Hertz will spend $68 million to add the hybrid cars by 2008, the Park Ridge, New Jersey-based company said today. The first 1,000 will be available at U.S. rental sites within the next few weeks, spokesman Richard Broome said.

“We want to meet expanding demand for highly efficient vehicles,” Broome said in an interview. Hertz now has only “a few Priuses, a few Ford Escape hybrids” for U.S. customers, he said, without elaborating.

Rental-car companies are offering more fuel-efficient, low- emission vehicles amid record gasoline prices and increased concern among consumers about global warming. Avis Budget Group Inc., the third-largest U.S. rental-car company, said yesterday that it’s adding 1,000 Prius cars. Hybrids save fuel by combining a battery pack and electric motor with a gasoline engine.

Hertz’s Prius order is among the largest, though Toyota won’t say whether any company or government fleet has placed a bigger one. “It’s a very significant purchase,” Toyota spokesman Bill Kwong said, without elaborating.

Prius sales in May reached a record 24,009, making it the ninth best-selling vehicle in the U.S. last month. The company has said it expects to sell at least 180,000 this year, or 68 percent more than a year ago.

Closely held Enterprise Rent-A-Car, the largest U.S. rental-car company, last week announced a plan to offer vehicles that run on alternative fuels and said it had more than 3,000 gasoline-electric cars for rent. The company will take delivery of 1,300 Prius cars by the end of July, spokeswoman Lisa Martini said in an interview today.

The Green Collection is designed to appeal to a wide audiences and travelers and features such cars as the Toyota Camry, Ford Fusion, Buick LaCrosses and Hyundai Sonatas. These cars also carry the Environmental Protection Agency’s “SmartWay” certification, which is a certification given to cars that score 6 or better, on a scale of 0-10, on both the Air Pollution and Greenhouse Gas Scores, and have a total score when adding the two together of 13.

All the cars from the Green Collection are rentable directly from Hertz’s website at www.hertz.com or by calling 1-800-654-3131. Hertz’s environmentally friendly rental cars are noted as “Green”. Hertz guarantees availability of cars from its Green Collection at 50 major airport locations across the United States.

“Hertz now offers 42 specific makes and models that can be reserved by customers,” said Frank Camacho, Hertz Staff Vice President, Marketing. “We are pleased to be able to extend our vehicle selection program to include Fusion, Camry, LaCrosse and Sonata — a group of fuel-efficient cars that are suitable for families and friends,” he added. Camacho did not indicate whether Hertz had any plans to offer hybrid cars for rental.