Worried about your federal retirement program? Want to buy into a supplemental package that provides higher retirement income, and protects you from any cutbacks in the federal program because of congressional action, or social security merger?

Relief is on the way. Maybe.

In a surprise move Friday, delegates to the American Postal Workers Union Convention voted in favor of creation of a supplemental pension plan paralleling the U.S. retirement system. It would be sponsored and controlled by this AFL-CIO union, but open to virtually any federal or postal employe willing to join it.

Backers of the union-backed pension plan said that any federal employe now eligible to participate in the government's retirement program could join the APWU plan -- which has yet to be created -- by becoming "associate" members of this 270,000 member union.

Thousands of non-members are now paying token dues -- raised by this convention from $30 to $35 per year -- to participate in the union's health benefits program.

Officials of the union were stunned by the pension plan vote, which was rammed through in the hectic last day of business. Creating and maintaining pension plans is a costly, complicated business. Yet it was passed after a relatively short, though heated, debate.

Details of the program are non-existent. But the union is now mandated by its membership to set up a voluntary supplemental retirement system that not only provides extra retirement benefits but also would take up the slack for any financial benefits that are lost due to congressional or White House reductions in the U.S. pension system.

Congress is considering plans to eliminate one of the two cost-of-living (COL) raises that now go to federal and postal retirees each year. Under the compromise in the works on Capitol Hill, the COL reduction would be a one-time affair. The White House, however, wants to end the twice yearly pension adjustments, now due in March and September in favor of a single annual retiree raise.

Insiders expect Congress will make major cutbacks next year in the federal-postal pension program. One of them would limit retirees to a portion of the actual cost of living increase, perhaps 75 percent, rather than a full inflation catch-up. Retirees are due a 7.7 percent raise in September. That could be deferred, however, until March 1980 if Senate-House budget conferees accept a bill already approved by the Senate. The House has proposed giving retirees the September raise, but eliminating next March's increase. The final payoff date will be decided when Congress returns from its current recess.

The APWU retirement plan -- which could make this the biggest and the brokest federal union -- came up so quickly and was passed with such limited debate that nobody knows exactly how it would work. More importantly, nobody has any idea how it is to be financed.

Delegates who opposed the union pension system warned that similar plans run by private sector unions have gone broke because the number of people paying into the funds is not enough to provide benefits for retired members. They argue that the U.S. Postal Service, which is facing big changes because of automation and electronic mail transfer, could become the government's version of the Chrysler Corp.

Several delegates said that perhaps the union could negotiate with the U.S. Postal Service to pay for the union-sponsored retirement program.

The realistic response to that is "lots of luck." Retirement systems are extremely costly and bargainers for the U.S. Postal Service are most unlikely to include the concept in any new contract agreement.

Despite requiring new services from the union, and creating more national and local officers to service members, delegates twice defeated a proposal to raise dues. Although the services they have requested will cost between $700,000 and $1 million per year more, delegates here rejected proposals to raise their national dues -- now less than $5 per month -- by $1 per member per month.