Several Fairfax County supervisors said yesterday that County Board Chairman John F. Herrity should have disclosed he was a real estate partner of a county businessman before he voted on a town house project proposed by his partner.

Most of those supervisors said, however, that they believed Herrity's failure to reveal his business relationship with the developer, Hersand Builders Inc. of Fairfax, was an oversight and that it was unlikely he would be prosecuted.

"I'm sure if he had to do it over again, he would have disclosed it," said Supervisor Thomas M. Davis III (R-Mason). "This just slipped through. I don't think it was deliberate. He just missed it. I'm sure it was an oversight."

"If I had known there was a potential conflict, I would have disclosed and then disqualified myself," said Supervisor Joseph Alexander (D-Lee). "I just think it slipped his mind. I think it was an honest mistake."

Herrity, chairman of the county board for 10 years, disclosed Thursday night that he had asked Fairfax Commonwealth's Attorney Robert F. Horan Jr. to examine whether his actions on a rezoning request by Hersand Builders was proper. He issued a two-page letter he had written to the prosecutor and declined to answer any questions about the issue, the first conflict-of-interest controversy that has personally involved Herrity.

The Associated Press quoted Herrity yesterday as describing his association with Hersand Builders' President Herbert L. Aman III as "a customer relationship." Virginia and Fairfax conflict laws say "customer relationships" with a retail store, public utility or bank are exempt from the disclosure requirements.

Herrity owns a one-quarter share in an office condominium unit in Fairfax City in partnership with Aman and Aman's wife Sandra, according to county records and Herrity's letter. The Amans own a 50 percent interest in the unit. Herrity did not reveal who controls the remaining one-quarter interest.

Neither Herrity nor the Amans revealed their interests in the office in a rezoning application Hersand filed for 137 town houses in the Springfield area.

Herrity was one of two supervisors to vote against that application, which was approved on a 6-to-2 vote. Moments after the request was approved, Herrity joined the other seven board members at the meeting in granting Hersand's request for exemptions to county development standards.

Herrity paid $10,157 for his share in the condominium unit last Dec. 18, less than two months before the vote on the town house rezoning.

The Associated Press said Herrity strongly denied during an interview Tuesday that he had a conflict. "It's a personal business matter . . . ," he was quoted as saying. "It has nothing to do with Fairfax County. Zero, zilch. Even if he were a partner, I don't think it would make any difference."

Horan said yesterday that it was "very unusual" for someone to request his advice on a possible criminal violation after the fact. "If it's a conflict, I'll prosecute," he said. "If the letter indicates that a crime was committed, it makes no difference how I find out about it. I would prosecute."

County law requires board members, before participating in a land-use issue, to disclose whether they "either directly or through a partnership . . . has or has had any business or financial relationships" worth more than $50 with an applicant in the preceding five years.

In his letter to Horan, Herrity said he participated in the vote because Hersand's application did not indicate "that there would be any problem in my participating" in either the debate or the vote on the rezoning request.