(Adds details on ruling, request for comment, background)
SAN FRANCISCO, Oct 10 (Reuters) - Bayer AG's Monsanto unit was likely to get a new trial on the $250 million in punitive damages awarded by a jury to a groundskeeper who alleged the company's glyphosate-based weed killers, including Roundup, caused his cancer.
According to a Wednesday court filing in San Francisco's Superior Court of California, Judge Suzanne Bolanos was considering whether to grant the company's motion for a new trial on the punitive damages.
The judge's ruling, granting a new trial on the punitive damages, is tentative and was being discussed at a court hearing underway on Wednesday.
A jury on Aug. 10 found Monsanto failed to warn school groundskeeper Dewayne Johnson and other consumers of the cancer risks posed by its weed killers. It awarded $39 million in compensatory and $250 million in punitive damages.
Bayer, which faces more than 8,000 U.S. lawsuits over glyphosate allegedly causing cancer, has denied the allegations. It said decades of real-world application and scientific studies have shown the chemical to be safe for human use.
The judge said Johnson had failed to meet his burden of producing clear and convincing evidence of malice or oppression by Monsanto, a requirement for allowing a jury to award punitive damages.
Monsanto had asked Bolanos in court filings on Sept. 18 to set aside the entire verdict or, in the alternative, reduce the award or grant a new trial.
The judge's order said the company's request for an entire new trial that includes liability grounds will also be discussed during Wednesday's court hearing.
Bayer, which bought Monsanto earlier this year for $63 billion, did not immediately respond to a request for comment.
Lawyers for Johnson said they would only comment after Wednesday's court hearing concludes.
(Reporting by Jim Christie in San Francisco, writing by Tina Bellon in New York; editing by Bill Berkrot)