April 24 (Bloomberg) -- The Federal Reserve took on more than $74 billion in subprime mortgages, depreciating commercial leases and other assets after Bear Stearns Cos. and American International Group Inc. collapsed.

In its biggest disclosure of the securities accepted to stabilize capital markets, the Fed said yesterday it had unrealized losses of $9.6 billion on the assets as of Dec. 31. The bonds, swaps and notes were taken in from Bear Stearns, once the fifth-biggest Wall Street firm by capitalization, and AIG, which had been the world’s largest insurer.

The losses on securities backed by assets such as home loans in Florida and California signal that U.S. taxpayers may be forced to reimburse the central bank through the Troubled Asset Relief Program, according to Christopher Whalen, managing director of Torrance, California-based Institutional Risk Analytics.

Treasury spokesman Andrew Williams declined to comment.