Europe should avoid more sanctions against Russia over its role in Ukraine and continue to pursue dialogue with Moscow, the chief executive of OMV, the longest-standing Western trade partner of Russian gas monopoly Gazprom, said.
The Austrian energy group signed its first long-term supply contract with the Soviet Union in 1968 and is a major importer of Russian gas.
"None of us can estimate what it would mean if no gas came from Russia to Europe, and if we cannot calculate the consequences we should not threaten it," Gerhard Roiss told Austrian ORF radio in an interview aired on Saturday.
The European Union is dependent on Russia for about a third of its oil and gas, and about 40 percent of the gas is shipped through Ukraine.
Two days after an international deal in Geneva to try to defuse the crisis in Ukraine, pro-Russian separatists have vowed not to end an occupation of public buildings. Washington has threatened further sanctions if the stalemate continues.
The U.S. and EU have so far imposed only targeted sanctions against a list of Russian and Ukrainian individuals and firms in retaliation for Moscow's seizure and annexation of Crimea from Ukraine last month.
Roiss said Europe needed a coordinated energy policy, especially to help countries such as Bulgaria and Slovakia, who are totally dependent on Russia for their gas supplies.
OMV's Nabucco consortium lost out last year in a contest to build a pipeline to bring new gas from Azerbaijan to Europe as part of an effort to diversify Europe's gas supplies.
The Nabucco West route would have travelled from Turkey to Austria through Bulgaria, Romania and Hungary.
"Europe learned little from the last crisis in 2009," Roiss said, referring to a dispute between Ukraine and Russia over gas supplies which resulted in supply disruptions in many European nations.
"It is important that there is a European dialogue with Russia on this subject."
Roiss urged Europe to think again about long-term strategic investments in energy infrastructure, including the production of gas within Europe.
Another Austrian industrial heavyweight, steelmaker Voestalpine's CEO Wolfgang Eder, said in an interview published Friday that Europe should consider allowing fracking for shale gas in sparely populated areas.