IndyCar said Tuesday it is exploring partnerships with tire manufacturers besides Bridgestone Firestone, which has been the sole supplier for the series and under contract through the 2014 season.
Al Speyer, executive director of Firestone Racing, told Motorsport Magazine the company is interested in extending its contract with IndyCar through perhaps 2020, but has heard rumors that IndyCar is looking at other deals.
IndyCar CEO Randy Bernard confirmed that the series is looking at many different tire options and Firestone is not out of the mix.
"IndyCar is always exploring what's best for the sport for both the short and long term," Bernard said in a statement. "It is the series' goal to have partners that will provide safe, reliable and high-performance products that are designed to meet and exceed the on-track demands."
Speyer told the magazine Firestone is "deeply concerned" there is little the manufacturer can do but wait to see what IndyCar decides.
"Even though we thought they wanted to extend with us, all of a sudden we learned that they want to go in a different direction," he said. "It's clear to us the current IndyCar management is not interested in working with us. We want to stay. We've got certain rights and we want to stay. This new direction caught us by surprise. We had no idea it was coming."