Washington  - General Motors, under the government's gun to prove its viability and bracing for a worsening economic downturn, Thursday announced an unprecedented series of nationwide plant shut- downs over the summer aimed at reducing ballooning inventory.

The company said it would shut down 13 assembly operations in North America for multiple weeks, staggered across the summer, with the aim of removing 190,000 vehicles from the production schedule for second and third quarters of this year.

"We're taking aggressive steps to accelerate our inventory initiatives that have worked well since the first of the year," said Troy Clarke, GM North America president, in a statement.

He said the move aimed to "more closely align inventories with even more conservative market assumptions" and would "set ourselves up well for a clean 2010 model year start-up."(dpa)