NORTH LIBERTY, Iowa, Feb. 4, 2014 (GLOBE NEWSWIRE) -- Heartland Express, Inc. (Nasdaq:HTLD) announced today financial results for the quarter ended December 31, 2013. Financial Results For the quarter, operating revenues increased 34.6% to $183.3 million from $136.2 million in the fourth quarter of 2012. Fuel surcharge revenues increased 30.3% to $36.5 million from $28.0 million in the fourth quarter of 2012. Operating income increased 8.1% to $26.7 million from $24.7 million for the fourth quarter of 2012. Net income increased 10.8% to $15.8 million compared to $14.3 million in the fourth quarter of 2012. Basic earnings per share increased 5.9% to $0.18 from $0.17 reported in the fourth quarter of 2012 on a 1.7% increase in weighted average shares outstanding mainly attributable to shares issued in the November 11, 2013 acquisition of Gordon Trucking, Inc. ("GTI"). For the quarter, the Company posted an operating ratio (operating expenses as a percentage of operating revenues) of 85.4% and an 8.6% net margin (net income as a percentage of operating revenues) compared to 81.9% and 10.5%, respectively, in the fourth quarter of 2012. Operating income for the three-month period was positively impacted by a $3.3 million increase in gains on disposal of property and equipment and a $2.3 million reduction in depreciation expense attributable to changing to the 125% declining balance method in the third quarter of 2013. As previously mentioned in the third quarter, the Company changed to 150% declining balance depreciation from historical 125% declining balance depreciation for tractors in 2009 due to lower used truck values, higher prices for new equipment, and uncertainty surrounding the reliability and resale value of tractors with 2010 emission-compliant engines. Effective, July 1, 2013, the Company changed depreciation for tractors back to the historical 125% declining balance method as a stable used equipment market supported a return to the Company's historical estimate of depreciation on tractor equipment over its expected useful life.