SAN FRANCISCO — Anthony Levandowski, a star engineer who helped build Google’s autonomous vehicle unit, pleaded guilty on Thursday to stealing trade secrets from the internet giant.

Mr. Levandowski left Google in 2016 to start his own autonomous vehicle company, which Uber quickly acquired. Waymo, the self-driving car business spun out of Google, sued Uber in 2017, claiming that Uber had bought Mr. Levandowski’s company as a way to acquire the information he had taken from Google. Uber fired him that year, and the companies settled the suit in 2018.

But scrutiny remained on Mr. Levandowski. In a separate case, Waymo accused him of illegally poaching its employees to work for him. And in criminal charges filed in August, federal prosecutors claimed that Mr. Levandowski had stolen more than 14,000 files related to the Google and Waymo autonomous vehicle program shortly before his departure. He was charged with 33 counts of theft and attempted theft of trade secrets from Google.

Mr. Levandowski pleaded guilty to one count of trade secret theft in an agreement with federal prosecutors to drop the remaining charges, according to a court filing. The plea carries a maximum sentence of 10 years in prison and a maximum fine of $250,000.