Knight Transportation is keeping up its public campaign to buy rival truckload carrier USA Truck, despite being told the company is not interested in being purchased.

The Arizona-based Knight has announced that it has filed a presentation with the Securities and Exchange Commission in connection with its proposal to acquire USA Truck.

In a release Knight said it believes USA Truck’s recent financial results show “only limited improvement and that its recent share price surge is unsupported by either industry or company specific fundamentals.” 

“USA Truck’s truckload segment operating ratio remains above 100% and improved only modestly from 103.8% in the second quarter of 2013 to 103.6% in the third quarter of 2013,” Knight said in a release. “Knight continues to believe that USA Truck’s turnaround plan remains fraught with significant execution risk and notes that USA Truck’s limited cash flow generation has constrained its fleet investment, such that USA Truck now operates one of the oldest fleets among its publicly traded peer group, with an average tractor age of 2.5 years and average trailer age of 6.4 years.”

On Sept. 26, Knight proposed to acquire all of the outstanding shares of USA Truck for $9.00 per share in cash a premium of approximately 39% to USA Truck’s closing price on Sept. 25, the last trading day prior to public announcement of Knight’s proposal. 

“Knight continues to believe that its $9.00 per share, all-cash proposal fully and fairly values USA Truck, especially in light of USA Truck’s consistent underperformance, including nine consecutive quarters of losses totaling approximately $30 million,” says Knight.

The company says it “remains confident that its premium proposal is significantly more attractive than USA Truck’s standalone prospects, and Knight remains willing to modestly increase the proposed purchase price if USA Truck can demonstrate value that has not already been identified.

Last month USA truck responded to Knight’s purchase attempts filing a breach of contract lawsuit against Knight claiming it used USA Truck's confidential information to begin what it calls a “creeping hostile acquisition” of the Arkansas-based fleet.