Putin, who will step down in May to give way to his chosen successor Dmitry Medvedev, will become prime minister. The position of chairman, which would offer strategic control over Russia's biggest party with an overwhelming majority in the lower house of parliament, could help Putin retain much of his power.
"We will today establish the post of party chairman... We earlier invited Vladimir Putin to join the party, and now we are proposing the post of chairman to him," Gryzlov, who is also speaker of the State Duma, told a party congress.
Gryzlov said it was "an important political issue," rather than a technicality.
Putin is expected to attend the party congress on Tuesday.
The Communist and the ultra-nationalist Liberal Democratic factions in the State Duma earlier approved of plans to propose Putin as chairman of United Russia.
Some analysts predict that Putin - Russia's most popular politician who has presided over eight years of economic growth and the country's reemergence as a key player on the world stage - will under any circumstances continue to hold the strings of power.
