The 50:50 joint venture between British Land and Oxford Properties has reached an agreement with insurance giant Aon for a pre-letting of 18,000 m2 at the Leadenhall tower in London. The letting represents one-third of the 56,700 m2 office tower which is under construction for delivery in mid-2014.

Aon will occupy the lower 10 floors of the 47-storey building for an average lease term of 19 years to first break. Aon will also have options to take up further space totalling up to 85,000 sq ft on levels 14-18.

Including Aon, over 50% of British Land's total £1.1 bn London office development programme and 62% of its City developments have now been pre-let in advance of completion between the end of 2012 and 2014.

Aon was advised by CBRE and British Land and Oxford Properties were advised by DTZ and Jones Lang LaSalle.

The leasing deal comes four months after the joint venture appointed Laing O’Rourke as main contractor for the scheme. Construction is under way and on schedule.

Oxford invests in and manages real estate assets on behalf of the EUR 40 bn Canadian pension fund OMERS.