Hines has let the top floor of its redevelopment of 280 High Holborn, WC1, to law firm Hage Aaronson at a rent of £66 per sq ft.
The company will take the 7,200 sq ft seventh floor on a 15-year lease.
It is the second letting at the 70,000 sq ft office and residential scheme to be agreed this year.
Edison Investment Research signed a lease for the 9,400 sq ft first floor at a rent of £52.50 last month.
Hines has already sold all six flats in the building at an average price of £1,400 per sq ft.
It bought the original Chichester House building in 2011 on behalf of its European Development Fund II and completed the redevelopment in late November 2012.
Alexander Knapp, director of Hines UK, said: “The top floor boasts panoramic views of the London skyline and has attracted considerable occupier interest. The range of rents from the top to the bottom of the building demonstrates the flexibility in our approach of offering terms in line with the quality of the space on offer. Negotiations with other interested parties are on-going and we are delighted that 280 High Holborn is proving to be one of the most in-demand properties in Midtown.”
Hines was advised by Jones Lang LaSalle and DTZ, with Hexell Wylie acting for Hage Aaronson.
jack.sidders@estatesgazette.com