CHATTANOOGA (AP) — Volkswagen is boosting production at its sole U.S. plant, though employees will have to spend fewer days a week to achieve that expansion.

The German automaker announced Tuesday that the plant that makes the popular Passat sedan will increase annual production by 30,000 cars next year.

"We will exceed what we had planned for 2012," said Frank Fischer, the CEO and chairman of Volkswagen Chattanooga. "Next year we are going to 180,000, and we feel very confident about it."

To prepare for that output, the facility's workforce has grown to 3,350 employees, who began working on a new production schedule this week.

Under the new system, workers will put in 10 hours per shift, but work only four days a week. The plant will be operational six days a week, for nearly 20 hours each day. Workers' preferences were taken into account for scheduling details ranging from break times to when shifts will start and end.

Fischer said the plant was not originally designed to operate as many days, but that it became possible under "a shift model we learned from other manufacturers."

The company said the new schedule is designed to cut down on overtime, maximize plant operations and help employees achieve a family-work balance.

Volkswagen AG, the world's second-largest car company, began building Passat sedans at the $1 billion plant last year. Volkswagen sold just under 23,000 Passats in 2011, an 83 percent increase over 2010.

Volkswagen, in two announcements earlier this year, said it would add 1,000 employees this year to ramp up production at the plant. The company conducted a national search to fill about 100 of the most specialized new jobs, using a national print and online advertising campaign to find top maintenance technicians, manufacturing engineers and logistics supervisors.

The new production target of 180,000 vehicles exceeds by 10,000 the number Jonathan Browning, the president and CEO of Volkswagen Group of America, projected at the latest jobs expansion announcement at the plant in March.

The company says the maximum capacity at the plant would be 220,000 vehicles before an expansion could take place. The layout of the facility would allow for another plant of the same dimensions to be built alongside the existing one, and officials have expressed hope that another model could be added to the Chattanooga site.

Most of the Passats made in Chattanooga are destined for the U.S. market, though VW also has expanded exports to Mexico, Canada, South Korea and the Middle East.