San Francisco: Uber was hit with a $11.7 million ($US8.9m) fine by Colorado's public utilities commission Monday, after regulators found that dozens of drivers were operating there despite often egregious criminal histories.

In a press release detailing the fine, Colorado officials said that 57 Uber drivers over the past year and a half were on the job despite having felony convictions, major moving violations or were driving with a suspended, revoked or cancelled driver's license.

Uber said it is reviewing the fine. Credit:AP

The fine comes as the ride-hailing company continues to be battered by lawsuits for assault against its contractor drivers and struggles to polish a brand image that has been tarnished by a sexist corporate culture that toppled cofounder and CEO Travis Kalanick.

While Uber and other ride hailing companies do perform background checks on drivers, Colorado determined that despite having information that should have disqualified many drivers, Uber "allowed (them) to drive anyway," Colorado Public Utilities Commission director Doug Dean said in a statement.