An attractive but long-shot 10 percent pension sweetener bill designed to lure senior Defense civilian employees into retirement may, in fact, be keeping them on the job longer as they wait for it to become law.

Talks with employees and manpower experts at the Pentagon and Office of Personnel Management indicate that some workers may be delaying their retirement to see what happens to the pension-bonus bill sponsored by Rep. Barbara Boxer (D-Calif.).

Her bill would give Defense civilian employees a five-year age-service credit if they retired immediately. For people already eligible to retire, that add-on would increase their lifetime pension 10 percent. It is a mouth-watering concept for employees, but its cost means it is unlikely to become law. It also is unpopular with the 57 percent of the federal work force outside the Defense Department that would not benefit from the bonus.

Since January, the government has offered early retirement (immediate pension for anyone with 25 years' service or anyone age 50 with 20 years' service) to 2,800 civilians. Most are in Defense units that are cutting back. So far, only about 100 have taken early retirement. Officials speculate many are waiting to see what happens to the Boxer bill.

Typically when U.S workers are offered early retirement:

Only one in six takes it.

White-collar workers grab the offer quickest. For example, in a June 1 through Aug. 30 early-out period, most white-collar workers would retire within the first three days of June or July.

Blue-collar workers are more cautious. In the same June 1 through Aug. 30 early-out period, most of them would wait until late July or late August to retire.

The average early retiree is 52 years old. The normal retirement age for federal workers is 61.

The weather gets considered. Workers are more likely to take early retirement if it is offered in spring or summer than if the option is presented in late fall or during the winter. Tax-Deferred Investments

President Bush is expected to sign a just-passed bill allowing U.S. workers total freedom to invest in any or all options of their thrift savings plan. Currently, people in the new Federal Employees Retirement System can put only a part of their investment (and none of the government's matching contribution) in the savings plan's stock and bond options.

Workers in the old Civil Service Retirement System are limited to investing in the Treasury securities option.

If the change becomes law, workers could put all their contributions and any government match into any or all of the investment options. For the 12 months ending in May, the stock market option (C-Fund) had a 16.26 percent rate of return. The bond option (F-Fund) earned 8.49 percent, and the Treasury option (C-Fund) earned 8.59 percent.

If the president approves the investment change, workers will be able to revise their investment options starting with the next open season, which begins Nov. 15.