MOSCOW>> The U.S. and Russia orchestrated the largest spy swap since the Cold War, exchanging 10 spies arrested in the U.S. for four convicted in Russia in a tightly choreographed diplomatic dance today at Vienna’s airport.

The exchange was a clear demonstration of President Barack Obama’s “reset” ties between Moscow and Washington, enabling the U.S. to retrieve four Russians, some of who were suffering through long prison terms.

At least one of the four — ex-colonel Alexander Zaporozhsky — may have exposed information leading to the capture of Robert Hanssen and Aldrich Ames, two of the most damaging spies ever caught in the U.S.

Moscow avoided having 10 spy trials in the United States that would have spilled embarrassing details of how its agents, posing as ordinary citizens, apparently uncovered little of value but managed to be watched by the FBI for years.

After not commenting for days, the U.S. Justice Department in Washington finally announced a successful completion to the spy swap after the two planes involved touched down in Moscow and London.

One alleged Russian spy wanted in the United States — the paymaster for the whole spy ring — was still a fugitive after jumping bail in Cyprus. Neither the U.S. or Russia have commented on his whereabouts.

To start the whirlwind exchange, two planes — one from New York’s La Guardia airport and another from Moscow — arrived Friday in Vienna within minutes of each other. They parked nose-to-tail at a remote section on the tarmac, exchanged spies using a small bus, then departed just as quickly. In all, it took less than an hour and a half.

The swap completed, the Russian Emergencies Ministry Yakovlvev Yak-42 plane left Vienna for Moscow carrying the 10 people deported from the U.S., and a maroon-and-white Boeing 767-200 that brought those agents in from New York then carried four Russians who had confessed to spying for the West on to London.

British media said the U.S. charter landed at RAF Brize Norton air base in Oxfordshire in southern England, but it was not immediately clear what the plane’s next destination would be — if any.

Vienna added yet another event to its long history as a key Cold War diplomatic site, the capital of neutral Austria being a preferred place to work on treaties and agreements meant to reduce U.S.-Soviet tensions.

Both the U.S and Russia won admissions of crimes from the subjects of the exchange — guilty pleas in the U.S. and signed confessions in Russia.

In exchange for the 10 Russian agents, the U.S. won freedom for and access to two former Russian intelligence colonels who had been convicted in their home country of compromising dozens of valuable Soviet-era and Russian agents operating in the West. Two others also convicted of betraying Moscow were wrapped into the deal.

U.S. officials said some of those freed by Russia were ailing, and cited humanitarian concerns for arranging the swap in such a hurry. They said no substantial benefit to U.S. national security was seen from keeping the captured low-level agents in U.S. prisons for years.

“This sends a powerful signal to people who cooperate with us that we will stay loyal to you,” said former CIA officer Peter Earnest. “Even if you have been in jail for years, we will not forget you.”

The 10 Russian agents arrested in the U.S. had tried to blend into American suburbia but been under watch by the FBI. Their access to top U.S. national security secrets appeared spotty at best, although the extent of what they knew and passed on is not publicly known.

The lawyer for one of them, Vicky Pelaez, said the Russian government had offered her $2,000 a month for life, housing and help with her children — rather than the years behind bars she could have faced in the U.S. if she had not agreed to the deal.

U.S. officials had met Monday in Russia with the convicted spies and offered them a chance for freedom if they left their homeland, while Russian officials in the U.S. held similar meetings with the agents captured by the FBI.

Russian President Dmitry Medvedev signed a decree pardoning the four Thursday after officials forced them to sign confessions. The Kremlin identified them as Zaporozhsky, Igor Sutyagin, Gennady Vasilenko and Sergei Skripal.

Zaporozhsky, a former colonel in the Russian Foreign Intelligence Service, sentenced in 2003 to 18 years in prison for espionage on behalf of the United States. He was convicted on charges of passing secret information about Russian agents working undercover in the United States and about American sources working for Russian intelligence.

Skripal, a former colonel in the Russian military intelligence, was found guilty of passing state secrets to Britain and sentenced to 13 years in prison in 2006. He was accused of revealing the names of several dozen Russian agents working in Europe.

Sutyagin, an arms control researcher convicted of spying for the United States, asserts his innocence despite the confession. He worked with the U.S.A. and Canada Institute, a respected Moscow-based think-tank, before being sentenced to 15 years in 2004 on charges of passing information on nuclear submarines and other weapons to a British company that Russia claimed was a CIA cover. Sutyagin says the information he provided was available from open sources.

Gennady Vasilenko, a former KGB officer employed as a security officer by Russia’s NTV television, was sentenced in 2006 to three years in prison on murky charges of illegal weapons possession and resistance to authorities. It was not exactly clear why he was involved in the spy swap.

In exchange, the U.S. deported agents using the names Anna Chapman, Tracey Lee Ann Foley, Donald Howard Heathfield, Juan Lazaro, Patricia Mills, Richard and Cynthia Murphy, Vicky Pelaez, Mikhail Semenko and Michael Zottoli. All pleaded guilty on Thursday to conspiring to act as unregistered foreign agents.

Chapman, 28, whose active social life were splashed all over the tabloids, was accused of using a special laptop to transmit messages to another computer of an unnamed Russian official. Chapman is her married name, her maiden name was Kushchenko. She’s now divorced from a British man after four years of marriage who said his Russian father-in-law used to be a high-ranking KGB official.

Donald Heathfield and Tracey Foley were the aliases for Andrey Bezrukov and Elena Vavilova, who lived in Cambridge, Massachusetts, and had two sons, 20 and 16. She posed as a real estate agent around Boston, he worked as a sales consultant at Global Partners Inc., a Cambridge-based international management consulting firm and also had his own consulting company.

Another convicted couple, Mikhail Kutsik and Natalia Pereverzeva, had been living in Seattle and Arlington, Virginia, under the aliases Michael Zottoli and Patricia Mills. They had two children, ages 1 and 3.

Vladimir and Lydia Guryev, had been living in Montclair, New Jersey, under the names Richard and Cynthia Murphy. While he stayed at home with their two daughters, she had a well-paying job as a tax consultant in New York City.

Lazaro, 66, whose real name is Mikhail Vasenkov, brought his wife, Vicky Pelaez, into the conspiracy by having her pass letters to the Russian intelligence service on his behalf. She was a journalist for a Spanish newspaper in New York. Pelaez is her real name.

Semenko of Arlington, Virginia, worked at the Travel All Russia agency.

The fugitive who jumped bail in Cyprus after being arrested on an Interpol warrant is the suspected paymaster for the U.S. spy ring. Canadian authorities say he was traveling as Christopher Metsos, a 54-year-old tourist on a Canadian passport that stole the identity of a dead child. Authorities have not released any other identity for him and his whereabouts were not known.