The St Petersburg city council has voted to extend Green Savoree Racing Promotions' license to organise the annual Verizon IndyCar Series event through 2020.

The city's managing director of development revealed that the race has had an economic impact of $48.3m and generates an estimated $5m in marketing value to the city, making it a valuable addition to the social calendar.

Under the amendment, the dates for the Firestone Grand Prix of St Petersburg have also been confirmed through 2018, with the 11-13 March race weekend set to be the 2016 season opener for both the IndyCar Series and its supporting Mazda Road to Indy development categories. The event will then be held over 9-12 March in 2017 and 8-11 March 8-11 in 2018.

"We would like to express our sincere thanks to mayor Rick Kriseman, members of city council and all city staff for their support and approval of this extension," said Kim Green, chairman and CEO of Green Savoree Racing Promotions, "The City of St Petersburg has a special place in the history of racing, and we look forward to running the Firestone Grand Prix of St Petersburg here for years to come."