Ukraine's former Prime Minister Yulia Timoshenko is urging her one-time political allies to revive a reformist "Orange" coalition.
Ms. Timoshenko called Wednesday on allies of President Viktor Yushchenko to band together to prevent pro-Russia forces from returning to power in Kiev.
The pro-Russian opposition party of Viktor Yanukovych won the most seats in Sunday's parliamentary election, followed by Ms. Timoshenko's liberal bloc. President Yushchenko's party finished third.
No party won enough seats to form a new government on its own.
Meanwhile, Russia's President Vladimir Putin telephoned his Ukrainian counterpart Wednesday to pledge Moscow's commitment to cooperation with Ukraine.
The leaders of Ukraine's Orange Revolution got more votes combined than the Yanukovych party.
Ms. Timoshenko has expressed confidence that negotiations on a coalition will be completed in a week.
President Yushchenko fired her as prime minister last year in response to infighting in the cabinet, thus splitting the reformist movement.
Some information for this report was provided by AP and Reuters.