IndyCar is searching for a new title sponsor after US telecommunications company Verizon opted to end its backing of the North American motor-racing series.
Verizon has held naming rights to the series since 2014 but the partnership will come to an end after the 2018 season.
Verizon replaced fashion brand Izod as the series’ title sponsor following the conclusion of the 2013 season.
Verizon will continue to serve as a primary sponsor of IndyCar outfit Team Penske.
Mark Miles, chief executive of Hulman & Co., the series’ parent company, said in a statement reported by the Autoweek website: “We truly appreciate the significant resources – both financial and technical – that Verizon has invested in IndyCar.
“Our series and sport have benefited across a variety of fronts as a result of our work together, and they have been great partners.”