Dr. Arthur Hull Hayes Jr., who moved to reduce federal regulation of the drug industry as commissioner of the Food and Drug Administration, is resigning to become dean of New York Medical College in Valhalla, N.Y., this September, according to informed sources.

Hayes' planned departure comes after the inspector general of the Health and Human Services Department questioned his acceptance of $4,300 in honoraria for speeches to private groups, some of which were made during official trips financed by the FDA.

Hayes said through a spokesman that he was not leaving because of the inquiry and was in the process of resolving the matter by repaying some disputed expenses to the FDA.

Inspector General Richard P. Kusserow had examined reports that Hayes received overlapping travel payments from the FDA and a private research center for a trip to Seattle last year. In addition, Kusserow found that Hayes had accepted free lodging from industry trade groups and free travel on aircraft owned by Hershey Foods Inc. and General Foods Corp.

"I think I'm a goddamn good commissioner, I think I am an honest person, I know I'm a clergyman and I'm also a good physician," Hayes, 50, said last March. "I don't think there is a soul in this world that knows me that thinks I am dishonest or trying to make a buck."

The Justice Department declined to pursue the matter, but the U.S. attorney in Baltimore, J. Frederick Motz, said in a letter last April, "Dr. Hayes has shown an insensitivity to the principle that government employes must scrupulously avoid the appearance of impropriety in their dealings with the public."

Hayes, a respected cardiologist, has said he hoped to cut the review time for approving new drugs by 25 percent over the next three years. This has prompted consumer groups to complain that the FDA is relying too heavily on drug companies to detect possible hazards in their own products.

The criticism reached a peak when the FDA approved use of the anti-arthritis drug Oraflex, only to learn of reports that the drug caused deaths and adverse reactions in Britain. The FDA was still studying these reports last summer when the maker took the drug off the market.

A House subcommittee also criticized Hayes last year for allowing a potentially hazardous infant formula to be marketed, and Hayes conceded that the administration's "cost-benefit analysis" had delayed a regulation that might have prevented this.

Consumer groups have urged the FDA to warn the public of adverse health effects by requiring better labeling for prescription drugs, aspirin and salt content in foods, but Hayes has stressed voluntary education by industry. Some industry officials have complained that Hayes did not go far enough in carrying out promises of regulatory reform.

Hayes has said that streamlined regulations were responsible for quick approval of important drugs such as timolol, which is designed to protect patients against second heart attacks. He also moved quickly last fall to require tamper-resistant packaging for nonprescription drugs after seven persons died from taking Tylenol capsules containing poison.