MONDOVI, Wis., April 16, 2013 (GLOBE NEWSWIRE) -- Marten Transport, Ltd. (Nasdaq:MRTN) today reported a 32.2% increase in net income to $7.2 million, or 32 cents per diluted share, for the first quarter ended March 31, 2013, from $5.4 million, or 25 cents per diluted share, for the first quarter of 2012. It was Marten's twelfth consecutive year-over-year increase in quarterly net income. Operating revenue, consisting of revenue from truckload and logistics operations, increased to $164.5 million in the first quarter of 2013 from $151.5 million in the first quarter of 2012. Operating revenue, net of fuel surcharges, increased 8.2% to $132.7 million in the 2013 quarter from $122.6 million in the 2012 quarter. Fuel surcharge revenue increased to $31.7 million for the first quarter of 2013 from $28.8 million in the 2012 quarter. Operating expenses as a percentage of operating revenue, with both amounts net of fuel surcharge revenue, improved to 90.6% for the first quarter of 2013 from 92.2% for the first quarter of 2012. Chairman and Chief Executive Officer Randolph L. Marten said, "We were able to demonstrate the strength of our multifaceted business model with a 32.2% improvement in net earnings for the quarter on an 8.6% increase in operating revenue. These gains were in large part driven by Marten Transport's continued strategic focus on customer solutions, cost efficiencies and improvements in equipment utilization, with disciplined execution reflecting the talent and teamwork of the people of Marten." Marten Transport, with headquarters in Mondovi, Wis., is one of the leading temperature-sensitive truckload carriers in the United States. Marten specializes in transporting and distributing food and other consumer packaged goods that require a temperature-controlled or insulated environment. Marten offers service in the United States, Canada and Mexico, concentrating on expedited movements for high-volume customers. Marten's common stock is traded on the Nasdaq Global Select Market under the symbol MRTN.