Hertz Corp.'s Donlen fleet management unit added double-digit growth to the company's non-rental segment in 2013 and showed strong fourth-quarter performance, Hertz reported on March 18.

Donlen added 12.5 percent more vehicles in 2013 by maintaining an average of 169,600 vehicles under lease and maintenance as compared to 2012. In the fourth quarter, Donlen maintained an average of 173,800 vehicles under lease and maintenance, which represented a 7 percent increase over the fourth quarter of 2012.

Donlen helped add 6.8 percent revenue growth to the company's non-rental segment in the fourth quarter. Hertz reported "other operations" revenue, which includes Donlen, at $134.9 million for the fourth quarter.

Overall, Hertz recorded 2.55 billion in fourth-quarter revenue, a 10.2 percent year-over-year increase. Worldwide, Hertz reported $10.8 billion in revenue in 2013, a 19.4 increase from 2012.