Europe's sovereign debt crisis and other economic shocks are expected to slow the growth in global exports to just 3.7 percent in 2012, the World Trade Organization said Thursday.

That comes after a slowdown to 5 percent in 2011 and 13.8 percent in 2010, the global trade body said in its annual report. The figures represent the total volume of merchandise exported across borders, accounting for changes in prices and exchange rates.

The forecasts are nevertheless uncertain due to potential volatility caused by the eurozone crisis, U.S. debt concerns, economic aftershocks of the Japan earthquake and nuclear crisis, flooding in Thailand and the impact of continuing political unrest in the oil-rich Middle East. The estimates assume an oil price above $100 a barrel.

"More than three years have passed since the trade collapse of 2008-09, but the world economy and trade remain fragile," WTO chief Pascal Lamy said. "The further slowing of trade expected in 2012 shows that the downside risks remain high. We are not yet out of the woods."

The slowdown in 2012 would bring trade growth below the world average rate of 5.4 percent over the last 20 years, the WTO said.

In 2013, the growth rate is expected to rise slightly again, to 5.6 percent, the organization forecast. This was the first time the WTO predicted a growth rate more than a year in advance.

In 2011, developed countries did a bit better than expected, while the United States became a net exporter of fuels in large part because of coal exports to Japan, WTO officials said.

The United States saw exports grow 7.2 percent in 2011 after a rise of 15.4 percent the year before. The European Union saw exports grow 5.2 percent in 2011 after a rise of 11.5 percent the year before.

Japan's exports contracted by 0.5 percent, a sharp turnaround from its 27.5 percent rise in exports the year before, which had made up for the sharp 24.9 percent decline in 2009.

China, the world's biggest exporter, saw its growth in exports slow to 9.3 percent in 2011 after a surge of 28.4 percent the year before.

Measured in dollar terms, the total value of merchandise traded in 2011 was $18.2 trillion, a jump of 19 percent and an all-time global record driven by rising prices for fuels and other commodities.

The WTO, however, bases it forecast for growth rates on the volume of merchandise, since prices are difficult to predict.

The 2010 rate of 13.8 percent represented a slight downward revision to last year's reported figure of 14.5 percent — the biggest rise recorded since 1950 — based on more recent and complete data showing how economies rebounded from the global downturn.