The deal paves the way for construction to start on the £340m iconic building.
Big name contractors Balfour Beatty, Bovis Lend Lease, Laing O’Rourke, Mace, Skanska and Sir Robert McAlpine are currently bidding the job and awaiting news in the New Year of which firm has been successful.
Bovis Lend Lease was in line for the contract three years ago when the 47-storey office project stalled in the office market downturn.
The 224m high Leadenhall Building will be one of the tallest buildings in the Square Mile.
Detailed planning consent is in place and demolition and preliminary basement works have already been completed, with practical completion to shell and core scheduled for mid 2014.
British Land and Oxford will combine their significant real estate experience to co-develop Leadenhall, with British Land acting as lead development manager.
British Land has contributed the site at an effective land value of £90m and Oxford will contribute the next £90m in cash for the costs of preparing and commencing the development.
British Land’s contribution in addition to the land will be around £125m.