General Motors Corp. (search) is offering additional cash rebates on all 2005 vehicles sold on the U.S. market except the Hummer H1, in an effort to rid itself of year-end inventory, the company said on Friday.

The world's largest automaker said the $1,000 bonus cash offers will run through November 13.

Both Ford Motor Co. (search) and DaimlerChrysler AG's Chrysler arm are also offering additional rebates. The new offers follow significant drops in October sales amid falling consumer confidence and high gas prices.

Both GM and Ford reported 23 percent declines in monthly sales on Tuesday and industrywide sales slumped to their slowest pace in seven years.

"The reason for the bonus cash offer is a continuing sell-down of 2005 inventory," GM spokeswoman Deborah Silverman said. Some of GM's 2005 cars and trucks already offer discounts of up to $6,000. The new rebates would add to those offers.