SAN FRANCISCO A U.S. judge on Friday ruled that Alphabet Inc’s self-driving car unit Waymo must disclose documents to attorneys representing Uber Technologies Inc [UBER.UL] about Waymo’s partnership with Lyft Inc, saying the information could be important in Waymo’s lawsuit accusing Uber of stealing some of its trade secrets.

Waymo claimed in a lawsuit earlier this year that former engineer Anthony Levandowski downloaded more than 14,000 confidential files before leaving to set up a self-driving truck company, which Uber acquired soon after.

Uber denies it used any of Waymo’s trade secrets. A trial is scheduled for October.

Waymo and ride-hailing service Lyft, which is a competitor to Uber, announced a partnership to get self-driving vehicles on the roads earlier this year.

As part of its litigation defense, Uber requested documents and other information about the deal from both Waymo and Lyft.

In a ruling on Friday, U.S. Magistrate Judge Jacqueline Scott Corley ordered Waymo to disclose due diligence documents over the deal, saying Uber could use them to assess Waymo’s argument that it suffered monetary damages from Uber’s actions. Corley said Lyft did not have to produce any documents.

A Waymo spokesman did not have immediate comment on the ruling.

Also on Friday, Waymo said it would dismiss three out of four patent claims it had filed against Uber, while maintaining one patent claim over a circuit for its laser technology.

U.S. District Judge William Alsup, who is overseeing the case, had previously said Waymo’s patent claims appeared meritless.

(Reporting by Dan Levine; Editing by Bill Rigby)