EU antitrust regulators are asking Microsoft’s rivals what kind of customer data they are required to provide to the US tech giant as part of their Azure cloud contracts, six months after a trade group complained about its cloud computing practices.

Cloud Infrastructure Services Providers in Europe (CISPE), whose members include Amazon, alleged last November that Microsoft’s new contractual terms imposed on Oct. 1 together with other practices were harming the European cloud computing ecosystem.

In a questionnaire sent to cloud providers seen by Reuters, the European Commission asked recipients for a list of contractual clauses requiring these companies to report information about their European customers to Microsoft.

“The Commission has received several complaints regarding Microsoft, including in relation to its product Azure, which we are assessing based on our standard procedures,” a spokesperson for the EU executive said.

The EU competition enforcer wanted to know about the frequency of the reporting, the period for which the data is requested, the format of the reporting and whether the information is sent directly to Microsoft or to an auditor.

Recipients, who were given until this week to respond, were asked whether there were contractual, actual or threatened consequences for not complying with these clauses.

The EU watchdog asked if Microsoft may have used the information to go directly to the recipients' customers.

Microsoft, hit by more than 1.6 billion euros ($1.8 billion) in EU fines in the previous decade for various antitrust violations, declined to comment.

It has made an offer to CISPE in a bid to settle the issue and talks are ongoing, according to a person familiar with the matter.