Wires

UPDATE 1-California investigating Facebook, demands subpoenaed documents

Diane Bartz and David Shepardson

(Adds details from court document)

WASHINGTON, Nov 6 (Reuters) - California is investigating Facebook Inc's disclosure of user data to Cambridge Analytica and other partners, the state revealed on Wednesday in a court filing that demanded that the social media giant respond to its subpoena.

Revelation of the 18-month-old probe is the latest bad news for Facebook, which is already under investigation by 47 U.S. states. Some states, particularly New York and Nebraska, have raised concerns that Facebook and other big tech companies engage in anti-competitive practices, expose consumer data to potential data theft and push up advertising prices.

Facebook had no immediate comment.

Facebook investigations are part of a larger landscape of probes of big tech firms by the U.S. Justice Department and the Federal Trade Commission, as well as the House of Representatives Judiciary Committee.

California Attorney General Xavier Becerra's investigators asked the court to require Facebook to turn over information about developers and other third parties' access to data and changes in privacy settings for Facebook.

Becerras petition said the June 17 subpoena and interrogatories followed Facebooks initial responses and later news reports "concerning other claims of wrongdoing by Facebook over users' privacy. Facebooks responses to this second subpoena and set of interrogatories is patently deficient."

In particular, the attorney general's office pointed to a failure to look at communications of Facebook founder and CEO Mark Zuckerberg.

"Facebook has not searched the email of the company's chief executive and chief operating officers for documents responsive to the subpoena," according to the court filing.

(Reporting by Diane Bartz and David Shepardson; Editing by Lisa Shumaker)