Before a CIA paramilitary team was deployed to snatch a radical Islamic cleric off the streets of Milan in February 2003, the CIA station chief in Rome briefed and sought approval from his counterpart in Italy, according to three CIA veterans with knowledge of the operation and a fourth who reviewed the matter after it took place.

The previously undisclosed Italian involvement undercuts the accusation, which has fueled public resentment in Italy toward the United States, that the CIA brashly slipped into the country unannounced and uninvited to kidnap an Italian resident off the street.

In fact, former and current CIA officials said, both the CIA and the Italian service agreed beforehand that if the unusual operation was to become public, as it has, neither side would confirm its involvement, a standard agreement the CIA makes with foreign intelligence services over covert operations.

Last Thursday, an Italian magistrate issued arrest warrants for 13 U.S. intelligence operatives. The warrants charged that they kidnapped a suspected terrorist, Hassan Mustafa Osama Nasr -- also known as Abu Omar -- held him hostage at two U.S. military bases and then flew him to Cairo, where he alleged to his wife in a phone call that he was tortured under interrogation.

The CIA "told a tiny number of people" about the action, said one intelligence veteran in the management chain of the operation when it took place. "Certainly not the magistrate, not the Milan police."

It is unclear how high in the Italian intelligence service the information was shared or whether the office of Prime Minister Silvio Berlusconi was aware. It was not shared with the magistrate issuing the warrants, who works independently from the national government.

The Italian court case offers an accidental glimpse into how U.S. and foreign intelligence agencies coordinate and communicate on sensitive counterterrorism matters in ways that are expressly kept secret, even from other parts of their governments. This bifurcation between stated policies and secret practices has become more common since the Sept. 11, 2001, attacks, as the CIA has sought cooperation from other governments to covertly apprehend and transport suspected terrorists to undisclosed locations without legal hearings.

The CIA has conducted more than 100 of these apprehensions, known as extraordinary rendition, since Sept. 11, according to knowledgeable intelligence officials.

In Italy, the justice department and public have been demanding answers from the United States and their own government since Nasr disappeared as he was walking to a mosque on Feb. 17, 2003. And justice departments and government investigators in other countries have begun to unearth information about their governments' roles in apprehensions once thought to be the work of the CIA alone.

In Sweden, an inquiry discovered that Swedish ministers had agreed to apprehend and expel two Egyptian terrorism suspects in 2002 but called the CIA for help in flying them out of the country when they could not charter a flight quickly to take the suspects to Egypt.

A former CIA official said the covert operation was exposed after the CIA paramilitaries drew attention to it by arriving commando-style, in semi-opaque masks, and "went through the standard drill as if they were arresting Khalid Sheik Mohammed," the architect of the Sept. 11 attacks.

In Canada, a government inquiry has revealed a greater role by Canadian intelligence in the Justice Department's secret 2002 "expedited removal" of a Syrian-born Canadian citizen to Syria after he was detained as he changed flights at a New York airport.

The CIA and a spokesman for the Italian Embassy in Washington yesterday declined to comment on the Milan case or this article.

Officials involved in the Milan operation at the time said it was conceived by the Rome CIA station chief, organized by the CIA's Counterterrorism Center, and approved by the CIA leadership and by at least one person at the National Security Council. The station chief has since retired but remains undercover.

The Italian operation was highly unusual even in the context of 100 renditions.

In most, if not all, other post-Sept. 11 renditions, the security service of the foreign country has apprehended the suspect, then transferred him into CIA custody. In the Italian case, operatives from the CIA's paramilitary branch, the Special Activities Division, were dispatched, making the risk of disclosure much higher.

Two of the CIA veterans said the operatives became directly involved because, by 2003, counterterrorism operations had become the main thing the agency's leadership and the White House cared about. "Everyone wanted into the game," a CIA officer said. "The CIA chief in Italy wanted to have a notch in his belt."

Current and former CIA officials offered conflicting accounts of whether anyone outside the Rome station chief's counterpart at Sismi, as Italy's military intelligence unit is known, was informed.

One U.S. government official involved with the operation said the Italians approved it "at the national level, among senior people."

But another CIA officer who reviewed the operation after it took place said it was highly unusual because "it should have been the head of service to the head of service" -- meaning then-CIA Director George J. Tenet speaking directly to his counterpart, Gen. Nicolo Pollari. "There's none of that . . . this is pretty abnormal."

Sometime after his apprehension on the night of Feb. 17, 2003, Nasr was secretly transported to Egypt, where he was detained on terrorism-related charges. When Egyptian authorities released him and placed him under house arrest, he called his wife in Italy, asserting that he had been tortured and describing his abduction. Nasr's whereabouts are unknown. People familiar with the case believe he is likely back in custody.

According to court records, the CIA operatives left paper and electronic trails that allowed Italian prosecutors and police to track their movements and associations as if they were pursuing an organized crime network, and to identify at least one CIA officer, the base chief in Milan, by his real name.

The chief left the country shortly after the operation was discovered, according to several CIA veterans. The paramilitary team and other CIA operatives who participated are also long gone, and it is highly unlikely the U.S. government would confirm their identities or extradite them for trial.

"They just won't be able to go back to Europe," quipped one CIA veteran.

Researcher Julie Tate contributed to this report.