General Motors has signed an initial agreement with unions to reduce its healthcare expenses by $3bn (£1.7bn) a year, sending its shares up 11%.
GM has seen its market share fall in its main US market
The jump in its share price came despite the firm also reporting a $1.6bn third quarter loss, compared to a $315m profit a year ago.
GM had long sought to reduce its expensive healthcare obligations, with talks starting back in the spring.
The US giant on Monday also reiterated plans to cut 25,000 jobs by 2008.
Detroit-based GM has been hit by falling sales in the US, where it has struggled against tough competition from Japanese rivals, and a decline in sales of sports utility vehicles.
GM's US business lost $1.6bn during the quarter and saw its market share slip to 25.6% from 28.5% a year ago.
Overall worldwide group sales totalled $47bn, up from $44.8bn for the same period in 2004.
GM Europe saw losses narrow in the quarter to $150m compared to $236m a year ago.