In December Vivendi, which owns 24 percent of Telecom Italia (TIM), called for the replacement of five of the board members put forward by Elliott, citing a "substantial lack of independence".

Vivendi's request was the latest twist in a months-long battle between Vivendi and Elliott over how to revive Italy's biggest phone group, an underperforming business saddled with 25 billion euros (£22.2 billion) of debt.

Another change in the board makeup could affect Elliott's ability to pursue a more radical shake-up of the telecom group which includes plans to spin off its network infrastructure, sell assets and convert savings shares into ordinary ones.

The U.S. hedge fund wrested board control from Vivendi in May by appointing 10 candidates - two-thirds of the total - to its board after accusing the French investor of serving its own interests. All candidates on Elliott's list were independent.

Elliott said Vivendi's request was its "latest effort to take back control of TIM and run the company for its own benefit", adding it remained open to a constructive dialogue with the top shareholder.

The fund also urged shareholders not to "turn the company back over to Vivendi" but instead give the new board and the new chief executive time to execute their strategy and create value.

Vivendi has asked for the removal of TIM Chairman Fulvio Conti and four other board members, Alfredo Altavilla, Massimo Ferrari, Dante Roscini and Paola Giannotti de Ponti.

It has proposed replacing them with five independent directors and said its aim is not to win control over TIM.

The list of board members to be replaced did not include the name of Luigi Gubitosi, who was among the candidates put forward by Elliott in May and who in November suddenly became TIM's new chief executive, succeeding Amos Genish, a Vivendi ally.

On Monday, two-thirds of TIM's 15 board members voted in favour of holding the shareholder meeting in March, a source familiar with the matter said, trumping a request by Vivendi for it to happen as soon as possible, preferably by mid-February.

The French media group said on Monday it "deplores the time-wasting tactics" used by the Elliott-nominated TIM board members, which it said were weighing on the group's performance.

"Vivendi reserves the right to request the convening of a new shareholders’ meeting this summer if the company's governance and financial results do not improve significantly," it added.

TIM said on Monday it had decided to bring forward a regular annual shareholder meeting on financial results scheduled for April and combine it with the one on Vivendi's requests.

The company hopes in this way to approve and disclose a new strategic plan and 2018 financial statements ahead of time to ensure shareholders have all necessary information.

In the strategic plan, likely to be presented in February, new CEO Gubitosi is expected to pursue the activist agenda proposed by Elliott which could be put into question were there to be another board overhaul.

Under former CEO Genish and with Vivendi's approval, the former state phone monopoly had been pursuing a three-year turnaround plan, focussed on digital transformation, fixing its finances and returning TIM to investment grade rating.

(Additional reporting by Alberto Sisto, editing by Louise Heavens, Susan Fenton and Jan Harvey)

By Agnieszka Flak