Simona de Silvestro will return to the Indianapolis 500 in May with Andretti Autosport.

That was in question when de Silvestro signed with Andretti last month to compete in the Firestone Grand Prix of St. Petersburg hoping to attract sponsorship to run more races. But team owner Michael Andretti has secured sponsorship from global technology company TE Connectivity to put de Silvestro in a fifth team car for the 99th Indianapolis 500 on May 24.

Simona de Silvestro, who will be making her fifth Indy 500 appearance, is one of only three women to have a top-three finish in the IndyCar Series. AP Photo/David J. Phillip

Andretti and de Silvestro are in Philadelphia on Thursday for a 1:30 p.m. announcement.

"I'm so excited to be representing TE Connectivity at this year's Indy 500," de Silvestro said in a news release. "It's really great that they're partnering with me in my efforts during the Indy 500, and with their advance technologies in my Honda Indy car, I will for sure have one of the best opportunities to win during the month of May."

The Swiss-born de Silvestro, 26, was the 2010 Indianapolis 500 Rookie of the Year with a 14th-place finish and has competed in the race four times. She has one podium finish in the Verizon IndyCar Series -- a second at Houston in 2013 that makes her one of only three women to finish in the top three of an IndyCar race.

After spending last season as an affiliated driver with the Sauber Formula One team in Europe, de Silvestro returned to IndyCar last weekend at St. Petersburg. She was impressive in practice and qualifying, but after a series of misadventures, finished 18th Sunday.

"Simona did a great job for us in St. Pete, and we are excited to add her as a fifth Andretti entry for the Indy 500," Andretti said.

De Silvestro will join full-time Andretti drivers Ryan Hunter-Reay, the defending Indy 500 champion, and Marco Andretti and Carlos Munoz. Andretti also is fielding a car for former Formula One driver and IndyCar veteran Justin Wilson.

Today's announcement is taking place at the Franklin Institute, located in the heart of Philadelphia. De Silvestro will discuss STEM (Science, Technology, Engineering, Math) initiatives in racing with local junior high and high school students.

Andretti first announced a relationship with TE Connectivity in March. The company offers high-performance technologies, including connectors, sensors and cables.

De Silvestro competed in Andretti's No. 25 car at St. Pete and will transition to the No. 29 car beginning with oval-track testing of the new aero kits at the Indianapolis Motor Speedway on May 3. Indy 500 practice begins May 11; pole day is May 17.