The U.S. Federal Reserve has seen paper losses on real estate assets it acquired when it helped JPMorgan Chase buy Bear Stearns, the Financial Times reported.

The paper losses at a vehicle called Maiden Lane, which holds the assets, are due in part to debt used to finance large buyouts, including those of Hilton Hotels and Extended Stay, the paper said, citing unnamed sources.

The FT said losses are concentrated in Maiden Lane's commercial real estate assets, which had been marked down to $4 billion as of September.

They had a face value of $8.4 billion, with an estimated worth of $7.7 billion, when the Fed got them, it said.

Maiden Lane was formed in the second quarter of 2008, with about $28.8 billion from the New York Federal Reserve and about $1.15 billion from JPMorgan.

The portfolio had an estimated value as of March 14, 2008, of about $30 billion.