Nine reporters and television cameramen were convicted today of trespass charges growing out of their coverage of an antinuclear protest at a power plant construction site last June.

Similar charges against the 319 protesters arrested at the Olkahoma demonstrations, however, had previously been dismissed by the same state district court judge who found the journalists guilty. The protesters' trial had ended in a hung jury.

A reporters' rights group in Washington, D.C., immediately denounced the convictions, and said that as a result journalists could grow wary of reporting on controversy. More important, the group said, nuclear plant operators might be emboldened to control news coverage of demonstrations by threatening to cause the arrest of reporters in the course of their work.

The action by Judge David Allen Box comes during a period of increasingly frequent court tests of a First Amendment issue as yet undefined: not the constitutional right to disseminate the news, but that to gather the news.

It comes too at a time of mounting nationwide protests at nuclear plant construction sites.

Box's 60-minute session today in the old yellow brick Rogers County courthouse ended in the leveling of nine $25 fines. While his conclusions govern for now only today's case, appeal efforts have been promised by at least one of the convicted news representatives.

Any appeal eventually working its way to the U.S. Supreme Court could result in a broader, nationwide impact, just as ever greater numbers of judges, citing Supreme Court rulings, are already keeping journalists out of various courtroom proceedings.

On one key matter, Box agreed with defense lawyers, who argued that the trespass charges per se violated the reporters' First Amendment rights. He ruled that the relationship between a nuclear power company and local, state and federal government agencies is so intertwined that reporters have a constitutional right of access to a nuclear plant demonstration.

But he concluded that the Public Service Co. of Oklahoma provided suficient access to the media by setting aside a viewing area for the demonstration in question, even though the utility had, in Box's word, the "ignoble" intention of controlling news content by restricting media movements. "

The events leading to today's verdict began about 8 a.m. last June 2, when members of the "Sunbelt Alliance" arrived at the 2,206 acre, $1.75 billion Black Fox construction site 23 miles east of Tulsa. The plant is a joint venture of Public Service, Associated Electric Cooperative Inc. and Western Farmers Electric Cooperative.

Most of the reporters and cameramen on hand were in the public viewing area. The nine, however, were with the protesters, and when the crowd crossed a fence and entered the Black Fox site, they did too. Both the prosecution and the defense agreed before the media members' trespass trial that the reporters and camermen were "peaceful, law-abiding" and present only to "observe a newsworthy and significant event."

When the arrests began, reporters and cameramen in the sanctioned viewing area asked that they be allowed to go to the arrest site, and Public Service officials then shepherded then to the scene, even though a company tactics memo discussed a desire to "prevent closeup shots and battle shouts by the marchers."

The reporters escorted by utility officials were not charged, while the nine who had walked with the protesters were. The nine believed it was crucial to their coverage that they stay with the protesters. Their decision to do so, their lawyers argued, was supported by the First Amendment.

To press their constitutional claim, the nine chose to stand trial without a jury in November, and Box's ruling was delayed until today.

Essentially, Box:

Agreed with defense lawyers that Public Service and the two cooperatives -- created, regulated or subsidized by various federal programs -- are virtual extensions of government, and therefore its activities are public and subject to news coverage. He noted that Public Service even hired vans, buses and employes to help arresting officers process protesters.

Found that this press right to coverage was, however, limited, and that the limits placed by Public Service proved reasonable.He noted that the nine trespassers obtained virtually the same information as the reporters confined to their viewing area.

Decided that Public Service's property rights and the state's need to maintain law and order and protect private property outweighed claims that the press had been restricted to control the content of stories and photographs.

In an interview, Box said his ruling might have been different had Public Service not accommodated the penned-up reporters to the arrest site or if it had been proved to him that the Black Fox protest could have been covered only by trespassing. He conceded that that was an after-the-fact judgment, that the journalists took their chances and now must pay the consequences.

They are David McDaniel of the Daily Oklahoman, Vicki Jean Monks of KWTV in Oklahoma City, William A. Collard and Ronald Earl Stahl of KOCO-TV in Oklahoma City, Ben Bernstein of The Oklahoma Daily at Oklahoma University, Mark Raymond Emerson and Eli W. Nixon of The Grove (Okla.) Sun; Mike D. Kelly of The Springfield (Mo.) News and Leader and Steven Wolfson, affiliation unknown.

Assistant District Attorney Richard Sitzman expressed satisfaction that the state's interests in preserving order had been upheld. But Jack Landau, director of the Reporters Committee for Freedom of the Press, described Box's ruling as "outlandish." He said it would tell utilities "they can stage the news, and if the reporters wander off the set they're going to be arrested."