A former undercover CIA operative who sued Vice President Cheney and other top government officials for exposing her tie to Langley, Valerie Plame, is planning an appeal after a federal judge tossed the case out.

In a 41-page ruling yesterday, Judge John Bates concluded that the lawsuit was fatally flawed even if Ms. Plame and her husband, Joseph Wilson IV, could prove the existence of a high-level conspiracy to punish her for Mr. Wilson’s criticism of the White House’s statements on Iraq.

When they filed their suit a year ago, the couple claimed their constitutional rights were violated by Mr. Cheney, his former chief of staff, I. Lewis Libby Jr., and a top White House political adviser, Karl Rove. In September, after it emerged that a former deputy secretary of state, Richard Armitage, triggered the first published mention of Ms. Plame’s CIA connection, the couple added Mr. Armitage as a defendant in the case. “Obviously, we’re very, very pleased,” an attorney for Libby, Alex Bourelly, told The New York Sun yesterday. Libby’s defenders and other administration allies have deemed the lawsuit to be a political vendetta.

In a statement, Mr. Wilson, a former ambassador, said the legal fight would continue. “This case is not just about what top government officials did to Valerie and me,” he said. “We brought this suit because we strongly believe that politicizing intelligence ultimately serves only to undermine the security of our nation. … We are committed to seeing this case through.”

Judge Bates’s ruling rested primarily on the grounds that, while Congress has established a legal mechanism for addressing leaks of personal information, Ms. Plame and Mr. Wilson did not avail themselves of it. A law passed in 1974, the Privacy Act, allows lawsuits against federal agencies when officials expose private information in government files.

“It appears that plaintiffs could have stated colorable Privacy Act claims based on some of the alleged disclosures, particularly those involving information allegedly learned by Armitage from a State Department memorandum,” the judge wrote.

Lawyers for the couple argued that the Privacy Act was an awkward tool for use by Ms. Plame and Mr. Wilson because most courts that have considered the issue have ruled that the White House is not subject to that law. Judge Bates said the CIA and State Department were clearly subject to the law and that there was no requirement that the remedy Congress created be a perfect fit for every potential claimant. It is not clear why Mr. Wilson and Ms. Plame did not make Privacy Act claims in their lawsuit, which includes a wide range of legal claims against the defendants. One problem may have been a two-year statute of limitations in the Privacy Act that arguably had run out between the time of the leak in July 2003 and the time the suit was filed in July 2006. Another problem is that Privacy Act suits are filed against agencies, not individuals, and Mr. Wilson and Ms. Plame made clear they were seeking to punish those personally involved in the leak. It’s also possible that, because of the likely exemption for the White House, such a suit would have ended up focusing almost entirely on Mr. Armitage, who is not considered political and had a chilly relationship with the White House. That kind of an outcome may not have offered much satisfaction for Mr. Wilson, who once famously said he wanted to see Mr. Rove “frog-marched out of the White House in handcuffs” for his involvement in the leak.

Ultimately, one official, Libby, was charged and convicted, though for obstructing the leak inquiry and not for the actual leak. Earlier this month, President Bush commuted Libby’s 2 1/2 year prison sentence, though the four felony convictions, two years of probation, and a $250,000 fine were left in place.

Several administration officials, including Libby, Messrs. Rove and Armitage, and a former White House press secretary, Lawrence Fleischer, have acknowledged discussing Ms. Plame’s CIA tie with reporters. However, the officials have insisted that they meant no harm to her and did not know her job was classified.

In his ruling, Judge Bates evinced some discomfort with the tactics the officials allegedly employed against Mr. Wilson. “The alleged means by which defendants chose to rebut Mr. Wilson’s comments and attack his credibility may have been highly unsavory. But there can be no serious dispute that the act of rebutting public criticism, such as that levied by Mr. Wilson against the Bush Administration’s handling of prewar foreign intelligence, by speaking with members of the press is within the scope of defendants’ duties as high-level Executive Branch officials,” the judge wrote. The job-related nature of the alleged actions required the dismissal of another of the couple’s claims regarding publication of “private facts.”

The judge also expressed concerns that any litigation over the issue could expose secrets about Ms. Plame’s duties or those of other CIA operatives. Judge Bates, a longtime government lawyer who was once a deputy to a well-known independent counsel, Kenneth Starr, was appointed to the bench by Mr. Bush in 2001.