The European Union and Japan said on Friday that they had finalized a sweeping deal that would create a free trade area covering more than a quarter of the world’s economy, pushing against rising calls for protectionism in much of the West.

Leaders of both parties to the agreement trumpeted its strategic, as well as economic, importance. That it was announced just hours after Britain and the European Union broke a deadlock to start a new round of talks over that country’s withdrawal from the bloc only heightened its symbolic impact.

The so-called economic partnership agreement, which would be one of the largest free trade deals ever, “demonstrates the powerful political will of Japan and the E.U. to continue to keep the flag of free trade waving high,” the Japanese prime minister, Shinzo Abe, and the president of the European Union’s executive arm, Jean-Claude Juncker, said in a joint statement.

The deal is subject to ratification by lawmakers in Europe as well as Japan, but Mr. Abe and Mr. Juncker said that they were confident that once in place, it would “deliver sustainable and inclusive economic growth, and spur job creation.”