MOSCOW (Reuters) - Russian Prime Minister Vladimir Putin said on Saturday that he would run for president in March 2012.
The following are key facts about Putin:
* Vladimir Vladimirovich Putin was born on October 7, 1952, in Leningrad -- now St Petersburg -- to working-class parents.
As a boy Putin took judo lessons and dreamt about joining the KGB, the Soviet Union's powerful security service. He studied law at St Petersburg State University and went to work for the KGB after graduating in 1975.
* Putin was a spy in Dresden in Soviet satellite East Germany from 1985 to 1990, giving him a front-seat view of the collapse of the Soviet empire. Its decline was to have a lasting impact on Putin, who later spoke about how he asked for orders from Moscow in 1989 but "Moscow was silent."
"I had the feeling the country no longer existed," Putin said in a book of interviews published in 2000. "The (Soviet) Union was ill. It was a deadly, untreatable illness called paralysis: the paralysis of power."
* Putin left Germany soon after the fall of the Berlin Wall and returned to his home town where he worked with mayor Anatoly Sobchak. In 1991, Putin was appointed chairman of St Petersburg's committee for external relations.
* After Sobchak was voted out in 1996, future Finance Minister Alexei Kudrin helped Putin get a job in the Kremlin.
Putin rose extremely fast through the ranks of the presidential administration: within six months of arriving in Moscow, he became deputy Kremlin chief of staff. By 1998 he was considered one of the most powerful officials in the Kremlin.
President Boris Yeltsin appointed Putin head of the Federal Security Service (FSB), the main successor to the KGB, in 1998 and in March 1999 he was given added responsibility as secretary of Russia's presidential Security Council.
Putin was made prime minister in August 1999 and was instrumental in launching a new war against Chechen separatists that increased his popularity.
Yeltsin unexpectedly resigned on December 31, 1999, making Putin acting president. Putin was elected to a four-year term as president on March 26, 2000, winning just under 53 percent of the vote, according to the official count.
Putin was re-elected on March 14, 2004, with 71.3 percent of the vote.
* As president, Putin sought to end the chaos which was the hallmark of post-Soviet Russia and he presided over the longest Russian economic boom in a generation, fueled by high market prices for oil.
Supporters credit Putin with bringing order and improving life for many Russians. Critics say he rolled back democracy and stifled freedoms of the post-Soviet era, and contend that his top-down style of government has done nothing to curb the corruption and government negligence.
During Putin's presidency, Russian nominal gross domestic product (GDP) grew from $200 billion in 1999 to $1.5 trillion in 2008 prices while the average monthly income grew from 1,500 roubles in 2000 to 15,000 roubles.
* As president, Putin increased centralized Kremlin control over politics and the economy and instituted liberal economic reforms drafted by his economic strategist German Gref. He won praise for introducing a flat income tax of 13 percent.
His economic reforms stumbled during his second term when Russia's fiscal revenues rose sharply due to high prices for oil and gas, Russia's main export commodities.
* Putin sought to curb powers of the business tycoons dubbed "oligarchs" and regional governors.
Critics say he drove the legal campaign against the owner of oil major Yukos, Mikhail Khodorkovsky. He is serving 13 years in jail following convictions for financial crimes in two trials the former tycoon's supporters say were politically motivated.
Putin's critics say the prosecution of Khodorkovsky and back tax claims that bankrupted Yukos were aimed to keep other tycoons in line and out of politics and to strengthen state control over Russia's oil riches.
* In the fiscal sphere, Putin largely backed the policies of Finance Minister Alexei Kudrin, who created a fund for windfall oil revenues and paid down most of Russia's sovereign debt.
Shedding Russia's reliance on aid and loans, a source of humiliation in the 1990s, was a big point of pride for Putin.
* Despite opposition from Kudrin, Putin loosened fiscal policy toward the end of his second term in office, allocating more money for infrastructure and social spending.
* Putin did not deliver on his promises to diversify the Russian economy away from the energy sector or reduce corruption, regarded as one of Russia's worst systemic problems.
* Contrary to Putin's promises to improve the investment climate, several corporate conflicts during his presidency led to major foreign firms losing out to their Russian partners in lucrative joint projects.
* A number of Putin's associates and friends became successful businessmen during the 2000s and some of Russia's richest people. Putin dismissed allegations that he enriched himself during his years in power.
* In foreign policy Putin attempted to improve relations with the United States when he telephoned U.S. President George W. Bush to offer condolences -- followed by support for the U.S. campaign in Afghanistan -- after the September 11, 2001, attacks.
The two remained on good personal terms, but the Russia-U.S. relationship deteriorated during Putin's presidency. Putin vehemently opposed the U.S.-led invasion of Iraq in 2003 and often accused the United Sates of meddling in sovereign states.
U.S. ties hit a low three months after the end of his presidency, when Russia fought a war with pro-Western Georgia.
* Putin has built good relationships with leaders of European Union powers such as Germany, Italy and France, as well as Turkey, all major consumers of Russian gas. But he has clashed with the European Union as a whole over energy policy and trade.
* Russia restored control over Chechnya in the war that helped catapult Putin to power in 1999-2000.
However, an Islamist insurgency stemming from the war has grown and Putin's presidency was marred by deadly attacks such as hostage-taking raids on a Moscow theater in 2002 and a school in the North Caucasus town of Beslan in 2004.
In both cases, Kremlin critics charged that bungled government responses caused many of the deaths.
Citing the need to consolidate society after the Beslan attack and two airplane bombings, Putin initiated a series of electoral reforms in 2004 that critics said curtailed democracy. The reforms included abolishing the election of regional governors.
Facing a constitutional bar on a third straight presidential term, Putin tapped Dmitry Medvedev as his favored successor, ensuring his victory in the March 2008 presidential election.
Putin was sworn in as prime minister a day after Medvedev's inauguration. On the next day he took the helm of United Russia, the ruling party that holds 315 seats in the 450-member State Duma lower parliament house and dominates government nationwide.
* Despite nominally being second in command, Putin remained the dominant member of what Russian officials call a ruling "tandem" with President Medvedev.
* As head of government, Putin spearheaded the response to the 2008-09 global financial crisis which hit Russia harder than other large emerging economies such as China, India and Brazil.
* Putin approved the so-called gradual devaluation of the rouble, which cost Russia about $200 billion from its gold and foreign exchange reserves but provided time for firms and households to convert roubles into foreign currency.
* Putin backed state aid and bailouts for corporations and stuck to a pledge to raise pensions. The budget is now expected to run a deficit until 2015.
* Putin publicly clashed with Medvedev over a March 2011 U.N. resolution that allowed Western military intervention in Libya, comparing it to "medieval calls for crusades." Russia abstained from the resolution.
* Putin has so far failed to achieve Russia's longstanding goal of joining the World Trade Organization and has stressed that Russia will join only if it is satisfied with the terms.
* In 2009 Putin took markets by surprise by announcing that Russia was freezing WTO accession talks and instead forming a Customs Union with Belarus and Kazakhstan. Russia has since resumed negotiations and is aiming to enter WTO this year.
* In May 2011, Putin launched an umbrella movement called the All-Russia People's Front in an effort to revitalize United Russia and improve its chances in the December 4 parliamentary election.
* During his years in power Putin has cultivated an action-man image with a series of stunts such as flying a supersonic jet, riding bare-chested on horseback or sitting astride a Harley Davidson motorcycle.
* At a congress of his United Russia party on September 24, Medvedev proposed Putin run for president. Putin said it was a great honor.
As Russia's most popular politician, Putin is almost certain to win a newly extended six-year term. He could also then run for another term from 2018 to 2024, a quarter of a century since he rose to power in late 1999. He would turn 72 on October 7, 2024.
Reporting by Gleb Bryanski and Guy Faulconbridge; Editing by Steve Gutterman and Robert Woodward