Ford Motor Co.'s Twin Cities assembly plant will close on Dec. 19, marking the end of auto production in Minnesota for the automaker.

The Dearborn, Mich.-based company notified workers Monday. The factory makes the Ranger small pickup, a product with declining sales that Ford is discontinuing.

The facility has about 880 workers, Ford spokeswoman Marcey Evans said. That's about half the number five years ago when the automaker first announced plans to close the plant in 2008. Ford later extended the closing date to the end of 2011, rejecting a plea from former Gov. Tim Pawlenty and other officials to keep the facility open for good.

Officials of United Auto Workers Local 879, which represents assembly workers at the plant, could not be reached for comment Monday. Earlier this year, union leaders said Ford told them that the plant would close Dec. 22.

The shutdown coincides with the automaker's plan to drop the small pickup line in favor of its larger pickups. The Ranger, which peaked in popularity in 1999, is the only vehicle made at the St. Paul plant. The demise of the Ranger, the cost of retrofitting the factory to make other vehicles and its distance from Ford's industrial heartland were too much to overcome.

Ford has said it intends to market the 140-acre site next year but doesn't have specific redevelopment plans and doesn't have a date it will put it up for sale. Redevelopment of the site may prove complicated, experts say, because of contamination issues associated with years of manufacturing and a labyrinth of tunnels underneath the factory grounds.

After the shutdown, it will take six to 12 months to decommission the facility, which involves removing equipment and fluids stored in the plant and razing the buildings. Ford hasn't said what it will do with a separate two-story training center built in 1999 with big state subsidies.

"While we are sad to see their doors close, we are optimistic about the opportunity to use this land to create new businesses and jobs," said St. Paul Mayor Chris Coleman in prepared statement. "Through our partnership with Ford and a redevelopment framework in place, we will create new uses for this site that are of the greatest benefit to the region."

Attracted by cheap hydropower, Ford started building vehicles at the current St. Paul site near the Mississippi River in 1925. It converted to an all-truck assembly operation in 1978.

Susan Feyder • 612-673-1723