The Reagan administration, which is planning to eliminate 75,000 federal jobs by 1984, wants to cut another 75,000 in the following three years, partly as a result of its New Federalism program, federal officials revealed yesterday.

The new plan is certain to raise fears of federal employes already anxious about the current round of "reductions in force" and to increase the concern of business executives worried about the effects of a shrinking federal work force on the Washington area economy.

Whether a cut of 75,000 in 1985-87 materializes, however, will depend on the fate in Congress of Reagan's proposal to transfer more than 40 federal programs to the states, as well as on the attitude of whatever administration is in office then.

An official of the Office of Management and Budget said the 75,000 figure is a "goal" for a reduction in federal positions in those years through the New Federalism program and through other steps such as "further computerization, further efficiencies and additional contracting out."

He said it will be "quite a while" before the staff reductions attributable to the programs transfer is apparent. And if Congress rejects the transfer, "obviously a big portion of it the jobs cutback is going to be lost," he added.

Figures released by some departments, however, suggest that programs being transferred to the states don't involve as many workers as their budgets might suggest.

The two biggest programs the administration wants to turn over to the states are food stamps and Aid to Families With Dependent Children, which have a combined cost of $16.5 billion.

According to the Agriculture Department, 154 employes in Washington are involved in the food-stamp program, and 844 work on all its feeding programs. Nationwide, 2,696 Agriculture employes handle its food programs.

The Department of Health and Human Services said 235 employes here and 480 nationwide work on AFDC.

In many cases, employes who work on programs slated for transfer have other duties as well, and their positions wouldn't necessarily be eliminated, spokesmen for several agencies said.

Reagan announced last fall his intention to reduce federal employe levels by 75,000 over the next three years. He said much of the reduction would be accomplished by not replacing some of the 200,000 employes who leave the government each year.

Further details of how those cuts will affect the federal work force in the coming year will be included in the fiscal 1983 budget, which will be released next week.

Local business executives and economists, who say the private sector is growing here while the federal work force is being shrunk, have expressed confidence that the area's economy can absorb the impact of the cuts Reagan has proposed through 1984. But some retailers say they are being hurt by the caution shown by federal employes worried about their job security.