Vivendi is currently at loggerheads with TIM's management over its plans to revamp Italy's biggest phone company's domestic business through the sale of its prized landline grid.

Some TIM directors sent a letter on Friday to urge the company to call a meeting as early as next week to select Luciano Carta to fill a vacant seat on the board, the sources said.

The nomination of Carta, a former chairman at Italian defence group Leonardo, is being sponsored by Vivendi.

TIM and Vivendi declined to comment.

One of the sources said Telecom Italia's nomination committee will start a review of Carta's candidacy on Monday, adding no board meeting has yet been called.

The board seat has been vacant since January when Vivendi Chief Executive Arnaud de Puyfontaine quit the board asking for a new governance set-up.

The French group, which owns a 24% stake in TIM, has called into question Chief Executive Pietro Labriola's plan to turn around the debt-laden company, centred on the sale of the grid.

TIM has set a deadline of June 9 to receive improved offers from rival suitors KKR and a consortium comprised by Italian state lender CDP and Macquarie for the grid.

In their latest bids, KKR and the rival consortium offered 21 billion euros ($23.12 billion) and 19 billion euros, respectively, for the asset, source have previously said, some 10 billion euros below Vivendi's price tag to back a deal.

TIM directors are expected to discuss the bids at an ordinary board meeting due on June 22.

($1 = 0.9084 euros)

(Reporting by Elvira Pollina; Editing by Mike Harrison)