WASHINGTON -- The federal agency that insures pensions for more than 40 million Americans last year ran the widest deficit in its 38-year history.

The Pension Benefit Guaranty Corp. says its deficit grew to $34 billion for the budget year that ended Sept. 30. That compares with a $26 billion shortfall in the previous year.

Pension obligations grew by $12 billion to $119 billion last year. Assets used to cover those obligations increased by only $4 billion to $85 billion.

The agency has now run deficits for 10 straight years. The gap has grown wider in recent years because the weak economy has triggered more corporate bankruptcies and failed pension plans.

If the trend continues, the agency could struggle to pay benefits without an infusion of taxpayer funds.