average of £608m.
"After an abnormally quiet second quarter of the year, Q3 activity was largely driven by three transactions: the sales of Lacon London, Aldwych House and 100 New Oxford Street, which together accounted for nearly 75% of volume," says Farebrother's head of investment Alastair Hilton.
"All three were to overseas purchasers and this underlines their continued dominance. In the round, overseas investors accounted for 86% of total turnover during the quarter."