Leaders of 15 Asia-Pacific countries plan to strike a regional free trade agreement on Sunday without India, creating an economic bloc representing around a third of the world's gross domestic product and population, sources familiar with the matter said Monday.

The members of the Regional Comprehensive Economic Partnership (RCEP) are hoping to sign the deal at a meeting of their leaders, putting an end to negotiations that began in 2013, the sources said.

It will be Japan's first signing of a free trade framework that includes China, its biggest trading partner, and South Korea. It is likely to benefit Japanese companies with manufacturing bases in the countries covered by the bloc.

India declared in November last year that it would not participate in the negotiations due to concern that opening up its market would cause its trade deficit with China to grow.

Besides India, RCEP groups Australia, China, Japan, New Zealand South Korea, and the 10 members of the Association of Southeast Asian Nations — Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam.