By Abhinav Parmar

April 17 (Reuters) - Shares of U.S. trucking firms fell on Wednesday, after dismal quarterly numbers from JB Hunt Transport Services and Knight-Swift Transportation Holdings signaled a longer wait for a rebound in the freight industry.

Freight companies have been grappling with reduced transport volumes on account of a shift in consumer spending from goods to services, combined with global shipping delays.

In what TD Cowen analysts called an "ominous start for transport earnings", JB Hunt missed first-quarter estimates on Tuesday as it struggled with weak demand for intermodal services — its biggest segment.

Knight-Swift trimmed its profit forecasts for the first and second quarters earlier on Wednesday, blaming an oversupply of capacity in the trucking industry, disruption from frigid weather in January and increased pressure on freight rates with shippers trying to push down prices further.