Previous studies found small cash incentives prompted few people to quit
Bribing smokers with cash incentives helps them stop, US research suggests.
Smokers are three times more likely to kick the habit for at least six months when they are paid up to $750 (£520), a new study has found.
Nearly 900 General Electric workers took part in the test across 85 US sites. The results were published in the New England Journal of Medicine.
GE will launch a similar scheme in 2010 for all US employees, believing it will be cost-effective in the long term.
It aims to save some of the estimated $50m spent annually on extra costs for smoking employees.
The company believes it will get back what it spends over three to five years, through reduced illness and increased productivity.
Previous studies had indicated that smaller financial incentives had little effect on quitting smoking, said Kevin Volpp of the University of Pennsylvania School of Medicine, who led the research project.
"Incentive programs work if they're well designed and adequately funded," Mr Volpp told Reuters news agency.
"If you do a low-budget incentive program, it may have little effect."
"Our study shows that if you're able to get people smoke-free and keep them smoke-free for six months or more, there's a fighting chance they can stay smoke-free on their own," he said.
In the GE study, half the participants were given the financial incentive, while the rest were merely encouraged to join quit-smoking programmes.