Earlier this month Prime Minister Giorgia Meloni's administration decided on a shake-up of Enel's board, signalling the end of long-standing CEO Francesco Starace's term.

Rome proposed Flavio Cattaneo, currently executive vice president of high-speed train operator Italo, to succeed Starace and Paolo Scaroni, a former Enel and Eni CEO, as chairman.

Shareholders including London-based hedge fund Covalis Capital and Mondrian Investment Partners complained about the board nomination process and demanded clarification about Rome's plans.

Proxy adviser firms Glass Lewis, ISS and Frontis Governance are expected to issue their voting recommendations next week, ahead of a shareholders' meeting scheduled for May 10.

In the meantime, two sources familiar with the matter told Reuters that Treasury representatives were holding talks on Thursday with proxy firms to clarify the nomination procedures and Rome's vision for Enel.

A Treasury spokesperson confirmed the talks, without giving further details.

Talks with investors are common practice, the spokesperson added.

One Enel investor, who did not want to be named, told Reuters it had sent letters to both the Treasury and the Italian government signalling it wanted the current board re-elected at next month's shareholder meeting and wanted confirmation of the group's strategy, but got no response.

"We have been left completely in the dark," the investor said.

Before the Treasury announced plans to shake up Enel's management, several other investors in Enel had told Reuters they wanted a CEO with expertise in renewables and strong international credentials.

($1 = 0.9142 euros)

(Reporting by Francesca Landini and Giuseppe Fonte; Editing by Susan Fenton)

By Francesca Landini and Giuseppe Fonte