Published: Jan 07, 2011 7:49 PM EST
Updated: Jan 07, 2011 4:49 PM EST

BOSTON-- The highest court in Massachusetts has ruled against U.S. Bancorp and Wells Fargo & Co. in a widely watched mortgage foreclosure case that could have serious implications for the nation's largest banks.

The Supreme Judicial Court on Friday affirmed a lower court judge's ruling invalidating two mortgage foreclosure sales because the banks did not prove that they actually owned the mortgages at the time of foreclosure.

Last fall, the banking industry's foreclosure machine came under intense scrutiny with the revelations that low-level employees called "robo signers" powered through hundreds of foreclosure affidavits a day without verifying a single sentence. At the time, analysts warned that the banks' allegedly fraudulent document procedures could imperil their ability to prove that they owned the mortgages. (Copyright 2011 by The Associated Press. All Rights Reserved.)