A U.S. judge is asking the Vatican to co-operate in serving the Pope and two other top officials with court papers that stem from decades-old allegations of sexual abuse by a priest in Wisconsin.

The request is an incremental — and long shot — step in a lawsuit that accuses the officials of conspiring to keep the allegations against a Milwaukee priest quiet. The Vatican is not obliged to comply with the request.

Under similar circumstances, the Vatican has made service difficult, time consuming and expensive by insisting, for example, that documentation be translated into Latin, one of the Vatican's official languages.

Mike Finnegan, lawyer for the Chicago-based plaintiff, said Friday he's not holding out hope that the Vatican reverses course and begins to co-operate now.

"Based on what they've done in other cases, I don't expect them to do the right thing," he said. "I expect more delay and obstruction."

A message left Friday with the Vatican's U.S.-based lawyer, Jeffrey Lena, was not immediately returned.

The lawsuit, filed in April in U.S. Federal Court, names as defendants Joseph Ratzinger, who is now Pope Benedict XVI; Cardinal Tarcisio Bertone, the Vatican secretary of state; and his predecessor, Cardinal Angelo Sodano.

It claims the three men knew about allegations of sexual abuse at a Milwaukee-area school for the deaf and called off internal punishment of the accused priest. Rev. Lawrence Murphy, who died in 1998, was accused of sexually abusing some 200 boys at the school from 1950 to 1974.

'Publicity stunt'

Lena has called the lawsuit a publicity stunt with no merit, and said it rehashes theories already rejected by U.S. courts.

The court order requesting the Vatican's co-operation was signed Sept. 24 by U.S. District Judge Rudolph Randa. It was released Friday by the Survivors Network of those Abused by Priests, or SNAP.

"The court requests the assistance described herein as necessary in the interests of justice," Randa wrote.

Plaintiffs in two other U.S. cases have also sued the Vatican under similar arguments. The three plaintiffs in the Kentucky case dismissed their case last month, and a case in Oregon is ongoing.

SNAP spokesman Arthur Budzinski called the Wisconsin court order a "hopeful sign."

He said he hoped it would lead to the Pope testifying directly under oath about what he knew about Murphy's actions when, as then Cardinal Ratzinger, he headed a powerful office that oversees the discipline of priests.