By Elvira Pollina and Giuseppe Fonte

MILAN (Reuters) – The board of Italian state investor CDP is due to meet later on Sunday to approve a multi-billion euro non-binding offer for the fixed network of former phone monopoly Telecom Italia, three people with knowledge of the matter said.

CDP has teamed up with Australian infrastructure fund Macquarie to bid for Italy’s most important telecommunications infrastructure, for which U.S. investment firm KKR has already presented an offer.

One of the people familiar with the matter said that CDP board members were set to meet at 3 p.m. (1400 GMT) to approve the offer.

In recent weeks, sources have told Reuters that CDP-Macquarie and KKR have both set an 18-billion-euro ($19 billion) enterprise value for TIM’s grid.

CDP’s offer would also involve TIM’s smaller fibre-optic network rival Open Fiber, which is owned by CDP and Macquarie and would be folded into TIM’s grid down the road.

KKR’s proposal, which rises to 20 billion euros when including a 2 billion euros earn-out, has given fresh impetus to efforts to revamp TIM after the failure of prolonged talks involving the government and TIM’s top two shareholders – CDP and France’s Vivendi.

Both figures are below the 31 billion euro price tag Vivendi has set to back selling the grid, for which TIM itself has indicated a valuation of 25 billion euros.

The grid’s sale to cut TIM’s 25 billion euro debt pile and offload half of its 40,000 domestic staff is a main plank of CEO Pietro Labriola’s push to reshape the group.

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

Under Italian rules, Rome has the power to block unwanted interest for assets of strategic importance such as TIM’s grid.

CDP’s bid is welcome because it makes the sale process more transparent, a senior government source said, but it leaves several scenarios open.

In its approach, KKR has left the door open to involving a state-run entity as a minority shareholder in TIM’s grid, but it opposes CDP playing such a role due to antitrust issues.

($1 = 0.9406 euros)

(Writing by Valentina Za; Editing by Louise Heavens and Emelia Sithole-Matarise)