Formula E has set its sights on adding Fernando Alonso to the series in time for its fifth season.

Two-time world champion Alonso will leave Formula One at the end of the current season and looks set to take on some form of IndyCar commitment. The Spaniard completed an IndyCar test at Barber Park earlier this month and has said he will be ready to make a decision in October.

Alonso will also continue the rest of the World Endurance Championship super-season, which will culminate with the 2019 Le Mans 24 Hours -- an event he won with Toyota teammates Sebastien Buemi and Kazuki Nakajima earlier this year. With Alonso's immediate schedule after F1 looking busy, Formula E chief Alejandro Agag thinks it is more realistic the Spaniard would be available for the all-electric championship's 2019/20 campaign.

"I've been speaking with Fernando," Agag told the South China Morning Post. "Actually, I was with him in Monza, I think he's going to America this season, but definitely for the season after we are going after him.

"I speak with Fernando a lot, he likes Formula E a lot. He's very car-focused, Fernando. He's very curious about the new car that we are starting in Season Five. He wants to know more about that car and he think it looks very cool. Fernando is all about the car."

Fernando Alonso's future beyond 2018 looks set to be in series away from Formula One. James Moy Photography/Getty Images

Alonso's former Ferrari teammate Felipe Massa will join the Formula E grid for the 2018/19 season, which starts in Saudi Arabia in December. Massa will race for Venturi, spearheaded by new team principal Susie Wolff, Williams' former test driver.

Formula E will also welcome reigning F1 world champions Mercedes to the grid for the 2019/20 season, while it was able to lure Porsche away from its successful WEC programme. Agag believes the imminent changes show how big Formula E can be in the future.

"Massa is a great driver, he's a great friend, he's a really cool personality, and he has a big following all around the world. For him to drive in Formula E, it's great for the championship. We have a great line-up of drivers, second only to Formula One. Apart from that we are probably the best in the world.

"More drivers are doing fully Formula E, because of the growth - there are bigger budgets to pay the salaries so the drivers are exclusive. Formula E is becoming the priority.

"We want to go over a billion views for Season Five - we need to keep growing the reach of Formula E and get more fans. The championship is great, the technology is making huge steps, we've done all the things in the right order. I think as Formula E grows, everyone is paying more attention.

"Everyone thought this was going to be a short term venture, now it's really consolidated as a worldwide championship with all these big brands and car manufacturers.

"There was huge progress last season. We are far beyond our expectations. We signed a title sponsor, ABB, and announced a deal with Mercedes and Porsche, who left other championships to join Formula E. We have next year Nissan and BMW starting to race with teams.

"This championship is becoming huge. This grid, there's going to be a lot of power, not just in terms of electric."