Real estate investment trust British Land is to put its Broadgate property assets in the City into a joint venture with US asset management group Blackstone Group.The real estate funds Blackstone Real Estate Partners Europe III and Blackstone Real Estate Partners VI will take a 50% stake in Broadgate valued at £1.07bn.Blackstone's share of the gross attributable value includes £987m of third party debt, representing 50% of the debt secured against the assets of Broadgate, and the net consideration paid for its 50% interest in Broadgate valued at £77 million.The Broadgate assets were valued at £2.16bn as at the end of August 2009.British Land will be the asset manager and administrator for the joint venture. Broadgate Estates Limited remains a wholly owned subsidiary of British Land and will continue to provide property management facilities and services for the occupiers of Broadgate.‘Reducing exposure to large single assets is the strategy I put in place when I arrived and this deal brings that phase to a close,’ said British Land’s chief executive, Chris Grigg.