In June, the federal government will begin a controversial five-year hiring experiment aimed at building a "more representative" work force by setting aside up to 20 per cent of the jobs in agencies for women and minority group members.

The so-called Sugarman Plan (named for Civil Service Vice Chairman Jule Sugarman) will require agencies to have "goals" and "timetables" for increasing the number of "under-represented" minorities in various occupations.

Persons hired under the "special emphasis" program would not necessarily have to come through regular competitive merit channels. But they could be converted to career federal job status in 24 months if they perform satisfactorily.

Sugarman is the point man of the Carter administration pushing for innovative work programs. His main thrust in the number two job at the CSC - the government's personnel and merit system agency - has been to increase the number of women and minorities in job fields now dominated by white men.

CSC Chairman Alan K. Campbell has emphasized that the special emphasis hiring plan will be accomplished with goals set by agencies and is not a "quota" system. Sugarman believes that in some cases - in such occupations as teaching and library sciences - white males will be found to be "under-represented" and therefore eligible for the special hiring help.

Under the program - which has drawn fire from a number of sources - agencies will determine the race, sex and ethnic makeup of employes in various occupations. If any group is found to be "under-represented," then agencies may hire people from the under-represented group outside normal competitive civil service channels. Up to 20 per cent of the job opening sin those fields may be earmarked for "special emphasis" hiring.

Determination of under-representation would be based on the number of women and minorities in those federal job occupations compared with either their numbers in the general work force nationally or their numbers enrolled in college programs in those various career disciplines.

A recent CSC memo to all agencies says that "current competitive examining procedures have not resulted in a representative work force" in many federal occupations. As a result, CSC said, agencies must push ahead with the special emphasis hiring to see "if broader representation can be achieved and if the selection methods used produce individuals who perform as well as those hired through traditonal competitive processes."

The legal staff of CSC, anticipating charges that the Sugarman plan might be unconstitutional, have checked it thoroughly and reportedly are confident it can weather any court test.

Although the special emphasis hiring program would be open to all candidates, women and minorities would be the chief beneficiaries since relatively few of them are in high-level, good-paying jobs in government.