"Not only a working group to examine the influence of the third energy package will be created, but also a working group on the road maps of Russian and European gas sectors until 2050," Medvedev told a gas conference.
He was referring to EU legislation, adopted in 2009, which orders the separation of gas sales and transportation businesses. The legislation also obliges companies to allow access to infrastructure to third companies.
The laws come into force next year, although the EU provides a two-year adaptation period.
Gazprom, which produces, pumps and sells gas, has lashed out at the legislation, saying it opposed further investment in pipelines it had built but which are supposed to be operated by other firms.
Medvedev said the implementation of the new EU rules may interrupt smooth gas supplies to Europe, citing the Opal pipeline, part of the North Stream project which will carry Russian gas to Europe under the Baltic Sea.
"It is not covered by third party access yet. But gas delivered from Russia to Germany cannot be supplied in full if the norms are used," he said.
Prime Minister Vladimir Putin, who on Saturday signed an agreement with Bulgaria on its stretch of the South Stream gas pipeline, said the third package implementation may lead to infrastructure restrictions and higher prices.
The European Commission said on Monday the Russian-Bulgarian deal should be changed so that EU states had access to the pipeline, designed to deliver up to 63 billion cubic meters of Central Asian and Russian gas via the Black Sea to southern Europe.