Nine out of 10 federal workers would be shifted from their attractive retirement program to the less-generous Social Security system under recommendations coming this week from a blue-ribbon task force.

For federal employes the "integration" proposals couldn't come at a worse time. Congress is clearly in the mood to whack at governmental salaries and fringe benefits. The federal retirement system is the most tempting target of all.

And despite assurances from the White House that President Carter loves you and has an open mind -- more on that later -- bureaucrats who prefer their own, independent staff retirement system to Social Security have something to worry about.

Various options to blend the Civil Service (CS) retirement system with Social Security will be presented by the Universial Social Security Coverage group. It was set up by Congress more than two years ago to study how best to accomplish merger -- or "integration," the preferred word -- of the two systems.

President Carter has sent assurances, or sorts, to the head of the government's biggest union. In a March 18 letter to Kenneth Blaylock, president of the 300,000 member American Federation of Government Employes, Carter says he:

Has not made up his mind whether to support or oppose integration of CS benefits with Social Security.

"Will entertain no proposal that would reduce the benefits of persons already retired or employes eligible to retire. Nor would I entertain any proposal that does not assure the earned benefits of those who are now covered by the CS Retirement System.

"Would insist that the CS retirement system continue to operate as a separate, independently funded system. The CS retirement fund will not be merged into Social Security, and the money in the fund must continue to be used exclusively to pay benefits to federal employes, retirees, and their survivors.

"Will reach no conclusion on the need for legislation until there has been a thorough and broad-based debate of alternatives."

Realizes that "the government, no less than any other employer . . . owes its employes and their families a security continuity in the legitimate expectations they have earned concerning their income in retirement or in the event of disability of death. This is an obligation to which I am completely committed."

The assurances are good, as far as they go. The president says he has an open mind and should "integration" come he will now allow Social Security to swallaw the huge financial reserves of the CS retirement system. But it still leaves the White House lots of room to operate, and give the president the option later on to back mandatory Social Security coverage for federal workers if he chooses.