Due to a deepening global financial crisis and plunging auto sales, Toyota Motor Corporation announced that it will freeze production at all 12 of its Japanese assembly plants for a total of 11 days during February and March. The work stoppage will follow a separate three-day production halt already set for January.

The carmaker cites an increasing number of unsold cars due to falling demand as reason for the disruption. “Dealer networks are reporting a serious backlog of cars that are just sitting on the lots,” a US Toyota spokesperson told HybridCars.com. “Very little inventory is moving. It’s unprecedented.”

Last month, Toyota predicted its first operating loss in 70 years of almost 1.7 billion dollars for the 2008 fiscal year (which ends in March 2009). Toyota’s projected profit for the upcoming year is $555 million, or approximately one thirtieth of the previous year—but that figure could be adjusted downward.

The Japanese production facilities will be suspended for six days in February and another five in March. If demand for conventional and hybrid vehicles continues to falter, more shutdowns are expected.