Loral Corp., a New York-based defense electronics company, has agreed to let Ford Motor Co. withdraw about $100 million from the pension fund of Ford Aerospace employees as part of negotiations over the sale of Ford's defense division to Loral, sources said.

Ford announced earlier this month that it had agreed to sell its Ford Aerospace subsidiary to Loral for $715 million. Sources said that two competing bidders had submitted higher proposals, ranging up to $730 million. But sources said the assets from the "over-funded" pension plan pushed the total value of the Loral offer to more than $810 million.

Spokesmen for both Ford and Loral said benefits to employees and retirees would not be affected by the plan to dip into the employee pension fund. However, the proposal has alarmed Ford Aerospace employees, according to company managers and congressional sources, who have received several inquiries.

Corporate raids on over-funded pension funds have generated substantial congressional criticism in recent years and prompted legislative efforts this year to strengthen the rights of employees. Attempts by defense contractors to draw on excess pension funds have drawn intense scrutiny from the Pentagon, which has asserted that it has rights to those funds as well.

Over-funded pension plans have more money than appears to be required to meet a company's pension obligations. While this over-funding can occur for a variety of reasons, including strong investment performance, there are general concerns that the over-funding is a temporary phenomenon and that employee pensions may be at risk in the long run if funds are withdrawn.

Rep. John Dingell, the Michigan Democrat who chairs the House Energy and Commerce Committee and has been a critic of corporate raids on pension plans, said he was unfamiliar with the details of the Ford Aerospace pension plan proposal. But he said he is always "concerned about the use of this mechanism to enrich buyers or companies at the expense of their employees."

The Employee Retirement Income Security Act, known as ERISA, expressly prohibits an employer from removing assets from an ongoing pension plan. But in recent years, companies have gotten around that prohibition by terminating the pension plans.

Over the past decade, more than 2,160 employers have terminated pension plans to recover $21 billion in "excess" pension assets, according to the Pension Benefit Guarantee Corp., a federal government agency that oversees pension benefit plans. The increase in the number of mergers and acquisitions has accentuated the trend.

The Ford Aerospace pension plan is over-funded by about $300 million, sources said. Ford Motor spokesman Thomas Rhoades said the company "is not transferring all of that surplus to Loral. But we are transferring more than sufficient funds to cover all Ford Aerospace employees."

Ford declined to comment on whether the company plans to terminate the pension plan. "That is something we are still looking at," said Ford spokesman Richard W. Judy. "I can tell you it has been the subject of discussions between Loral and Ford."

Elizabeth Allen, a spokeswoman for Loral, declined to discuss whether Loral planned to establish a new and comparable pension plan for employees if Ford were to terminate the Ford Aerospace pension plan. "I don't want to answer that theoretical question," Allen said.

She added, "Ford Motor Co. is transferring sufficient pension assets to Loral to keep the pension fund for Ford Aerospace employees in a significantly over-funded position for some years to come. ... Loral is going to continue substantially the same benefits for Ford Aerospace employees that they currently enjoy, both retirees and current employees. ... They should not notice a difference."

It is unclear whether the pension plan for employees of McLean-based BDM International will be affected by the deal. Judy declined to comment on the BDM pension issue.

Congressional and government experts said employees can face harm from pension raids because an employee's retirement benefit may be based on the number of years of service at the time an over-funded pension plan is terminated, with no credit given for additional years worked.