Justices to Rule on Peril to Pensions : Benefits: A federal agency seeks authority to order employers to restore terminated plans.

The Supreme Court today agreed to review a ruling that government lawyers say threatens the federal program protecting the pensions of 30 million American workers.

The justices said they will decide what authority the Pension Benefit Guaranty Corp., a federal agency, has to order employers to restore terminated pension plans.

A federal appeals court limited such authority by setting aside the agency’s order that LTV Corp. and its subsidiary, LTV Steel Co., restore three pension plans with unfunded liabilities of $2.3 billion.

The appeal acted on today said the ruling, if not overturned, could make the agency “an open-ended source of industry bailouts” and “could lead to a financial crisis similar to that currently facing” the government’s insurance program for the savings and loan industry.

The Pension Benefit Guaranty Corp., modeled after the Federal Deposit Insurance Corp. and the Federal Savings and Loan Insurance Corp., is wholly owned by the federal government. Its board of directors is composed of the secretaries of labor, treasury and commerce.

The agency protects the pension benefits of the 30 million Americans who participate in single-employer defined benefit pension plans.

When a pension plan is ended with insufficient money to satisfy promised benefits, the federal agency becomes the pension plan’s trustee, taking over its assets and liabilities. The agency then pays all benefits workers had earned as of the date the pension plan ended.

In fiscal year 1988, the Pension Benefit Guaranty Corp. paid $324.7 million in insured benefits to 113,000 retirees who participated in 1,476 terminated pension plans.

The cost of the pension insurance is paid primarily by employers with active pension plans, and by employers who terminate under-funded pension plans.

The agency has money problems of its own. In its most recent annual report, the PBGC listed liabilities of $4 billion and assets of $2.4 billion.

The Dallas-based LTV Corp. and LTV Steel, after filing for reorganization under federal bankruptcy law in 1986, advised the PBGC that they could not and would not fund the three pension plans they sponsored.