In a surprising move, Maryland Public Service Commissioner Ronald A. Guns recused himself yesterday from a crucial regulatory case to determine if Verizon Communications Inc. may offer long-distance phone service in the state.

The recusal was an abrupt turnaround from last week in which competitor AT&T; Corp. had filed a motion to delay the Verizon long-distance case and to have Guns barred from the hearing because of his former employment at Verizon. The Baltimore Circuit Court denied the request for a stay.

But yesterday - on the fifth of six days of hearings - Guns announced that he would no longer take part in the proceedings because one of his five grown children has been employed by Verizon since February 1999.

"I have always attempted to be totally aboveboard in my dealings with the commission, the stakeholders and the general public," Guns said shortly after PSC Chairman Catherine I. Riley called the hearing to order.

"Nowhere in the state process of taking this position or in subsequent documents required to be read and signed by me instructed me to make public the employment of any of my five grown children. ... However, as a result of recent events, it concerns me that some parties may not have known or may not know that my son works for Verizon.

"Because I have always tried to be open about my prior relationship with Verizon, I feel the fact that many parties may not have known about this relationship compels me to recuse myself from this proceeding," Guns said.

Jeff Roberts, an AT&T; spokesman, declined to discuss Guns' recusal, saying only, "We did file a motion for different reasons, but this particular announcement is something separate from that. It's best to let it speak for itself."

The Circuit Court is still expected to rule on whether Guns was correct to participate in the case.

Guns' former work status has been an issue of consternation for competing companies since May, when Verizon filed its application to offer long-distance service. Verizon is seeking state approval, before asking the federal government, to add long-distance service in Maryland as it has done in several other states.

But Guns, who is a former Democratic state legislator from Cecil County, maintained that despite a 29-year career with Verizon he could remain impartial in telecommunications cases.

He had also taken his pension from Verizon in a lump sum after he retired to end all financial ties to the phone giant.

While state law does not prohibit Guns from participating because of a son or daughter's employment, said PSC General Counsel Susan Stevens Miller, Guns felt that parties in the long-distance case - who were unaware of that information - may have lost out on an opportunity to object.

"This was a very difficult decision for him," said Miller, whose advice Guns sought before recusing himself.

"But while he thought it was common knowledge that everyone knew about his son, he had not been required to put it on the record anywhere.

"It is the commission's view that this would not preclude him from sitting on other Verizon cases, but he felt it would be better if he stepped away from this one," Miller said.

The Verizon long-distance case will continue Monday. After that, the commission could issue a report on its findings to the Federal Communications Commission.