Central London office take-up rose 10% in the final quarter last year, bolstered by a number of City deals.
Take-up reached 2.4m sq ft in Q4 2012, according to data from BNP Paribas Real Estate.
Excluding the City, where take-up jumped 45% to 1.4m sq ft, all London submarkets saw a decline in deals.
Key City deals during the period include Ascot Underwriting taking 29,429 sq ft on the 33rd floor of 20 Fenchurch Street, EC3.
Space signed in Q4 was up 10% on Q3, but full-year take-up in 2012 fell 11% from 2011, to 9m sq ft.
BNP PRE's managing director of central London, Dan Bayley, said: "Although there were some major deals in the last quarter across central London, the City witnessed the most significant activity, with a number of large lettings to the insurance sector. Looking ahead, we expect 2013 to be another challenging year, with transactions led mainly by lease events such as regears."