Raymond J. Donovan, Ronald Reagan's choice for secretary of labor, is a New Jersey highway construction firm executive and a top Republican fund-raiser who is a virtual unknown on the national labor scene.

But his selection, one of several conservative appointments announced or under consideration by the president-elect, was immediately applauded by the conservative National Right to Work Committee and many business groups. Friends and business associates expect Donovan to do Reagan's bidding in pushing for items like a sub-minimum wage and scrapping regulations regarded by business as unnecessary and counterproductive.

As labor secretary, he would be in a good position to do that: the Labor Department is one of the nation's largest regulatory agencies, with responsibility for plant and mine safety rules, pension benefit regulations, union-management relationships, affirmative action programs and others.

To further the antiregulation cause, the U.S. Chamber of Commerce yesterday urged Reagan to choose a health expert from industry as assistant secretary of labor in charge of the Occupational Safety and Health Administration. The chamber's first choice is Dr. Bruce Karrh, corporate medical director of E.I. duPont de Nemours & Co., but it also would be happy with Dr. Paul Kotin of Johns-Manville Corp. or Dr. Harold L. Kusnetz of Shell Oil Co.

Donovan's nomination for the top labor post yesterday prompted a "who is he?" chorus from national labor leaders.

Typical of that reaction was that of AFL-CIO President Lane Kirkland, who said, "I look forward to meeting Mr. Donovan."

Frank F. Fitzsimmons, president of the 2.3-million-member Teamsters union, the nation's largest union and the first to back Reagan's candidacy, was one of the few national labor leaders to voice familiarity with Donovan, 50, an executive vice president of the Schiavone Construction Co. of Secaucus, N.J.

"While we supported another candidate" for labor secretary, "we are well aware of Mr. Donovan's distinguished record and his background in labor," Fitzsimmons said in a prepared statement.

Teamster sources said yesterday that their president's "familiarity" was obtained Friday night in a telephone conversation with Reagan.

"Fitz talked to the president-elect Friday night, primarily about the secretary of labor position," one Teamster source said. "Reagan told Fitz what he had in mind." Sources said that Reagan transition team members had also briefed Fitzsimmons, who had previously backed Betty Southard Murphy, a former chairman of the National Labor Relations Board, for the post.

Donovan is well known among unions and builders in the Northeast, where his firm, the 277th largest construction operation in the nation, carries a lot of clout in highway building and other public works jobs.

Donovan, a former Roman Catholic seminarian who enjoys a reputation as a self-made man, joined Schiavone as a shareholder and vice president when the company had assets of less than $50,000, according to New Jersey construction industry sources. Last year, by comparison, the company did $55.9 million worth of business, mostly in New Jersey and New York.

Much of that growth is attributed to what industry sources yesterday called Donovan's management ability as well as his ability to win labor peace, an important commodity in the construction business. Donovan's primary responsibility at the company was dealing with unions such as Local 825 of the International Union of Operating Engineers.

"The people in that local and in all of our locals in New Jersey and New York called me and told me that they think he is a man of his word, a good, square-shooting businessman," Operating Engineers President J.C. Turner said from his Washington office.

Turner said he "heard that Mr. Donovan was a conservative . . . but I don't know what, if anything, that really means."

According to groups like the National Right to Work Committee, which has been seeking a constitutional amendment outlawing union membership as a condition of employment, it means that Donovan supports their position.

"One of his close friends contacted us a month ago to let us know that he was a good bet for the secretary's job," said Carter Clews, a right-to-work committee spokesman. "We submitted specific questions to him through his friend -- questions about where he stood on issues important to us. He came down in our favor on every one."

"We at the Natioal Right to Work Committee welcome the appointment of Raymond J. Donovan. We . . . look forward to seeing the Department of Labor taken out of the hands of union professionals and placed in the hands of American workers," said Reed Larson, the committee's president.

Donovan also is regarded as a major backer of the Washington Legal Foundation, which has been calling for investigations of organized labor's political use of union dues and fees. One conservative source said yesterday that Donovan has contributed $100,000 to the group.

"I do know that he is a supporter of our group and its issues, although I don't know how much he might have contributed," said Paul Kamenar, the foundation's director of litigation.

The 2-year-old foundation is chaired by John T. (Terry) Dolan, who is also head of the National Conservative Political Action Committee (NCPAC), which poured millions of dollars into this year's campaigns of conservative candidates -- nearly all of whom were opposed by organized labor. WLF, a "public interest law firm," is dedicated to "defending the First Amendment rights of corporations . . . and the rights of corporations to be free from overregulation," Kamenar said.

New Jersey Republicans credit Donovan, a onetime Democrat, with raising $175,000 in the state to help Reagan's general election effort. Other sources say he raised $600,000 in the presidential primary for Reagan, outperforming individual Reagan fund-raisers across the nation.

"He's more conservative than I am," said Raymond Bateman, a ranking New Jersey Republican who in 1977 unsuccessfully sought the state's gubernatorial seat. Donovan was Bateman's fund-raiser in that race.

Bateman said Donovan "is very close to Ronald Reagan personally, much closer than anybody else from around" New Jersey.

"I think he'll be a total reflection of Reagan" in the labor secretary's job, Bateman said of Donovan.