U.S. Xpress Enterprises today posted operating income that nearly doubled in the third quarter compared to a year ago, but the company's earnings fell just below analysts' expectations.

Operating income hit $22.9 million compared to $11.5 million in the third quarter of 2017, the company reported after the close of the stock market.

The Chattanooga-based trucking company reported it earned 33 cents per share in the quarter, missing the average estimate by analysts of 36 cents.

U.S. Xpress stock closed at $10.14 per share, up 51 cents, or 5.3 percent on the New York Stock Exchange, before the release of the earnings.

Eric Fuller, chief executive officer and president of the Chattanooga-based company, said the business is poised for record profits on the year.

"Based on the strong freight volumes, rate environment and the capacity currently being requested from our customers for the upcoming peak season during the fourth quarter, we feel well positioned to make 2018 the most profitable year in our history," he said.

The company posted operating revenue of $460.2 million, up 18 percent in the quarter.

Revenues were driven by an 11.2 percent increase in the company's rate per mile, a 54 percent hike in brokerage revenues to $65.1 million, and a $12.6 million rise in fuel surcharge revenues.

Net income attributable to controlling interest for the quarter was $16.1 million versus a net loss of $700,000 in the prior year quarter. That's the highest level of net income earned in a single quarter in the company's history, according to U.S. Xpress.

Fuller said U.S. Xpress is seeing results from company initiatives and a cultural overhaul as it experienced its fifth consecutive quarter of year over year improvements in its operating ratio.

"However, we are far from satisfied with our operating performance for the third quarter, as we believe our seated truck count and miles per tractor could have performed better had we executed more effectively during the quarter," he said.

Fuller said U.S. Xpress has taken steps internally to address the relevant issues and both average seated truck count and average miles per tractor per working day have increased in October compared with the third quarter.