Manufacturing grew in December at its fastest pace in six months, showing growth for the 29th consecutive month, according to the Institute for Supply Management,

a trade group of purchasing managers.

The institute's Purchasing Managers' Index registered 53.9%, an increase of 1.2 percentage points from November's reading of 52.7. A PMI in excess of 42.5%, over a period of time, generally indicates an expansion of the overall economy.

"Manufacturing is finishing out the year on a positive note, with new orders, production and employment all growing in December at faster rates than in November, and with an optimistic view toward the beginning of 2012 as reflected by the panel in this month's survey," said Bradley J. Holcomb, chair of the Institute for Supply Management Manufacturing Business Survey Committee.

U.S. manufacturing has expanded for more than two years, which has helped the trucking industry recover better than the overall economy. Manufacturing output generates a significant amount of truck freight.

The New Orders Index increased 0.9 percentage point from November to 57.6%, reflecting the third consecutive month of growth after three months of contraction. Prices of raw materials continued to decrease for the third consecutive month, with the Prices Index registering 47.5%, which is 2.5 percentage points higher than the November reading of 45%.

The nine industries reporting growth in new orders in December - listed in order - are:
* Printing & Related Support Activities
* Textile Mills; Apparel
* Leather & Allied Products
* Primary Metals
* Paper Products
* Machinery
* Computer & Electronic Products
* Food, Beverage & Tobacco Products
* Electrical Equipment, Appliances & Components.