Any way you look at it, the United States and European Union will remain dominant players in world trade over the next two decades.

The real question, says the World Trade Organization in a new report, is how much ground they cede to rising economies like China.

The WTO's annual trade report says that under good economic conditions, China could increase its export share of manufactured goods to almost a quarter of global trade by 2035 while India's could more than double, to 5 percent.

The report Thursday says that under tougher conditions the EU and U.S. market shares would rise, but they would still lose in absolute terms because of a weaker economy.

In that case, it said, China and developing countries would lose market share.