While net orders of Class 8 vehicles fell 27 percent from June to July, ACT Research Co. says the slip is common around this season.

The publisher of new and used commercial vehicle industry data said July net orders were 11,667 units, compared to the 15,999 units reported in June.

"Normal seasonality accounted for about a third of the month-to-month decline in Class 8 net orders," said Kenny Vieth, partner and senior analyst with ACT. "The momentum in Class 8 demand is still increasing as trucking company profitability continues to rebound strongly."

Still, July orders were up 27 percent from July 2009, ACT said in the latest release of its State of the Industry: Classes 5-8 Vehicles.

In addition, July had to compete with June, which saw orders rise 93 percent year-over-year and 21 percent over May. This was the highest level this year, ACT said.

July net orders of medium-duty equipment increased over June, and compared to July 2009, medium-duty net orders were up 100 percent.

ACT publishes new and used commercial vehicle industry data, market analysis and forecasting services for the North American market, as well as the China market.