US and Russian officials said the agents were being exchanged for four Russian citizens convicted of spying for the West.
A US administration official said what he called the quick and pragmatic arrangement of the spy swap spoke to the progress made in US-Russian relations.
Barack Obama, the US president, who met his Russian counterpart Dmitri Medvedev in the US last month, said after the talks that the two leaders had "succeeded in resetting" the sometimes difficult relationship between the two countries.
Rahm Emanuel, the White House chief of staff, told broadcaster PBS that Obama was aware of the investigation, the decision to go forward with the arrests and the spy swap with Russia.
Eric Holder, the US attorney-general, said the "extraordinary" case took years of work, "and the agreement we reached today provides a successful resolution for the United States and its interests".
The 10 US defendants, captured last week in suburban homes across the country, were accused of embedding themselves in ordinary American life for more than a decade while leading double lives complete with false passports, secret code words, fake names, invisible ink and encrypted radio.
|The 10 pleaded guilty to acting as unregistered agents of a foreign country [AFP]
The 10 pleaded guilty to conspiracy to act as an unregistered agent of a foreign country and were ordered deported.
Asked to describe their crimes in court on Thursday, each of the 10 acknowledged having worked for Russia secretly, sometimes under an assumed identity, without registering as a foreign agent.
An 11th defendant has been a fugitive since fleeing authorities in Cyprus following his release on bail.
But independent newspapers and liberal commentators in Russia have ridiculed the obvious lack of results from the spy ring and the apparent low level of the agents' training.
In any case, they are unlikely to be greeted as heroes in Russia, as the Kremlin will very likely try to quickly turn the page over the incident and avoid further damage in relations with Washington.
"Both sides want to put Cold War suspicions behind them," said Al Jazeera's Neave Barker, reporting from Moscow.
Still, the Russian government had promised Vicky Pelaez, one of the convicted 10, $2,000 a month for life, housing and documents to allow her children to visit Russia and have all their expenses paid, her lawyer, John Rodriguez, said in court.
Pelaez said the promises did not induce her to plead guilty.
Jeff Stain, a "spytalk" columnist for the Washington Post, called the swap a "very special case".
"First of all, none of these people were charged with espionage to start with," he told Al Jazeera.
"It seems to be now a concocted arrest; not that they were not guilty but that the United States government decided that it wanted to get possession of people in Russia ... [in exchange for agents] who they had under surveillance for many, many years in order to make a trade. That's my guess after looking at this for several days now."
In Russia, the Kremlin said Medvedev had signed a decree pardoning four convicted foreign spies so they could be exchanged for the 10 convicted in the US.
Among those pardoned, according to the Kremlin statement carried by Russian news agencies, was Igor Sutyagin, an arms-control expert sentenced to 14 years in prison in 2004 for spying for the US.
The Russian foreign ministry issued a statement saying that the exchange being conducted by Russia's Foreign Intelligence Service (SVR) and the CIA was conducted in the context of "overall improvement of the US-Russian ties and giving them new dynamics".
"That agreement gives grounds to believe that the course set by the leaders of Russia and the US will be implemented and attempts to derail it will fail," it added.
Medvedev's spokeswoman Natalia Timakova said in the statement that together with Sutyagin, Alexander Zaporozhsky, Gennady Vasilenko, Sergei Skripal - all Russian citizens - had been pardoned after admitting their guilt and submitting a plea for pardon.
Russian rights activists welcomed Sutyagin's release, but Amnesty International (AI), the London-based human rights advocacy group, has said that any deal requiring Sutyagin to leave Russia against his wishes would amount to forced exile, which is prohibited under international law.
"It will also deprive him of the chance to clear his name of the charges," Nicola Duckworth, AI's Europe and Central Asia programme director, said.
Sutyagin has insisted on his innocence, saying that the information he provided to a British company that investigators said was a CIA cover, came from open sources.
His family said this week that Sutyagin said he was forced to sign a confession, although he insisted he was not guilty and does not want to leave Russia.
Two other convicted agents on the Kremlin's swap list were Russian intelligence officers.
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 was sentenced to 14 years in jail in 2004 for spying for the US [EPA file]
Zaporozhsky, a former colonel in the SVR, quit the service in 1997 and settled in the US, but Russia enticed him back and arrested him in 2001.
He was sentenced in 2003 to 18 years in prison for spying for the US, convicted on charges of passing secret information about Russian agents working under cover in the US and about American sources working for Russian intelligence.
The identity of the fourth person on the list, Vasilenko, was unclear.
The US justice department said in a letter on Thursday that some of the four prisoners were in poor health and had served lengthy prison terms.
Preet Bharara, a US attorney, said the investigation against the spy ring in the US had been aimed at uncovering and deterring espionage, and "not undertaken for the purpose of having a bargaining chip".
He predicted the Russian government was "unlikely to engage in this methodology in the future and that's a good thing... The case sends a message to every other agency that if you come to America and spy on Americans in America you will be exposed".