Following a spike in April, Class 8 truck orders fell 9.8 percent in May to 12,903 units for all major North American OEMs

, according to preliminary data released by FTR Associates. However, May order levels were still 74.7 percent above the levels of May 2009.

FTR slightly raised the annualized rate from 154,120 units to 154,836 units for May orders. This includes U.S., Canada, Mexico and exports.

"There was a spike in Class 8 orders in April, which we believed was un-sustainable in the current environment," said Eric Starks, president of FTR. "FTR's data shows that preliminary May orders as reported by the OEMs are still above the actual demand dictated by the fundamental issue of excess capacity throughout the industry. Our forecasts for the full year remain below the current annualized figures."

Final data for May will be available from FTR later in the month.