Hertz Global Holdings Inc., barely four months out of bankruptcy, placed an order for 100,000 Tesla EV cars in the first step of an ambitious plan to electrify its rental-car fleet, according to people with knowledge of the matter.

It’s the single-largest purchase ever for electric vehicles and represents about $4.2 billion of revenue for Tesla Inc., according to the people, who asked not to be identified because the information is private. While car-rental companies typically demand big discounts from automakers, the size of the order implies that Hertz is paying close to list prices. 

“Electric vehicles are now mainstream, and we’ve only just begun to see rising global demand and interest,” Mark Fields, Hertz’s interim chief executive, said in a news release. “The new Hertz is going to lead the way as a mobility company, starting with the largest E.V. rental fleet in North America and a commitment to grow our E.V. fleet and provide the best rental and recharging experience for leisure and business customers around the world.”