By Omar Abdel-Baqui 

Tesla Inc. Chief Executive Elon Musk said the electric-vehicle maker hasn't signed a deal with Hertz Global Holdings Inc. yet, which appeared to contradict a Hertz announcement late last month that the company was ordering 100,000 Teslas.

"I'd like to emphasize that no contract has been signed yet," Mr. Musk said in a tweet late Monday. "Tesla has far more demand than production, therefore we will only sell cars to Hertz for the same margin as to consumers. Hertz deal has zero effect on our economics," he said.

Representatives for Hertz and Tesla weren't immediately available for comment.

In late October, Hertz said it ordered 100,000 Teslas to be delivered to the rental-car company by the end of next year, a bulk purchase that promised to expose more mainstream drivers to Tesla's technology.

Hertz said last month it was "announcing a significant investment to offer the largest EV rental fleet in North America and one of the largest in the world. This includes an initial order of 100,000 Teslas by the end of 2022 and new EV charging infrastructure across the company's global operations."

Hertz in its statement said it was partnering with NFL quarterback Tom Brady to promote Tesla's EV campaign. The company's online press release included a video interview with Mr. Brady discussing his experiences with EVs.

Tesla didn't put out a press release when Hertz announced the deal.

Mr. Musk at the time tweeted: "Strange that moved valuation, as Tesla is very much a production ramp problem, not a demand problem." He added in a separate tweet: "To be clear, cars sold to Hertz have no discount. Same price as to consumers."

Tesla shares dropped 3.7% premarket. The stock has soared in recent days following the Hertz announcement, topping $1 trillion in market value. Mr. Musk's personal net worth also exceeded $300 billion in the days following the announcement and was recently $335 billion, according to the Bloomberg Billionaires Index.

Hertz shares have risen 38% since the Tesla deal was announced on Oct. 25.

Hertz had said that Tesla Model 3s would be available for customers to rent in some markets beginning in early November. It said electric vehicles would comprise more than 20% of its global fleet including the Tesla order.

Rental-car companies including Hertz have struggled to meet demand as post-vaccination travel ramped up and as a semiconductor shortage stalled vehicle production.

Write to Omar Abdel-Baqui at omar.abdel-baqui@wsj.com