WASHINGTON — Jeffrey A. Sterling, a former Central Intelligence Agencyofficer, was convicted of espionage Monday on charges that he told a reporter for The New York Times about a secret operation to disrupt Iran’snuclear program.

The conviction is a significant victory for the Obama administration, which has conducted an unprecedented crackdown on officials who speak to journalists about security matters without the administration’s approval. Prosecutors prevailed after a yearslong fight in which the reporter, James Risen, refused to identify his sources.

The case revolved around a C.I.A. operation in which a former Russian scientist provided Iran with intentionally flawed nuclear component schematics. Mr. Risen revealed the operation in his 2006 book, “State of War,” describing it as a mismanaged, potentially reckless mission that may have inadvertently aided the Iranian nuclear program.

On the third day of deliberations, the jury in federal court in Alexandria, Va., convicted Mr. Sterling on nine felony counts. Mr. Sterling, who worked for the C.I.A. from 1993 to 2002 and now lives in O’Fallon, Mo., faces a maximum possible sentence of decades in prison, though the actual sentence is likely to be far shorter. Judge Leonie M. Brinkema of Federal District Court, who presided over the weeklong trial, allowed Mr. Sterling to remain free on bond and set sentencing for April 24.

“This is a just and appropriate outcome,” Attorney General Eric H. Holder Jr. said. “The defendant’s unauthorized disclosures of classified information compromised operations undertaken in defense of America’s national security. The disclosures placed lives at risk. And they constituted an egregious breach of the public trust by someone who had sworn to uphold it. As this verdict proves, it is possible to fully prosecute unauthorized disclosures that inflict harm upon our national security without interfering with journalists’ ability to do their jobs.”

Edward B. MacMahon Jr., Mr. Sterling’s lawyer, said he would seek to get the verdict thrown out and, failing that, file an appeal.

“We’re obviously very saddened by the jury’s verdict,” Mr. MacMahon said in a telephone interview. “We continue to believe in Jeffrey’s innocence, and we’re going to continue to fight for him up to the highest levels.”

Bruce D. Brown, the executive director of the Reporters Committee for Freedom of the Press, an advocacy organization for journalists, said the Sterling conviction showed that forcing reporters to identify their confidential sources was unnecessary and ill advised.

“The speed with which the jury reached its verdict shows that reporter’s testimony was not needed for the government to make its case,” Mr. Brown said. “I think going forward this is going to be a powerful precedent.”

Liberal advocacy groups have hailed Mr. Sterling as a whistle-blower for taking his concerns about the program to the Senate Intelligence Committee in early 2003, a time when dissenting voices in the C.I.A. were hushed as the country prepared for war in Iraq. The Justice Department and C.I.A., however, deny that characterization. They said that the Iran operation had not been mismanaged and that Mr. Sterling had gone to Congress and then the news media as a way to settle personal grievances.

The Justice Department had no direct proof that Mr. Sterling, who managed the Iranian operation, provided the information to Mr. Risen, but prosecutors stitched together a strong circumstantial case. They described Mr. Sterling, who is black, as bitter and frustrated about what he believed was workplace discrimination. Telephone records and emails showed that Mr. Sterling and Mr. Risen had talked frequently, and prosecutors argued that only Mr. Sterling had the information, the motive and the opportunity to leak it.

“The defendant put his own selfishness and his own vindictiveness ahead of the American people,” Eric G. Olshan, a federal prosecutor, said during closing arguments Thursday. “For what? He hated the C.I.A., and he wanted to settle the score.”

The trial was part Washington spectacle, part cloak and dagger. Former Secretary of State Condoleezza Rice testified, as did C.I.A. operatives who gave only their first names and last initials, with their faces shielded behind seven-foot-high partitions. A scientist was referred to only by his code name, Merlin. His wife was Mrs. Merlin.

Officials revealed their preferred strategies for persuading reporters not to run sensitive stories. Jurors learned that, at the C.I.A.’s office in New York, employees could easily walk out with classified documents and never be searched.

Mr. Sterling’s lawyers said the government’s case was based entirely on suspicion. “The government has great lawyers,” said Barry J. Pollack, a defense lawyer. “It has a great theory. It just made a great argument. What the government lacks is evidence.”

Mr. Sterling’s lawyers argued that it was just as likely that Mr. Risen had learned about the operation from Capitol Hill staff members, then pieced together details from other sources at the C.I.A. and from the Russian scientist himself. Mr. Pollack acknowledged that Mr. Sterling had a relationship with Mr. Risen, but said they had talked only about Mr. Sterling’s discrimination lawsuit against the C.I.A. Mr. Risen probably asked about Merlin and the Iranian operation, Mr. Pollack said, but Mr. Sterling did not provide any information.

Mr. Sterling is the latest in a string of former officials and contractors the Obama administration has charged with discussing national security matters with reporters. Under all previous presidents combined, three people had faced such prosecutions. Under President Obama, there have been eight cases, and journalists have complained that the crackdown has discouraged officials from discussing even unclassified security matters.

Most of those charged since 2009 have pleaded guilty and avoided a trial. Of those, John Kiriakou, a former C.I.A. officer, is in federal prison, as are two former government contractors, Donald Sachtleben and Stephen Kim. Thomas A. Drake, a former National Security Agency official, cut a deal on a minor charge and avoided serving time.

The only other trial was the military court-martial of Chelsea Manning, the Army private formerly known as Bradley Manning, who was convicted and sentenced to 35 years in prison for providing a trove of government documents to WikiLeaks, the antisecrecy organization.

The most prominent leak case, however, remains open. Edward J. Snowden, a former N.S.A. contractor who downloaded and provided journalists with thousands of that agency’s documents, has fled to Russia to avoid criminal charges. Those documents revealed a domestic surveillance program in which the N.S.A. monitored the phone records of every American.

While the administration has defended the crackdown, Mr. Holder said he believed it went too far at times when it targeted journalists. Under Mr. Holder, prosecutors seized phone records from The Associated Press, labeled one Fox News reporter a potential criminal co-conspirator for inquiring about classified information and tried to force another to testify before a grand jury.

Mr. Risen’s lengthy fight to avoid testifying about his sources turned the case into a rallying point for news organizations, who said the Justice Department had made it harder to cover national security beyond what it released in news statements and approved leaks, such as those that told a glowing story about the mission to kill Osama bin Laden. Less favorable stories, such as those revealing warrantless wiretapping or secret prisons, led to criminal investigations.

The Supreme Court ultimately declined to hear Mr. Risen’s case, meaning he would have been forced to testify, and if he refused, he could have been put in jail. But Mr. Holder, in a reversal, said prosecutors would not force him to reveal his sources. With that option off the table, prosecutors opted not to call Mr. Risen to testify during the trial.