The federal insurance fund protecting the pensions of 50 million American workers could soon find itself billions of dollars in debt and unable to meet its obligations, one of the government's top pension regulators told Congress yesterday.

James B. Lockhart, executive director of the Pension Benefit Guaranty Corp. (PBGC), told a House Ways and Means subcommittee that the looming business failures of a handful of big corporations, each with large numbers of pensioners, could so severely drain the fund that it would create a deficit of nearly $8 billion. The fund currently has a $1 billion deficit.

A sharp increase in the fund's deficit could force the agency to raise the premiums it charges companies for its pension insurance coverage. Some government officials are concerned that if the insurance premiums get too high, employers might voluntarily terminate their pension plans to escape the higher fees.

Lockhart's testimony comes a little more than a year after the Labor Department's Office of the Inspector General first warned that lax enforcement of federal pension laws could make the nation's private retirement system the next major government cleanup program, similar to the one in the savings and loan industry.

The PBGC protects an estimated $1 trillion in so-called defined-benefit private pension funds in much the same way that the Federal Deposit Insurance Corp. protects bank deposits.

Lockhart said the Bush administration may be forced to seek new legislation to give the agency additional powers over corporations to prevent companies from terminating their pension plans by filing for bankruptcy protection and then leaving the taxpayer with the pension bill.

In addition to two celebrated bankruptcy cases involving LTV Steel Co. and Eastern Air Lines, a number of other companies are "likely candidates" for bankruptcy, Lockhart warned. He would not name the companies but in an interview pointed to the airline and steel industries as areas where more bankruptcies could occur.

Ray Maria, the Labor Department's deputy inspector general, told the committee that in the 14 months since the first warnings were sounded over the issue, "We have seen only limited improvement in this effort, and systematic enforcement inadequacies remain largely unaddressed."

He said that as a result of limited government resources, fewer than 1 percent of the 900,000 private pension plans covered by the Employee Retirement Income Security Act (ERISA) "receive even passing scrutiny" from the government in any given year.

Yesterday, Lockhart rejected any comparison between the pension situation and the savings and loan industry. "The overall pension system is extremely healthy," Lockhart said after his committee appearance. "We're not an S&L crisis. I don't think we'd have to go to the taxpayer for a bailout."

Although the PBGC has a potential liability of nearly $30 billion as a result of underfunded pension plans, Lockhart said many of these funds have the financial backing of corporations in good financial condition. "The bad news is that some of the {companies whose pension funds are insured} are either in bankruptcy or are likely candidates for a filing," he said. "Some of these plans are certain to terminate in the very near future."

David G. Ball, assistant secretary of labor for pension and welfare benefits, said the Bush administration is strongly committed to pension law enforcement. Ball listed several steps the Labor Department has taken in the past year to beef up its enforcement efforts.

A lobbying group representing the pension interests of major corporations urged the committee yesterday to hold off on any new legislative proposals that might add new "costs, burdens and liabilities" to employers. David M. Davis of General Motors Corp., testifying for the group, said the vast majority of the private pension plans were well-managed and the government should get its own enforcement act together before Congress considers new legislation.