Signaling a new get-tough approach to federal contractors whose hiring and promotion policies still discriminate against certain groups, the Labor Department yesterday announced it would be taking sole responsibility for enforcement of equal employment opportunity rules.

The move involves a major consolidation of equal rights compliance programs, previously handled by 11 different Executive Branch agencies, into one super agency under the Secretary of Labor.

Heralded by Labor Department officials as a victory for proponents of and efficiency in government, the consolidation also is likely to confound those companies that in the past have found it advantageous to play agencies against one another and slip between the cracks.

"This is going to help eliminate inconsistencies," said Wldon Rougeau, director of the newly consolidated program. "It will help eliminate duplication of effort and it will improve enforcement, to the benefit of people who have been discriminated against in the past."

More than 250,000 contractors employing about 31 million workers are currently covers by federal contract compliant requirements. These requirements forbid companies that do business with the government from discriminating in their hiring because of race, color, sex, religion, national origin, handicap or veteran status. They also force employers to adopt affirmative action plans for hiring and promoting those who have been the victims of past job bias.

President Carter made the consolidation effective by an executive order he signed Wednesday. In highlighting its significance, Labor Secretary Ray Marshall yesterday said in a prepared statement, "For the first time, there's only one name to remember for federal contract compliance: OFCCP."

That stands for the Office of Federal Contract Compliance Programs, which is itself still a mouthful. Moreover, to handle its new responsibilities, OFCCP has ballooned in size from a relatively cozy administrative unit of 200 employees to a more bureaucratic 1,500 with plans to open 71 offices in 63 cities.

But the promise of the consolidation, government officials said, is not merely to merge personnel and resources under a single roof - it is also to unify policies and procedures.