LONDON, July 18 (Reuters) - U.S. bank JP Morgan (JPM.N: Quote, Profile, Research) has instructed property services firm Knight Frank to offload 258,000 square feet (23,970 sq metres) of office space in London's Canary Wharf, sources familiar with the matter said on Friday.

The unfinished building at 5 Churchill Place is due for completion in July 2009 and was orginally due to be occupied by former rival Bear Stearns, which JP Morgan took over in March in a dramatic rescue operation.

A source familiar with the matter said separate plans for a new bespoke 1 million square feet (92,900 sq metres) European headquarters for JP Morgan in London's City financial district were due for submission in the autumn. (Reporting by William Kemble-Diaz; Editing by David Cowell) (See www.reutersrealestate.com for the global service for real estate professionals from Reuters).