Sen. Orrin G. Hatch (R-Utah), even while trying to shed his image as the bane of organized labor, intends to begin his new career as chairman of the Senate Labor and Human Resources Committee with a bill reducing the minimum wage for younger workers.

Such a so-called youth differential has been bitterly opposed by the labor movement and just as ardently supported by the business community and conservative lawmakers.

Until the election last Tuesday, when the Republicans captured control of the Senate and made big gains in the House, the proposal did little more then languish on the U.S. Chamber of Commerce's wish list and throw an occasional scare into the AFL-CIO.

Hatch revived its prospects in an interview yesterday, although -- in the spirit of trying to tone down his previously acrimonious relations with big labor -- he emphasized that he is willing to work with union leaders to reach an accommodation on the issue.

"It can be modified if labor will help us to know what they would like to do . . . I'm amenable to any reasonable approach to getting young people to work," said the 46-year-old conservative lawmaker who jumped to the top of labor's Capitol Hill enemies list when he led the successful fight against a union-backed revision of labor law in 1977.

In the same spirit, Hatch also relegated to the back burner a number of his earlier proposals to curb union powers and indicated he would generally rely on the incoming Reagan administration to change the way that labor laws are enforced rather than seek legislative charges himself.

Among such laws are the Occupational Safety and Health Act (OSHA) and the Davis-Bacon Act that sets wages for work on federally financed projects, both of which have been criticized by conservative business leaders as unduly prolabor in their enforcement.

But, while not moving immediately to curtail OSHA and other labor programs, Hatch said he would hold hearings on legislation to curtail them in order to hold the new administration's feet to the fire.

As for the minimum wage, however, Hatch said he may not even wait until the new Republican majority takes over the Senate in January.

If the outgoing Democratic leadership brings up the Carter administration's proposed new youth employment program during the lame-duck session that begins with Wednesday, Hatch said he will attempt to tack his youth differential proposal onto it. The youth bill is ready for Senate floor action, although Senate Majority Leader Robert C. Byrd (D-W.Va.) has not mentioned it as a "must" item for the post-election session.

Hatch's proposal would permit employers covered by the minimum wage law to hire teen-age workers at 75 percent of the hourly wage floor for adult workers. After a six-month training period or after a worker reached the age of 20, the full minimum wage would have to be paid. The minimum is now $3.10 an hour and is scheduled by law to rise to $3.35 an hour on Jan. 1.

"Everyone knows that when the minimum wage goes up to $3.35 an hour," said Hatch, "thousands, no, hundreds of thousands of kids will lose their jobs because businesses just aren't going to pay that much for young people who are only worth $2.50 an hour."

In the past, labor unions have disputed the notion that a lower minimum wage for teen-agers would create more jobs and fought the idea on grounds that it would depress wage levels generally and reduce job openings for adult workers.

Before the Democratic disaster in Tuesday's elections, there had been talk of legislation to increase the minimum wage from some lawmakers, including Rep. Edward P. Beard (D-R.I.) chairman of the House labor standards subcommittee. However, Beard was defeated, and the climate of the 97th Congress is not expected to foster this kind of liberal legislation.

"The emphasis will clearly shift . . . . The prospects for a youth differential are good in both houses," said John Tysse, labor director for the U.S. Chamber of Commerce.

Even in the old Democratic-dominated Senate, changes were so good for approval of Hatch's proposal as an amendment to the youth employment bill that the bill was not brought up before the elections, Tysse said, adding that the Republican gains in both houses will only improve the prospects.

In 1977, a youth wage floor, pegged to 85 percent of the adult minimum wage, was defeated by only one vote in the House. A similar proposal lost by five votes in the Senate.

Sen. Charles Percy (R-Ill.) also has a proposal pending for an 85 percent differential. Hatch said yesterday that if labor is willing to cooperate on a compromise, he would consider modifying the formula and imposing the differential for a trial period instead of permanently.

Along with the youth differential Hatch said he will push legislation under which business would receive a stipend for hiring hard-core unemployed workers at the minumum wage. The stipend, which would be phased out over three years, would be equivalent to what the worker would get on welfare.

Probably foremost among his immediate goals, Hatch said, would be oversight hearings on job discrimination against women. He said he would also push a number of programs aimed at creating more jobs in the private sector and a bill to provide government assistance for home health care for elderly people.

Hatch will take over the committee which has control over a number of social programs as well as labor matters, from Sen. Harrison A. Williams (D-N.J.), a long-time supporter of labor's interests in Congress. The ideological shift will be one of the most dramatic of all committee upheavals when the new Congress convenes in January.