An auto industry analyst said Monday that making Porsche and Audi vehicles as well as Volkswagens at a possible U.S. plant is a cost efficient way of using a new facility.

“It wouldn’t be an unprecedented kind of thing,” said Paul Taylor, chief economist of the National Automobile Dealers Association.

German business newspaper Handelsblatt quoted Volkswagen sources as saying the company could run the plant together with its largest shareholder Porsche, according to Reuters.

It said the facility could make Porsche vehicles, Volkswagens and VW’s upscale Audi line as well, the report said.

Analysts have said Chattanooga’s Enterprise South industrial park would make sense for the new plant, which could eventually build 250,000 vehicles annually and employ some 2,000 workers.

J.Ed. Marston, the Chattanooga Area Chamber of Commerce’s vice president for marketing, had no comment on the report.

The 1,600-acre site in Tyner was a finalist for Toyota Motor Corp.’s latest North American plant that was awarded last year to Tupelo, Miss.

Other sites mentioned in reports for the potential VW plant are in Limestone County, Ala., near Huntsville, Ala., and Clarksville-Montgomery County, Tenn., northwest of Nashville.

Jim Bruce, president of an Atlanta-based company that helps automakers and other companies make decisions on locations, said the idea of producing upscale and middle-market vehicles in the same plant seems like a good one.

“There are some connections between the companies,” he said. “It’s not a situation where there’s an arms-length relationship. It sounds like a perfectly logical intuitive kind of thing.”

Mr. Bruce, president of Bruce Facility Planning Consultants, said automakers don’t want to lock themselves into producing just certain models.

“You want to design an auto plant to have flexibility and to be capable of providing a wide range of product and to change as the market changes,” he said.

Mr. Taylor said if auto assemblers are working off of the same vehicle platform, the sharing concept probably works better.

He said there is some platform sharing in the big crossover vehicle category between Volkswagen and Porsche, which maintains its U.S. headquarters in Atlanta.

“Both companies would gain efficiencies, but maintain a strong separate identify of two product lines,” Mr. Taylor said.

Martin Winterkorn, VW’s chief executive, also told the German newspaper it will decide before mid-July on whether to build the assembly plant.

“We will put the issue of the U.S. plant to the supervisory board before the summer break in July,” he said.

VW has said it is looking at Tennessee, Alabama and Michigan as sites for a new facility.