MILAN, April 19 (Reuters) - U.S. investment company KKR

has sent European Union antitrust authorities a formal

notice about its proposed buyout of Telecom Italia's (TIM)

fixed-line access network, the former phone monopoly

said on Friday.

TIM said the confirmation it had received from KKR indicated

that the project was progressing according to schedule.

TIM has agreed to sell its domestic network to KKR for up to

22 billion euros ($23.5 billion) as part of a government-backed

plan aimed at cutting debt and relaunching the group.

TIM plans to finalise the deal around mid-2024 and any

delay could complicate the company's revamp.

Vivendi TIM's single largest shareholder with a 24%

stake, has criticised the network sale, questioning both the

price and the sustainability of the residual services business.

The French media group is fighting the sale in court.

The Italian government holds an indirect stake in TIM, which

has been weighed down by debt and has been battling fierce

competition.

($1 = 0.9376 euros)