Electric-plane startup Eviation Aircraft Ltd. says it has signed up two more customers for its pioneering commuter aircraft, taking the order backlog to more than 150 planes.

Both buyers are American and are recognized names in the aviation industry, Chief Executive Officer Omer Bar-Yohay said Thursday in an interview, declining to name them before formal announcements early next year.

Eviation’s plane, the Alice, is in the vanguard of a push into all-electric models, with the company betting its nine-passenger capacity and 650-mile range will attract environmentally conscious buyers in a commuter market served by a variety of light aircraft. Running costs will be about $200 per flight hour versus $1,000 for a turboprop, though the model will be slower than some conventional craft.

Eviation now expects its first flight next year rather than before Christmas as initially targeted, with U.S. Federal Aviation Administration certification slipping toward 2022, according to Bar-Yohay, who spoke in Tel Aviv, near where the company is based.

Battery Charging

Work is already taking place on installing charging infrastructure for initial customer Cape Air, a regional airline with operations in New York and New England that announced an order at the Paris Air Show in June, as well as on the U.S. West Coast for one of the new buyers, Bar-Yohay said.

Talks are underway with a fourth possible client in Australia, while the CEO has previously said that prospective customers include major U.S. carriers like United Airlines Holdings Inc. and JetBlue Airways Corp., which are interested in planes to feed their hubs.

The U.K. also represents a natural market, given its relatively small size and plethora of regional airports, Bar-Yohay said. The Alice would be well suited to Virgin Atlantic Airways Ltd.’s Connect arm—previously Flybe—which has an average flight time of 55 minutes. The executive was appearing with Virgin founder Richard Branson and CEO Shai Weiss at a technology conference.

Eviation has $200 million of funding from backers including Singapore’s Clermont Group, which bought at 70% stake this year, and needs a further $500 million to enter serial production. An initial public offering would be the preferred option, Bar-Yohay said.