Deminor, the shareholder activist group, is to turn to regulators before considering long-promised legal action over the $29bn (€26bn) merger of Telecom Italia and parent Olivetti amid growing doubts over court success.

The group plans to object to Consob, the Italian watchdog, and the US Securities and Exchange Commission in the US over procedural elements of the takeover. If that does not block the deal, Deminor said it would then challenge Olivetti's right to vote on the takeover under Italian corporate law.