The case stems from Uber’s $680m (£542m) acquisition last year of Otto, a six-month old start-up launched by Anthony Levandowski, who previously worked at the Google project that became Waymo, the Financial Times reports.
Waymo has accused Levandowski and two others of stealing files containing its designs.
In a legal statement yesterday, Alphabet said: "Otto and Uber have taken Waymo’s intellectual property so that they could avoid incurring the risk, time and expense of independently developing their own technology.
"Ultimately, this calculated theft reportedly netted Otto employees over half a billion dollars and allowed Uber to revive a stalled program, all at Waymo’s expense."
Waymo is seeking damages and an injunction to stop Uber from using the allegedly stolen technology.
In a blog post, Waymo explained its version of events in no uncertain terms: "Our parent company Alphabet has long worked with Uber in many areas, and we didn’t make this decision lightly.
"However, given the overwhelming facts that our technology has been stolen, we have no choice but to defend our investment and development of this unique technology."