North Liberty-based Heartland Express Inc. announced on Tuesday first-quarter net income of $19.7 million, or 23 cents per share, up from $16.6 million, or 19 cents per share, in the same quarter a year ago.

Operating revenues for the quarter fell slightly to $134.3 million from $134.8 million in the first quarter of 2012.

Operating income was positively impacted by a $7 million increase in gains on disposal of property and equipment, but negatively impacted by weather complications, the company said. Heartland Express is a trucking company.