By BLOOMBERG

LUXEMBOURG • Facebook Inc’s messaging service WhatsApp was given a one month ultimatum by one of Europe’s strictest privacy watchdogs, facing an order to stop sharing user data with its parent without getting the necessary consent.

France’s data protection authority CNIL gave a sharp warning to WhatsApp by issuing a formal notice, criticising it for “insufficiently” cooperating.

The decision comes a year after European Union privacy authorities said they had “serious concerns” about the sharing of WhatsApp user data for purposes that weren’t included in the terms of service and privacy policy when people signed up to the service.

CNIL “decided to make this formal notice public in order to ensure the highest level of transparency on the massive data transfer from WhatsApp to Facebook Inc and thus to alert to the need for individuals concerned to keep their data under control,” the regulator said in a statement on its website on Monday.

Facebook faces regulatory hurdles throughout Europe over a range of privacy issues.

Germany’s Federal Cartel Office in preliminary findings published yesterday criticised Facebook’s data collection practices, saying the company abusively requires users to allow it collect data from web use beyond its site.

Menlo Park, Californiabased Facebook rejected the German authority’s findings as giving an “inaccurate picture”.

WhatsApp said that privacy is very important to it and that “it’s why we collect very little data, and encrypt every message”.