Russia's entry into the World Trade Organization (WTO) will provide an important boost to European companies, the EU has said.
Russia is the EU's third biggest trading partner, with member countries exporting 108bn euros ($134bn; £85bn) of goods to the country, including 7bn euros worth of cars and 6bn euros of medicines.
Russia finally joined the WTO on Wednesday after 18 years of negotiations.
The country will now lower its import duties, limit its export duties and grant greater access to European companies. It will also introduce a host of other measures to bring it into line with WTO trading procedures.
All this should make the country with the biggest population in Europe a much more accessible - and predictable - market for foreign companies, says the BBC's Moscow correspondent Daniel Sandford.
Russia could also benefit greatly from joining, economists say.
It will get easier access to international markets and should see an increase in foreign investment. Russia currently exports 200bn euros of goods to the EU, of which 130bn euros is oil.
However, economists have warned that any improvement will also depend on Russia clamping down on corruption, reducing bureaucracy and improving the rule of law, our correspondent says.
Russia is the 156th member of the WTO. The Pacific island nation of Vanuatu, which also joined the organisation on Wednesday, is the 157th member.