BALTIMORE (AP) _ Federal authorities are investigating corruption and bribery at the U.S. Naval Academy, where a contractor has admitted handing out more than $20,000 in illegal gratuities.

Carroll R. Dunton pleaded guilty in U.S. District Court on Tuesday to charges that he gave bribes and illegal gratuities to a Navy public works officer and an Annapolis Housing Authority official.

Dunton, 65, is a general contractor in Annapolis, where the Naval Academy is located.

He admitted giving $20,307 worth of gratutities, including cash and household appliances, to James Weston, who was the Naval Academy's public works officer from July 1985 until his retirement in October 1989.

In return, Dunton allegedly received $3.7 million in Navy contracts.

Weston, reached by telephone at his home in Nevada, declined to comment on the allegation. He has not been charged.

Dunton also pleaded guilty to one count of giving $13,351 worth of plumbing work to Arthur Strissel Jr., who was the executive director of the Annapolis Housing Authority.

In return for the bribe to Strissel, Weston awarded Dunton's company a $559,330 contract to install gas meters at Annapolis housing projects, according to Assistant U.S. Attorney Jane F. Barret.

Dunton made a profit of $249,568 on the contract, which was financed with U.S. Department of Housing and Urban Development funds, prosecutors said.

Strissel is serving a 10-year prison term on unrelated racketeering and bribery convictions.

Academy spokesman Noel Milan confirmed that the FBI and Naval Investigative Services began an investigation in March 1989 into procurement irregularities during Weston's tenure at the academy.

''The academy is cooperating fully in the probe,'' Milan said.

Dunton, the owner of Dunton Contracting Inc., faces a maximum sentence of 12 years in prison and $500,000 in fines if found guilty.

Sentencing was set for Oct. 26.