Commission Chairman Vladimir Churov said the Communists have 11.57%, the ultranationalist Liberal Democratic Party 8.14%, and the Kremlin loyalist A Just Russia 7.74%.
The remaining parties failed to get over the 7% threshold. The most successful of the other factions was the Agrarian Party which received a mere 2.3%.
Churov said the official results of the polls will be summed up on Saturday.
Central Election Commission Secretary Nikolai Konkin said earlier in the day that regional election commissions would submit protocols on Friday morning, with documents from just ten regions now available.
Under current laws, the results received from the elections federal automated system are preliminary and have no legal force until all protocols from regional election commissions are submitted.