Sony and Panasonic have had their credit ratings cut to the level of junk status for the first time.
The Fitch ratings agency pointed to their weak balance sheets and declining position in the global electronics sector, where both are struggling to compete with Samsung.
Fitch cut Sony's rating by three notches to BB- and Panasonic's by two notches to BB.
The BBC reports the rating means that the agency believes that both companies will default on their debt.
Panasonic has warned it is on track for an annual loss of almost $US10 billion, while Sony expects a small profit after four years of losses.
Earlier this month, Fitch cut Sharp's rating to junk. Standard Poor's had already done so.