Russia is widely expected to secure European Union approval to join the World Trade Organization at a summit on Tuesday, taking Moscow closer to completing membership negotiations after 17 years.

Russia's $1.2 trillion economy makes it the largest outside the WTO, and the World Bank has estimated entry could increase it by as much as 3.3 percent in the medium-term and 11 percent in the long-term.

President Dmitry Medvedev will meet EU leaders on Tuesday in Brussels at the 26th Russia-EU summit. The EU, which represents almost 500 million people, is Russia's biggest trading partner.

U.S. backing for Russian membership, as part of a broader so-called reset with the West, has been key in smoothing the path for Russian accession. Differences between the two powers had been a hurdle for years.

Prime Minister Vladimir Putin has said Russia hoped to join the 153-member WTO, which sets trade rules, in 2011.

Currently, the EU position carries decisive significance for the successful conclusion of the (WTO) talks in the swiftest manner, the Kremlin said in a statement last week.

Energy efficiency and climate change would also be discussed, said the Kremlin.

Russia's bid to join the WTO is the longest-running in history, and outstanding multilateral issues include the level of subsidy that Russia will pay its farmers -- a sensitive topic as WTO members try to cap agricultural support among themselves.

(Writing by Alexei Anishchuk, additional reporting by David Brunnstrom)