A federal judge yesterday threw out most of the key charges in the Federal Election Commission's long-running case against the Christian Coalition, rejecting the argument that the conservative group had illegally campaigned for Republican candidates and illegally coordinated its activities with them.

The decision comes at a time when outside groups across the political spectrum -- following the Christian Coalition's model -- are spending millions of dollars on election-related mailings and advertisements, and legal experts said the ruling by U.S. District Judge Joyce Hens Green only clears the way for more such spending outside of the reach of federal election law.

The FEC had claimed that the Christian Coalition's massive distribution of voter guides constituted illegal corporate contributions totaling $1.4 million to various GOP candidates -- including President George Bush's 1992 reelection campaign -- because coalition officials worked so closely with campaign aides.

In her 108-page decision, Green dismissed the bulk of the case. But she ruled that in two specific instances -- mailing a 1994 flier supporting then-Rep. Newt Gingrich (R-Ga.) and turning over a political list to 1994 Virginia Senate candidate Oliver L. North -- the group crossed the line into illegal partisan activities.

In the Gingrich case, Green said, the Christian Coalition went too far because its language so clearly supported -- or in the words of election law, "expressly advocated" -- Gingrich's election. In the North campaign, she said, the Christian Coalition overstepped by providing the campaign with a valuable list of state supporters, an impermissible corporate contribution by the group, which is incorporated in Virginia.

The ruling has implications for the 2000 campaign well beyond the Christian Coalition -- as demonstrated by the fact that both the AFL-CIO and the American Civil Liberties Union, "strange bedfellows" according to the judge, entered the case on the Christian Coalition's side.

"This is an important victory for all citizen groups," said coalition president Pat Robertson. "It wasn't just for conservative Christians. This was for citizen participation."

"It is one of the worst defeats for the FEC in the history of the agency," said the group's former executive director, Ralph Reed.

Even so, the decision comes at a time when the group has been losing members, experiencing staff turmoil and struggling with millions of dollars in debt. And for the coalition itself, the ruling may have more symbolic than practical significance. After a lengthy battle with the IRS over its tax-exempt status, the coalition announced recently that it will split into two groups: a political committee that can work directly in federal elections and a nonprofit arm that will produce the voter guides.

The use of "issue advocacy" advertisements and mailings by outside groups has mushroomed since the FEC filed the lawsuit in 1996, and the lawyers said Green's view of how far groups can go in signaling their backing for particular candidates without crossing over the line would provide even more encouragement for such tactics.

"It is yet another setback for any attempt to control issue group advertising," said Democratic election lawyer Robert F. Bauer. In recent years, Bauer said, groups have gone through "a series of traffic lights" for issue ads. "Now, the yellow light is merging very distinctly into green."

The FEC, said GOP election lawyer Benjamin Ginsberg, "staked a huge amount on the Christian Coalition case. It was a showcase for their effort to try to bring issue advocacy under their purview. Losing that argument ought to suggest a more prudent course" in future cases.

FEC officials declined comment.

Green's ruling had two prongs. Like other judges, she took a very narrow view of what words constitute "express advocacy," saying that would only apply to an "explicit directive" that "unmistakably exhort[s] the reader/viewer/listener to take electoral action to support the election or defeat of a clearly identified candidate."

On the separate question of how far outside groups can go in "coordinating" their activities with campaigns, Green agreed with neither the Christian Coalition nor the FEC. She said the Christian Coalition was wrong in insisting that it could have as many conversations with campaigns as it wanted as long as the language it used in voter guides or other material did not cross the line into express advocacy.

But she also said the FEC took too strict a view in limiting outside groups' allowable contacts with campaigns. She said that to constitute illegal coordination, the campaign must either suggest the expenditure to the outside group or engage in "substantial discussion or negotiation" over such matters as its content, timing and location.

Election lawyers were divided about how to assess that portion of the ruling.

Fred Wertheimer, head of Democracy 21, said the decision establishes that coordination between outside groups and candidates can be illegal -- a potentially important move. "The decision does not authorize outside groups to coordinate issue activity with candidates," he said. "The opinion clearly says that if you do coordinate, it's illegal."

But GOP election lawyer Jan Baran said the record of contacts between Christian Coalition aides and GOP campaign strategists was so extensive that it was unlikely any other dealings would be found to constitute illegal coordination.

"There's kind of a sense of, boy, if they didn't find coordination in this case, they're not going to find it with the AFL-CIO or environmental groups or the business groups that engage in issue advertising," Baran said. "So I think it has some potentially major consequences for the 2000 election."