Waymo's case against Uber over swiped self-driving car technology appeared headed for trial after an appeals court on Wednesday rejected a bid to steer it toward private arbitration.

A US federal appeals court upheld a lower court decision that an arbitration contract with a former Waymo employee at the heart of the case did not apply to the legal battle between Uber and the self-driving car unit of Google-parent Alphabet.

In a second potentially hazardous legal turn for the smartphone-summoned ride service, appellate judges also backed a ruling Uber had to turn over a potentially damning internal report to Waymo to be considered as possible evidence.

The trial was tentatively scheduled to start in San Francisco on October 10, pending any requests from the companies for a delay.

Uber early this year fired an engineer accused in the trade secrets suit, which involves files he purportedly purloined from Waymo.

The firing of Anthony Levandowski came just ahead of a date set by a judge for Uber to return files taken from Waymo.

Levandowski missed a company deadline for assisting with an internal investigation related to the litigation, according to an Uber spokesperson who asked not to be named.

The case stems from a lawsuit filed in February by Waymo, formerly known as the Google self-driving car unit, which claimed former manager Levandowski took a trove of technical data with him when he left to launch a competing venture that went on to become Otto and was later acquired by Uber.

Before Uber completed its purchase of Otto, lawyers for the firms retained Stroz Friedberg to investigate Otto employees who previously worked at Waymo, according to legal documents.

Attorneys for Levandowski had argued against a request by Waymo that the findings, referred to as "the Stroz Report," be handed over as part of the evidence discovery process in the case.

Waymo's lawsuit contends that Levandowski in December 2015 downloaded files from a highly confidential design server to a laptop and took the data with him to the startup.

"Waymo has supplied a compelling record that Levandowski pilfered over 14,000 files from Waymo, and that Uber knew or should have known as much when it brought him on board," US District Court Judge William Alsup said early this year while ruling on another matter in the proceedings.

Waymo argued in the lawsuit that a "calculated theft" of its technology netted Otto a buyout of more than $500 million and enabled Uber to revive a stalled self-driving car program.

Uber acquired commercial transport-focused Otto late last year as the company pressed ahead with its pursuit of self-driving technology.

Levandowski, a co-founder of Otto, headed Uber's efforts to develop self-driving technology for personal driving, delivery and trucking.

Source: AFP