* NATO orders out two Russian diplomats
* Action connected with case of Estonian official * Expulsions on same day as NATO-Russia formal ties resumed
By David Brunnstrom
BRUSSELS, April 30 (Reuters) - NATO has ordered the expulsion of two Russian diplomats over a spy scandal in which an Estonian official was jailed for passing secrets to Moscow, a NATO diplomat said on Thursday.
"Two Russian diplomats have been told they are not welcome here," the diplomat said, speaking on condition of anonymity. The pair were attached to the mission Russia has at NATO headquarters although it is not a member of the alliance.
The diplomat said they were expelled over the case of Herman Simm, an Estonian jailed for more than 12 years for treason in February for handing more than 2,000 pages of information to handlers in Russia's SVR Foreign Intelligence Service.
NATO ordered the diplomats out on Wednesday, the same day the alliance resumed formal talks with Russia at ambassadorial level, eight months after contacts were suspended over Russia's five-day war with Georgia last August.
Russia regards improving relations with NATO as part of a broader effort to improve relations with the West, and in particular with the United States. Ties with Washington sank to a post-Cold War low under U.S. President George W. Bush.
It was not immediately clear what impact, if any, the expulsions would have on attempts to improve relations.
The Financial Times newspaper said one of the expelled Russians was the son of Vladimir Chizhov, Moscow's ambassador to the European Union.
It quoted alliance sources as saying he and the other diplomat were attached to Russia's mission to NATO, and reported that they had worked undercover as intelligence agents.
Russian officials declined to comment and NATO spokesman James Appathurai said: "We do not comment on intelligence matters."
The Financial Times said the two expelled Russian diplomats were not directly involved in the Estonian spy affair, but NATO sources said the scandal had caused such damage to the alliance's security that it had to deliver a hard response.
Simm worked at the Estonian Defence Ministry from 1995 to 2006 and had access to top secret documents, including those related to NATO, which Estonia joined in 2004.
The case caused deep concern at NATO and was highly embarrassing for Estonia, a former Soviet-bloc state which views itself as a staunch ally of the West.
Estonian media said that information Simm passed to the Russians included documents relating to foreign countries' and international organisations' communication and information systems, data security, intelligence, counter-intelligence and defence policy.
Estonia quit the former Soviet Union in 1991 and, along with its Baltic neighbours Latvia and Lithuania, made integration with the West via NATO and the European Union a top priority. (Editing by Mark Trevelyan)