VATICAN CITY -- A U.S. judge in Texas dismissed Pope Benedict XVI from a civil lawsuit accusing him of conspiracy to cover up the sexual abuse of minors by a seminarian, ruling Thursday that the pontiff has immunity as a head of state.

U.S. District Judge Lee Rosenthal cited a motion filed by the Justice Department, known as a "Suggestion of Immunity," in which the government said allowing the lawsuit to proceed would be "incompatible with the United States' foreign policy interests."

"After a suggestion of immunity is filed, it is the court's duty to surrender jurisdiction," Rosenthal wrote.

Joseph Ratzinger -- Benedict's former name -- is named as a defendant in the civil lawsuit, accused of conspiring with the Archdiocese of Galveston-Houston and some of its officials to cover up the abuse of three boys during the mid-1990s. The lawsuit seeks unspecified monetary damages.

The three boys, identified in court documents as John Does I, II and III, allege that a Colombian-born seminarian on assignment at St. Francis de Sales church in Houston, Juan Carlos Patino-Arango, molested them during counseling sessions in the church in the mid-1990s.

Patino-Arango was indicted in May 2004 by a Harris County, Texas, grand jury on a felony criminal charge of indecency with a child and is a fugitive from justice.

Lawyers for one of the alleged victims argued in the lawsuit that a May 18, 2001, letter Ratzinger wrote to bishops around the world was evidence that he was involved in a conspiracy to hide Patino-Arango's crimes and to help him escape prosecution.

The letter, written when Ratzinger was prefect of the Congregation for the Doctrine of the Faith, explains that "grave" crimes such as the sexual abuse of minors would be handled by his congregation and that the proceedings of special church tribunals handling the cases were subject to "pontifical secret."

Daniel Shea, who is counsel to the lead attorney in the case, said Thursday that they were considering an appeal.

"I think it's a setback for the American people that the administration ever gave the Vatican diplomatic immunity to begin with, and that it's using that to shield them from the conduct that's involved in here," he said.

The pope's lawyer, Jeffrey Lena, said the ruling was significant in that Benedict was identified as "head of a foreign state, the Holy See." Some plaintiffs have sought to identify Benedict as only head of a religious entity.

Lena said Rosenthal's ruling recognized that "the pope is entitled to immunity like any foreign sovereign without any special limitations imposed upon his immunity just because he is a religious leader."