MOSCOW — The Russian parliament voted Tuesday to ratify the country's accession to the World Trade Organization (WTO), capping 18 years of negotiations.

President Vladimir Putin had supported the move, albeit at times unenthusiastically. As a member of the global system designed to ensure free trade, Russia will have to dismantle its protectionist policies, but the goal is to attract more foreign investors with the new reassurance that rules will be obeyed and not subject to a capricious bureaucracy.

The vote in favor of ratification was 238 to 208, with opposition led by the Communists, who make up the second-largest group in the Duma, or lower house. They declared the nation's industry too vulnerable to survive without protections.

Russia does not expect that joining the WTO will, in the short run, help its exporters, because aside from raw materials Russia manufactures little that is in demand globally. Pork producers, who have been protected by a high tariff on live swine, expect to take a hit, as will rice farms. Other agricultural companies here, including those that produce oil seeds, should benefit, because Russia will have to eliminate export tariffs.