With car making to ramp up in about four weeks at Volkswagen's Chattanooga plant, VW's local chief said Thursday his team is working to grow production with a potential new model.

But Frank Fischer, the plant's CEO, said it may be a while before the German automaker makes a decision.

"We're trying to do everything to make it happen," Fischer said, adding that a decision may not be made this year.

An auto website reported earlier this week that VW is planning a major expansion for its Chattanooga plant. A second phase could add 180,000 to 200,000 units a year to the plant's output, said Automobilemag.com. The factory initially will produce 150,000 cars a year at full operation.

Fischer told Chattanooga Rotarians the plant is to start producing the first cars for customers in about four weeks, and officials now are focused on launching the all-new VW Passat. The car will go on sale at dealers in the third quarter, the VW official said.

"We truly believe there is a lot of potential for growth," he said about VW sales in the United States. "We think our vehicle is coming at the right time."

The Dusseldorf native said the new compact Jetta unveiled last year is selling well, and the midsize Passat closes a gap in VW's product line in the U.S. The new Passat is designed for American motors-larger than the sedan it's replacing-and has the amenities U.S drivers want, according to VW.

The car continues to undergo endurance tests, and local officials are keeping up their daily drives of the initial vehicles made at the plant to improve quality, Fischer said.

"We really want to get it right," he said.

The plant's CEO also said VW is starting to hire a second shift at the factory.

Trevor Hamilton, the Chattanooga Area Chamber of Commerce's vice president of economic development, said VW has hired more than 1,400 people so far.

"It's always still quite amazing they still have 600 people to hire over the next 12 to 18 months," he said.

Fischer said the plant is being finished on time and within budget.

He said VW started work when the economy was in recession in late 2008, and the automaker's long-term view paid off.

"It was the right thing to do at the time," Fischer said.

PLANT TOURS

VW may open its new Chattanooga plant for group tours in October, an official said Thursday.