Robert A. Rowland, the embattled head of the Occupational Safety and Health Administration, resigned yesterday, saying he is "proud of my record" but "weary" of persistent criticism about his financial holdings and his approach to such job-safety issues as field sanitation for farm workers.

Rowland's resignation, effective July 1, came on the same day that the Office of Government Ethics concluded that he had not violated federal conflict-of-interest laws by participating in OSHA decisions that potentially affected chemical, pharmaceutical, petroleum and other corporations in which he owns more than $1 million in stock.

Rowland, who received a presidential recess appointment last June and had never been confirmed by the Senate, is the latest of a half-dozen administration officials to leave office amid controversy recently. No replacement was named for him.

The AFL-CIO, in a terse statement, said yesterday: "For the health and safety of all American workers, we hope Rowland will be succeeded by an effective health professional."

A millionaire Texas lawyer and prominent Republican fund-raiser, Rowland, 53, said in an interview that he is leaving because of a combination of "homesickness," distaste for the criticism and the desire to start up a new business "and get in a little hunting and fishing" on his south Texas ranch.

He said that the timing of his announcement and the ethics office report were coincidental and that he had not been asked to leave by Labor Secretary William E. Brock, who said recently that he is carefully reviewing OSHA matters because the agency is a leading source of complaints from organized labor.

Brock said in a brief statement that "this administration owes him a debt of gratitude for his unflagging commitment and tireless efforts on behalf of the President. Bob faced difficult and controversial issues while maintaining his commitment with integrity and diligence."

From the time President Reagan named him to head OSHA last June, Rowland faced sharp attacks from organized labor and Democrats because he lacked a health-and-safety background and because they thought that he showed pro-employer bias. The AFL-CIO said Rowland had voted against upholding OSHA citations in 84 percent of the cases he reviewed while serving from 1981 to 1984 on the Occupational Safety and Health Review Commission, which hears OSHA appeals.

OSHA has enacted only one new standard regulating toxic substances in workplaces in the last four years. The issue was highlighted recently with Rowland's controversial decisions not to enact tighter rules for formaldehyde and other chemicals and not to enact a standard requiring clean drinking water and toilets for farm workers.

The Reagan administration's posture at OSHA under Rowland and his predecessor, Thorne G. Auchter, was largely aimed at creating a "nonadversarial" approach to health and safety laws. OSHA had been an overzealous policing agency, the Reagan appointees said, but would now shift to advising employers on how to improve conditions rather than emphasizing citations and fines. OSHA cut 25 percent of its staff during the administration and reduced all categories of citations between 1981 and 1984.

"I am proud of my record at OSHA," Rowland said, "I think the agency is in fine shape, morale was high, contrary to the critics allegations."

"I take a great deal of pride in having played a role in giving the American working man and woman the safest possible workplaces. On-the-job injuries and deaths are at their lowest levels since this agency was formed," Rowland's resignation statement said.

A recent report by the nonpartisan, congressional Office of Technology Assessment attributed that drop to the economic recession rather than OSHA, whose policies the report said, "may have reduced an already-weak regulatory effort." Congressional sources said Rowland's nomination had not been forwarded to the Senate largely because Republicans were not eager for the expected battle with Democrats, who were optimistic that they would block it.

Rowland said that he originally planned to serve only about six months to help OSHA's transition into the second Reagan term, but that he found the job more difficult and frustrating than he had imagined, particularly after his boss, former labor secretary Raymond J. Donovan, was indicted last year on criminal fraud charges.

Yesterday's report by the ethics office concluded a "review" requested by House Education and Labor Committee Chairman Augustus F. Hawkins (D-Calif.). Rowland had participated in decisions not to enact tighter rules for formaldehyde, benzene, and ethylene oxide while he had financial interests in firms including Tenneco, Exxon, Eastman Kodak, and Monsanto, which use such products.

Office of Government Ethics Director David H. Martin told Hawkins in a letter yesterday that Rowland acted within the law under the terms of a conflict-of-interest "waiver" granted by Donovan last September. The waiver permitted Rowland to participate in broad policy-making OSHA decisions such as rule making, as long as he disqualified himself from matters such as compliance actions, investigations, or citations against those specific companies.

Rowland is at least the fifth administration official to resign under fire in the past three months. Donovan resigned after failing to overturn his indictment. Office of Personnel Management Director Donald J. Devine took a temporary OPM position after his term expired; he then resigned but now awaits a possible second term as OPM head.

Eileen Marie Gardner, an Education Department aide, resigned under fire for her writings about the handicapped. Another new Education Department appointee, Lawrence A. Uzzell, resigned after protests about his remarks that all federal programs for elementary and secondary education should be abolished. Marianne Mele Hall, the Copyright Royalty Tribunal chairman, resigned after publicity over her role in a book considered derogatory to blacks.