MILAN, March 6 Reuters Telecom Italia TIM shares rose as much as 5 on Monday after Italian state investor CDP and Australian fund Macquarie submitted a joint bid for the former phone monopoly39;s grid, rivalling an approach by U.S. firm KKR.

TIM is betting on a sale of its most prized asset to cut its 25 billion euros debt pile and fund an overhaul of the revenuestarved group.

Both offers value TIM39;s grid, which is Italy39;s main piece of telecoms infrastructure, in the region of 18 billion euros 19.2 billion, sources familiar with the matter said.

The news is positive for TIM as a second approach increases its bargaining power, broker Equita wrote in a research note.

The shares were up around 3.5 at 0.32 euros at 0900 GMT, levels not seen since last April.

The government of Prime Minister Giorgia Meloni has repeatedly said it wants to win control of TIM39;s network while protecting jobs, but there is no common ground within the administration on how to reach that goal.

Regulation issues remain a hurdle for the new bidders, as CDP and Macquarie own TIM39;smaller rival Open Fiber. CDP owns also a 10 stake in TIM.

In its approach for TIM39;s grid, KKR, which already owns a minority stake in the former phone monopoly39;s network, left the door open to involving a staterun entity, but it opposes CDP playing such a role due to antitrust issues.

Both bids are below the 31 billion euro price tag sought by TIM39;s top investor Vivendi, whose support is key for any…