Ford Motor Credit Co. says it is increasing the amount it will spend to buy back secured term-loan debt from $500 million to $1 billion.

In an effort to shore up its balance sheet, Ford Motor Co. earlier this month said it was attempting to eliminate $10.4 billion in debt by offering cash and stock to debt holders.

Ford Credit says it is making the move because the initial cash tender offer has been over-subscribed.

The move has the potential to eliminate up to one-third of Ford’s outstanding debt and place it on even footing with cross-town rivals General Motors Corp. and Chrysler LLC, which are attempting to swap debt for equity under the conditions of their government-backed loans.