Eni's (E) Plenitude is under investigation by the Italian Competition Authority over "a suspected unfair commercial practice," the regulator said Friday.

The regulator said it "received many complaints" last year about the company's methods for informing consumers about the renewal of economic supply conditions, as well as "failure to implement measures to handle undelivered communications."

Consumers said their electricity and gas supply contracts were renewed with revised numbers without prior notice, denying them the right to withdraw, the regulator said.

Investigators, including officials from the Italian Financial Police's special antitrust unit, inspected Eni Plenitude's offices on Thursday, the regulator said.

Eni did not immediately reply to MT Newswires' request for comment.