MOSCOW, October 5 (RIA Novosti) - All 14 political parties running in the Russian parliamentary elections have filed registration documents with the Central Election Commission bringing another stage of the election campaign to an end.

According to the Central Election Commission's schedule, all the candidate parties should have submitted election lists by October 5.

The pro-presidential United Russia party delivered its documents to the commission on Friday. It is the only party to have refrained from singling out three top candidates, with President Vladimir Putin heading its election list.

In addition, the party has registered the most number of candidates with 600.

The Central Election Commission has already approved federal election lists for the other top three parties running in the December elections.

The Communist party (KPRF) has 515 candidates, including its leader Gennady Zyuganov, Nobel Prize winner and parliamentarian Zhores Alfyorov and MP Nikolai Kharitonov.

The Liberal Democratic Party (LDPR) has 360 candidates on its list headed by leader Vladimir Zhirinovsky, an outspoken pro-Kremlin ultranationalist, Andrei Lugovoi, a Russian businessman, suspected by the U.K. of murdering ex-security officer Alexander Litvinenko, and Igor Lebedev, Zhirinovsky's son, who also chairs the LDPR faction in the State Duma.

The populist A Just Russia party, headed by upper house speaker Sergei Mironov, has registered 556 candidates. The party seeks to challenge the ruling United Russia party, but strongly supports Putin.

The Central Election Commission has already approved 10 out of 14 parties, including Patriots of Russia, the Union of Right Forces, Civil Force, the Greens, the Democratic Party of Russia, the Party of Peace and Unity and the Agrarian Party.

The commission should make a final decision on registering all candidate parties before October 28. Russia will hold parliamentary elections on December 2, 2007.