Paolo Gabriele, Pope Benedict’s ex-butler, has been found guilty of stealing confidential papers from him and sentenced to 18 months in jail.
Prosecutors had called for a three-year sentence but it was reduced because of “mitigating circumstances”.
Speaking before the verdict, Paolo Gabriele said he acted out of love for the Church and did not see himself as a thief.
Paolo Gabriele had denied the theft charge but admitted photocopying documents and “betraying the Holy Father’s trust”.
His lawyer had asked for the charge to be reduced, but described the sentence as “good” and “balanced”.
Christina Arru later said she did not intend to appeal against the verdict, Reuters reported.
The agency quoted her as saying Paolo Gabriele was “serene” about his fate and “ready to accept any consequences”.
Paolo Gabriele is “very likely” to be pardoned by Pope Benedict, Vatican spokesman Federico Lombardi said, though it is not clear when this might happen.
The former butler was accused of stealing and copying the Pope’s documents and leaking them to an Italian journalist.
Official Vatican media have almost totally ignored the trial since it began and morning radio bulletins have omitted to mention the story.
The verdict was delivered after two hours of deliberation by the judges.
Presiding judge Guiseppe Dalla Torre handed down a sentence of three years, then cut it to 18 months on the grounds of Paolo Gabriele’s lack of a criminal record, his apology to the Pope and past services rendered to the Church.
The former butler will also have to pay court costs out of his own pocket.
Paolo Gabriele has now been returned to house arrest inside his Vatican apartment, where he has already been confined for several months.
The verdict brings to an end a week-long trial that has revealed an embarrassing breach of security at the highest levels of the Vatican.
On the last day of the trial, defence and prosecution lawyers gave their closing arguments, and Paolo Gabriele made a final appeal.
“The thing I feel most strongly is the conviction of having acted out of visceral love for the Church of Christ and of its leader on earth,” he said.
“I do not feel I am a thief.”
Christina Arru accused the Vatican police of irregularities and failures during their investigations.
She asked the court to reduce the charge to common theft or illegal possession, saying Paolo Gabriele had high moral motives although he had committed an illegal act.
Prosecutor Nicola Picardi had sought a three-year sentence, with an indefinite ban on Paolo Gabriele holding public office or positions of authority.
During testimony, the three judges presiding over the court heard how Paolo Gabriele used the photocopier in his shared office next to the Pope’s library to copy thousands of documents, taking advantage of his unrivalled access to the pontiff.
He would later pass some of them on to journalist Gianluigi Nuzzi.
In 2010 Gianluigi Nuzzi released a best-selling book, entitled His Holiness, largely based on the confidential papers and detailing corruption, scandals and infighting.
Its publication sparked the hunt for the source of the leaks inside the Vatican, leading to Paolo Gabriele’s arrest in May.
Police also told the court how they found thousands of documents at Paolo Gabriele’s home, including some original papers bearing the Pope’s handwriting. Some had the instruction “destroy” written by Pope Benedict in German on them.
Although Paolo Gabriele entered a not guilty plea, prosecutors say he confessed to taking documents during an interrogation in June, a confession he later stood by in court.
He told prosecutors he hoped to reveal alleged corruption at the Vatican, and believed that the Pope was being manipulated.
“I feel guilty of having betrayed the trust of the Holy Father, whom I love as a son would,” he told the court earlier this week.
The Holy See wants to see rapid closure of the scandal, as this weekend the Church is beginning what it calls a “year of faith”, a series of initiatives aimed at reviving Christian faith in formerly predominantly Catholic countries currently seeing creeping secularism.