The Federal Trade Commission yesterday proposed granting labor unions the automatic right to intervene in the agency's cases when divestiture of a company's assets is a possible result.

The unique proposal would lift from FTC rules a labor union's need to petition the commission for the right to intervene in a case. Now, the interests of a party like a labor union must be demonstrated before a group is granted intervenor status.

Although the proposal was only put before the public for comment, it drew immediate comment from a commission member, Patricia Bailey.

"What is proposed here is an institutional change of some proportions which to my mind should be implemented only after thoughtful inquiry into a number of issues," Bailey said.

Bailey suggested that the FTC should have the views of the Justice Department's antitrust division before the proposal goes into effect. Further, Bailey wondered about the effect of the proposal on ongoing cases and asked about the rights of other intervenors.

Under the proposal, labor organizations would have up to 60 days after an antitrust complaint is filed to tell the FTC of its intention to intervene.

After the 60 days pass, labor unions would have to request the granting of intervenor status from the commission or a law judge assigned to the case.

The issue has been raised by several labor groups in recent years and was prompted by a petition by the American Federation of Grain Millers, which asked to be named intervenors in the FTC's so-called cereal case, which involves the nation's leading cereal manufacturers and alleged monopoly practices.