MILAN, April 8 (Reuters) - Proxy adviser Institutional Shareholder Service (ISS) recommended investors in Telecom Italia (TIM) to vote in favour of another mandate for the telecom group's CEO Pietro Labriola, a report prepared for TIM's shareholders meeting showed.

TIM investors are due to meet on April 23 to vote on the renewal of the board, with Labriola on a hunt for a second mandate as part of the slate of candidates put forward by the outgoing board.

Labriola has come under pressure following a record stock plunge last month after he unveiled the financial outlook for the business emerging from the sale of the former phone monopoly's domestic access network to U.S. fund KKR. (Reporting by Francesca Landini Editing by Chris Reese)