THE REAGAN administration has apparently selected the Federal Trade Commission as the first institution target of its campaign against government regulations. Last week, the Office of Management and Budget proposed that the commission be stripped of the staff and funds to do part of its assigned job: help enforce antitrust laws. This week, OMB Director David A. Stockman went further. He suggested in an interview that the FTC should be abolished.

The idea of dismembering or killing this particular independent regulatory agency was bound top appeal to those who believe, as does Mr. Stockman, that the federal government should rarely interfere with the activities of the marketplace. The commission has been a pain in the neck for many businesses during the last decade. It is still recovering from the beating it took on Capitol Hill last summer. It appears to have many more enemies than friends, and its public image is that of a meddling monster whose goal is to strangle American business. It is, or so it would appear, an obvious target in the war on excessive regulation.

But it's not quite that simple. The major constituency of the FTC is small business, not the consumer movement, as the current argument has it. Its major job, properly conceived, is to protect the marketplace from predatory and deceptive business practices. One can quarrel with some of the initiatives the commission has taken -- and still regard it as a worthwhile protector of business and consumers. The world might not know the difference if the FTC were eliminated, as Mr. Stockman asserted, but the marketplace would know that difference quickly in terms of advertising, pricing and collusion.

While there is a respectable case to be made for getting the FTC of the antitrust business, OMB has gone about making it backwards. In the first place, it is unwise to have legislation on the books that is unenforceable. Yet, that is what OBM has in mind. It has not requested legislation to transfer the FTC's responsibilities to the Department of Justice. It has just proposed denying the commission the money to do the job Congress has told it to do.

Beyond that, eliminating the FTC in the antitrust field would -- in theory anyway -- increase the workload of the Department of Justice. But OMB is not suggesting any additional staff to take on that work. You do not have to approve every aspect of the existing antitrust laws to think this is not a good idea. Congress should take a very hard look