MOSCOW — President Vladimir V. Putin has ordered a major change in the rules for parliamentary elections, a move that could help solidify his power and influence toward the end of his current term and insulate him from dwindling public support for United Russia, the party that nominated him and currently holds a majority in Parliament.

At Mr. Putin’s direction, half of the 450 seats in the State Duma, the lower house of Parliament, would be filled using a proportional system based on votes for parties, with each party then filling its allotted seats. The other half would be filled by direct election of individual candidates, creating a potential opening for independent campaigns.

The new system, which the Central Election Commission is expected to unveil in the next several weeks, replaces a system of strict party-list voting. It would be the second major change to the parliamentary voting process in less than a decade and essentially amounts to a return to a system that had been in place through 2003. The proposal also comes just a year after allegations of widespread fraud in the parliamentary elections in December 2011 set off a wave of huge street protests in Moscow.

But while the prospect of individual candidacies suggests a liberalizing of a political system often criticized as heavily tilted in favor of Mr. Putin and the governing authorities, history shows that they can actually have the opposite effect.