WAUWATOSA, Wis. — Briggs & Stratton Corp. announced a plan to close its Jefferson and Watertown factories in Wisconsin in fiscal 2010, leading to the loss of at least 430 jobs.

The plants, which are run by Wauwatosa-based Briggs & Stratton's power products division, currently manufacture all portable generator, home standby generator and pressure washer products marketed and sold by the company.

About 390 hourly production employees and 40 salaried employees will be permanently laid off as a result of the closing of the factories, Briggs & Stratton spokeswoman Laura Timm said.

An additional 90 to 100 salaried employees will be given an opportunity to transfer to other Briggs & Stratton facilities, Timm said.

Production at the plants will be consolidated into existing U.S. engine and lawn and garden product plants to "optimize plant utilization and achieve better integration between engine and end-product design, manufacturing and distribution," company management said in a statement.

"The market volatility for our weather-dependent products, along with the current economy constantly challenges us to find new ways to remain competitive," said Harold Redman, president of Briggs & Stratton's home power products group. "We continuously review our manufacturing footprint in order to achieve the greatest efficiency and utilization from the assets we employ."

Briggs & Stratton has available capacity at other locations and shifting work to those plants will make manufacturing more efficient, Redman said.

Portable generator production will be shifted to Briggs & Stratton's plant in Auburn, Ala., where engines for the generators currently are manufactured, she said.

The move also will put generator production closer to Atlantic coastal areas affected by hurricanes, Timm said. Sales of portable generators tend to rise during hurricane season.

Production of pressure washers will be moved to a Briggs plant in McDonough, Ga., Timm said.

The manufacturing of home standby generators, which are affixed permanently to a house to provide backup power, will be moved from Watertown to Briggs & Stratton's factory in Wauwatosa, she said.

The headquarters for Briggs & Stratton's power products group, which currently is located in Jefferson, also will be moved to Wauwatosa, Timm said.

The company will add a substantial number of jobs in Georgia and Alabama as a result of the shift in production. A minimal number of jobs will be added in Wauwatosa, Timm said.

"It will do more to preserve jobs there," she said.

Timm noted that demand for Briggs & Stratton's home standby generators has been weak.

Briggs & Stratton management met with employees in Jefferson and Watertown on Wednesday morning, Timm said.

"This decision wasn't made lightly," she said.

Affected employees will be offered a variety of outplacement services.

Briggs & Stratton management hasn't set an exact date for the layoffs and shifts in production, but it likely will come at the end of the current calendar year or in early 2010, Timm said.

A move won't occur before the end of this year's hurricane season, which concludes in late October, in order to ensure that there are no disruptions in production, she said.

"We don't know what this hurricane season is going to bring," she said.

In conjunction with the closing of the facility, the company will recognize a pre-tax $5.8 million charge in the fourth quarter of fiscal 2009 composed of $4.6 million of net asset impairments and approximately $1.2 million of employee-related charges for severance and pension costs.

The impact of the facilities' consolidation on fiscal 2010 earnings is projected to be minimal because estimated savings will be offset by closure costs and the fact that the facility will be in operation for a portion of the fiscal year. In fiscal 2011, the company estimates approximately $11 million of pre-tax savings from the consolidation of operations.