U.S. international containerized trade grew about 3.7% in 2011, a sharp slowdown from double-digit gains from the year before, according to preliminary figures from PIERS.

The improvement over 2010 was led by an estimated 5.8% year-over-year gain in export volume, according to the figures from PIERS, a sister company of The Journal of Commerce.

Containerized imports, measured in 20-foot-equivalent units, grew only 2.2% in 2011 over the year before, and most of that growth came early in the year. Final figures through the third quarter showed import volume contracted 1.6% in the three months ending Sept. 30, led by a 3.7% decline in imports from Asia.

For the full year, preliminary estimates from the PIERS numbers show U.S. imports from Asia growing a scant 0.1%.

The 3.7% gain in overall U.S. international ocean container volume follows an 11.8% year-over-year increase in 2010. But that gain also followed a steep drop in 2009, including a 15.1% decline in import volume.