An IBM spokesman told CNET News.com that the cases had been "concluded and dismissed", and refused to comment on whether a settlement had been reached.
The announcement follows two test cases earlier this year, which resulted in a verdict that the computer manufacturer was not responsible for the worker's cancers.
Former IBM workers Alida Hernandez, who suffered breast cancer, and James Moore, suffering from non-Hodgkins lymphoma, took IBM to court in November 2003 in an action designed to bypass California's state workers' compensation legislation. Normally workers are unable to sue their employers for damages but gain compensation through a different procedure under the state law.
Because Hernandez and Moore were seeking damages not just to compensate the harm they suffered, but also to punish IBM – known as punitive damages – the crucial issue in the case was what IBM actually knew. To win punitive damages, Californian law required the plaintiffs to prove that IBM knew that the chemicals were affecting its employees and that IBM hid that knowledge.
In the event the workers failed in that action, with the jury ruling that they had not been chemically poisoned while at work.
Around 240 other workers and families of former workers, most of whom were employed in IBM's semiconductor and disk drive manufacturing processes, have also filed lawsuits against the company, but all of the remaining California based claims have now been dismissed, according to reports.
The other suits, which will be based on the laws of different states, have yet to come to trial, although in March the computer giant settled a $100 million New York claim alleging that birth defects suffered by the daughter of former IBM worker Heather Curtis were caused by the chemicals that Curtis came into contact with at work.
IBM has always denied the claims, maintaining that it has done everything it could to provide a safe environment for its workers.