VIENNA (AFP) – Russia and United States Friday staged their biggest spy swap since the Cold War at Vienna airport with 10 agents deported by US authorities and four imprisoned in Russia thought to have been exchanged.

Special Russian and US flights which took the spies to the Austrian capital took off within 15 minutes of each other after staging the dramatic swap.

In a statement, a source in the Russian intelligence services said: "The Russian citizens previously arrested in the United States have taken off on a Russian plane from Vienna for the motherland."

A US jet carrying the 10 members of a Russian spy ring caught in the United States arrived from New York and parked next to a Russian Emergency Situations Ministry jet believed to have brought four Russians jailed for working for Western nations.

The main doors to the two jets were hidden from media gathered at Vienna airport hoping for a sight of the glamorous Anna Chapman and a top Russian armaments expert who were among the group.

Vienna, near the old Iron Curtain frontier, has not seen such drama since the Cold War, when it was a traditional venue for espionage rivalry between the two superpowers.

Russia confirmed that a deal had been agreed with the United States aiming to end the spy scandal.

The Russian foreign ministry said the bargain involved the "return to Russia of 10 Russian citizens accused in the United States, along with the simultaneous transfer to the United States of four individuals previously condemned in Russia."

The United States sent back the 10 Kremlin agents late Thursday after they appeared in a New York court and pleaded guilty to acting as illegal agents for Moscow. They were immediately expelled.

The four released by Russia included Igor Sutyagin, who was convicted in 2004 of handing over classified information to a British company that Russia claimed was a CIA cover. He was serving a 15 year jail term.

President Dmitry Medvedev pardoned the four on Thursday after they signed documents admitting they had spied.

The case threatened to set back improving Russia-US relations but the Russian foreign ministry said its outcome showed that the "reset" spearheaded by Presidents Barack Obama and Medvedev was working.

"The current agreement gives us reason to believe that the course agreed by the leadership of Russia and the United States will be realised in practice and attempts to divert the sides from this course will not meet with success."

The Russian spies, all arrested June 27, included Chapman, whose semi-nude pictures and racy romances made her a global tabloid sensation.

"I hope that I will soon be able to see and embrace my daughter," Anna Chapman?s mother, Irina Kushchenko, told the news website.

Despite the diplomatic storm caused by the spy ring, the group appeared to have been amateurish and made little impact in the decade since being formed.

"No significant national security benefit would be gained from the prolonged incarceration in the United States of these 10 unlawful agents," State Department spokesman Mark Toner said.

In court, several of the defendants acknowledged using fake names. The defendants living as Richard and Cynthia Murphy were really Vladimir and Lydia Guryev, while Donald Heathfield's true name was revealed to be Andrey Bezrukov.

Peruvian-American journalist Vicky Pelaez, a firebrand columnist with New York's Spanish-language El Diario newspaper, gave a tantalizing hint of more James Bond-style activities, telling how she "brought a letter with invisible ink" to her contact.

Russia sent consular officials to the detained 10 to describe "the life these defendants might be returning to back in Russia," a US prosecutor said.

Alongside Sutyagin, the four released by Russia included Sergei Skripal, a former colonel with Russian military intelligence sentenced, ex-Russian Foreign Intelligence agent Alexander Zaporozhsky and Gennady Vasilenko about whom far less is known.

The last high-profile swap was in 1984, when US journalist Nicholas Daniloff was expelled from Russia the day before Gennady Zakharov, a Soviet official at the United Nations, came the other way after appearing for less than five minutes before a New York court.