Marten Transport Ltd. (MRTN) on Tuesday reported a 5.4% increase in net income, to $8.4 million, or 25 cents per diluted share, for the second quarter of the year.

This fell short of Wall Street expectations, with a consensus forecast from Zachs Investment Research of 30 cents per share for the Wisconsin-based refrigerated truckload carrier.

The results compare to $7.9 million, or 24 cents per diluted share, for the second quarter of 2014.

These improvements were primarily due to the continued growth of its dedicated operations, according to the company.

For the six-month period ending June 30, net income increased 40.4% to $18.5 million, or 55 cents per diluted share, compared with $13.2 million, or 39 cents per diluted share, for the first six months of 2014.

Operating revenue net of fuel surcharges improved 6.1% to $143.9 million for the second quarter of 2015 from $135.7 million for the second quarter of 2014. It also moved 8.1% higher to $284.6 million for the first six months of 2015 from $263.2 million for the first six months of 2014.

Operating revenue including fuel surcharges was $163.6 million for the 2015 quarter compared with $168.4 million for the 2014 quarter, and was $324.9 million for the 2015 six-month period compared with $327.8 million for same time last year.

“We are encouraged by our continued growth in both our profitability and tractor fleet size, with our average truckload and dedicated tractor count up 201 tractors, or 9.2%, over last year’s second quarter,” said Chairman and CEO Randolph L. "Randy" Marten.

“Looking forward to the third quarter and beyond, we secured multi-year dedicated contracts for an additional 279 tractors in this year’s second quarter. We believe the demand for our customized dedicated transportation solutions will continue to result in further growth and remain confident about our position to capitalize on growth opportunities across all of our business units.”

More details on the company’s financial performance are available on the Marten Transport website.