The Communist Party will receive 57 seats, the ultra-nationalist Liberal Democratic Party (LDPR) 40, and the pro-Kremlin A Just Russia 38 seats in the State Duma, Vladimir Churov said.
With 99.8% of votes counted, United Russia, whose candidate list was headed by President Vladimir Putin, won a landslide victory of 64.2%. The Communists received 11.6%, the LDPR 8.1% and A Just Russia 7.7%.
"For the first three parties, the number of mandates is higher than they had in the previous Duma," Churov said, adding that A Just Russia formed in October 2006 had never been represented in the lower house before.
He said all four parties that made it into parliament were mass parties, each enjoying the support of at least five million people. The Central Election Commission issued around 109 million ballot papers for the election.
Churov said United Russia was a separate case because it had won the support of 45 million people.
According to the election official, parties to be represented in the new Duma gained a total of 91.7% of votes on Sunday.
"Very few foreign parliaments can boast such legitimacy when parliament represents nine tenths of voters," Churov said.
He said the election commission would finish counting votes by 14:00 Moscow time (11:00 a.m. GMT) on Tuesday, and repeated that the official results would be announced December 7-8.
