Andretti switched places with Alexander Rossi in the Andretti line-up ahead of the 2018 season and will stay in the #98 Andretti-run, Honda-powered car.

Earlier this year, Andretti told Motorsport.com that he understood his critics during a seven-year spell without an IndyCar victory.

Andretti has improved in 2018, taking his first pole since '13 in Detroit, and picking up five top 10 finishes during the current season. He ran close to a maiden podium of the year in Toronto before the team miscalculated his fuel strategy.

Andretti CEO Michael Andretti said: "It's great to be able to announce this extension for 2019 and beyond."

Marco Andretti says his continued target is to win the Indianapolis 500.

"I'm looking forward to continuing my IndyCar journey and am really hoping this next year is the one with an Indy 500 win, along with many others," he said.

Andretti was the only current driver to have his deal up at the end of 2019, and his new contract means he will remain in a line-up of Ryan Hunter-Reay, Alexander Rossi and rookie Zach Veach.

The 2019 season will be Marco Andretti's 14th in IndyCar.