The House and Senate have tentatively agreed to eliminate a windfall quirk in federal retirement rules.

It allows some people to work part time for most of their careers but still retire on the same pension as full timers who paid much more into the retirement fund.

Some part timers convert to full-time status before retiring to take advantage of government rules that base pension benefits on years (but not hours) worked, and the employe's average salary over the best-paid three-year period.

Uncle Sam has about 208,000 part timers, including about 12,500 who work here.

The General Accounting Office several months ago produced a study illustrating what it described as inequities in the retirement law.

In one example, GAO outlined the careers of two employes with 30 years of service. The part timer, however, worked only 34,320 hours, while the employe who worked full time for an entire career put in 62,400 hours.

But because benefits are based on years of service and a portion of the highest three-year average salary, both retirees qualified for annual starting pension of $28,753.

The Senate budget reconciliation bill includes a provision that would prorate retirement benefits based on hours worked. It would not affect hours that part timers already have credited toward retirement, but would prorate them in the future if the change becomes law.

The House has approved similar language in its budget reconciliation bill, which covers a wide range of proposals to cut spending. But because other features of the House bill are different in the Senate measure, the bill has gone back to the Senate for action.

There is no deadline for approval of the reconciliation bill, even though it deals with the fiscal year that ends Sept. 30. Nor is there any assurance that the Senate and House will reach agreement on the legislation that they have been working on for months.

But congressional and government insiders say there is no significant opposition to closing the retirement loophole for part timers. They say that if a reconciliation bill is approved, the change will be part of it.