Manufacturing activity grew last month at the fastest pace in more than three years, a sign that the pace of the economic recovery is picking up, a private trade group said Monday.

The Institute for Supply Management, a trade group of purchasing executives, said its manufacturing index read 55.9 in December after 53.6 in November. A reading above 50 indicates growth.

Analysts polled by Thomson Reuters had expected a reading of 54.3.

A separate report on construction sounded a more cautionary note. Construction activity fell in November for a seventh straight month as spending on both residential and commercial projects declined. The 0.6 percent drop was bigger than the 0.4 percent decline that economists had been expecting.

Still, the ISM report said new orders, a signal of future production, jumped last month to 65.5 from 60.3 in November.

The index, which also includes production, employment, inventories and prices, first showed growth in August after 18 months of contraction. It has now shown growth for five straight months. December's reading is the highest since April 2006.

The manufacturing index's peak in the last decade was 61.4 in May 2004. It bottomed at 32.9 in the midst of the recession in December 2008.

Measures of manufacturing in the U.K., the eurozone and China also grew in December.