Vladimir Putin served two terms as president before standing down
Russia's upper house of parliament has approved a bill extending presidential terms from four to six years.
The change to the constitution was backed by 144 members of the Federation Council. One senator voted against.
The bill was last week adopted by the lower house, the State Duma. It must now be supported by Russia's regional parliaments to become law.
The bill has been fast-tracked, and is seen by some as a sign Vladimir Putin may return to the presidency soon.
Mr Putin became prime minister this year after being obliged under the constitution to step down after two consecutive presidential terms. He was succeeded as president by Dmitry Medvedev.
Correspondents in Moscow says it has always been assumed that Mr Putin may return after Mr Medvedev has completed one term.
But the apparent rush to get this constitutional amendment through is being seen by some experts as a sign that Mr Putin is in a hurry and may return much sooner.
Then he could potentially serve another two six-year terms.
The bill also extends the mandate of the State Duma from four years to five.
The constitutional change will only apply to the next president and the Kremlin says it is needed because the existing four-year term is too short to implement serious reforms in such a huge country.