A Peace Corps spokesman said yesterday that guerrillas in Colombia who have held a volunteer for more than seven months have offered to negotiate his release.

The spokesman said, however, that the U.S. policy of refusing to negotiate with terrorists will be applied in the case of the volunteer, Richard Starr, 31, of Edmonds, Wash.

The Colombian guerrillas, a group called the Revolutionary Armed Forces of Colombian, sent a letter Friday to a Colombian radio network offering to negotiate with the U.S. embassy for Starr's release. It also said he had confessed to being a CIA agent.

Spokesman James Cawley of the Peace Corps' parent ACTION office here said that "no Peace Corps volunteers or staff" members are connected with CIA, adding that any such connection is forbidden by law.

Starr, a botanist was abducted Feb. 14 from the town of La Macarena, where was assigned to an agency of the Colombian government to carry out botanical studies.

U.S. sources said at the time that they believed Starr's kidnaping was not planned but had just happened when a guerrilla band raided the town.

Cawley said the letter to the radio network "is the first time the group has publicly acknowledged it is holding Starr." He added that the guerrillas had passed on a letter, apparently from Starr, to be sent to his mother in Edmonds, and that the letter is on the way. Starr's mother, Charlotte Starr Jenson, visited Colombia two months ago to make broadcast and newspaper pleas for her son's release.