Federal officials anticipate a big increase in the number of job-related arbitration cases in government if Congress enacts a broad new labor-management plan the president has proposed as part of his "reform" of the civil service.

The change would be a recording shot-in-the-arm for federal unions whose membership has reached an almost no-growth level in recent years. Since government unions cannot strike or bargain for wages or fringe benefits, their primary appeal to the average worker is the promise of providing some measure of job protection.

Currently, the number of cases unions and federal agencies take to binding arbitration for the 1.1 million union-covered employes runs about 700 a year.

Although the number of arbitration cases in government has increased dramatically in the past few months, it is still well below the major industry rate. General Motors, for instance, with 550,000 employees, had 1,500 cases sertified for arbitration last year although most of them were settled before actually being heard.

Under the new White House labor-management language, the types of "adverse actions" that could be taken to arbitration would be expanded to include discrimination complaints, demotion and fringes. Arbitration is now generally limited to disputes about sick leave, overtime and for short-term suspensions.

In most cases, unions and agencies split the price of an arbitration, which now averages $840 a case, excluding attorney's fees.

The new labor-management law proposed by the White House (primarily to keep AFL-CIO support for the rest of the reform package), would let employes covered by negotiated agreements choose between two separate adverse action appeal routes.

They could continue to use the present system, through a Merit System Protection Board that would replace the Civil Service Commission. That is free of charge. Or they could take their case to blinding arbitration if that becomes a part of the negotiated agreement.

It is expected that union and management would continue to split arbitration costs.

But one agency, the Community Services Administration, now has a "loser-pay-all" agreement with its american federation of Government Employees local.

If Congress enacts the reform plan, with the labor language intact, union membership could be expected to climb. It would give the organizations more clout in their agencies, and should make them more appealing to nonmembers.

The drawback, from the viewpoint of unions and dues-paying members, is that nonmembers covered by agreements would have to be served, too. The White House remected union appeals for and agency shop that would have required nonmembers to pay for the services they get from unions.