One of every nine federal jobs -- as many as 300,000 positions -- could be shifted to the private sector over the next few years under new guidelines requiring agencies to take a hard look at "commercial tasks" now being performed in-house.

Revised rules published last week by the Office of Management and Budget require federal agencies to review all commercial-type jobs--everything from security and maintenance to clerical and publications operations--by Sept. 30, 1987, to see if any can be done better and cheaper by outsiders.

On Jan. 16 this column reported that OMB would revise the so-called A-76 contracting rules to encourage agency heads (mostly political appointees) to give industry a better chance at taking over jobs now performed by civil servants. OMB officials protested the column, insisting that the guidelines would not result in a "tilt" toward private contractors.

However, the final rules published in the Aug. 16 Federal Register have caused few tears from contractors, whom government workers often refer to as "Beltway Bandits."

The new rules give agency heads the right to estimate costs to them of doing work versus having outsiders handle it. They also give greater leeway to officials who favor shifting work to the private sector, and they set a deadline for all of them to make cost studies and/or take action.

Most of the contracting out would come in the Defense Department because it employs about half the federal civilian work force.

OMB has identified more than 11,000 so-called commercial tasks government-wide that it says should be considered for potential contracting out. OMB says the number of jobs to be studied for possible contracting out is 186,000. But congressional sources say that as many as 300,000 jobs fall into the definition of "commercial-type" functions that may be ripe for contracting out.

Nondefense agencies may, under the new guidelines, contract out work if it involves 10 or fewer employes without making cost-comparsion surveys that are required by Congress for the Army, Navy and Air Force.

Political appointees in Commerce, Interior and the Department of Health and Human Services who want to get the government out of what one called "the business of business" have been eagerly awaiting the contracting out guideline changes.

Federal employe unions, which stand to lose members under contracting out, believe the revised contracting rules represent a clear tilt toward industry. "They can chip away at agencies, contracting out 10 jobs here, 10 jobs there, without any oversight," a union official said.

A career government personnel director said "contracting out always appeals to the political appointees because they can say they cut the size of the federal bureaucracy . . . when all they are doing is shifting the work and costs. The taxpayers still have to pay for it in the end and when contractors do it--and all you have to do is read the papers about cost overruns--sometimes it winds up costing Uncle a whole lot more."

Government employe unions will go to Congress to seek specific bans--as part of appropriations bills--to block or delay contracting out. Legislators in districts with major federal and military installations frequently have been successful in blocking contracting out attempts in Defense and VA. But the new guidelines giving agency heads the right to contract out small operations on their own represent a much greater threat to the job security of government workers than any of the legislative proposals advanced by the Reagan administration.