(Adds European Commission deadline in headline and first paragraph)

By Elvira Pollina

MILAN, April 19 (Reuters) - U.S. investment company KKR's proposed buyout of Telecom Italia's (TIM) fixed-line access network will be decided by EU antitrust regulators by May 30, according to a European Commission filing on Friday.

The former phone monopoly said earlier on Friday that KKR had sought approval from the EU competition enforcer for the proposed deal.

The Commission can clear the deal with or without remedies during its preliminary review or it can open a four-month long investigation after the initial scrutiny if it has serious concerns.

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) (Reporting by Elvira Pollina Additional reporting by Foo Yun Chee in Brussels Editing by Jane Merriman and Frances Kerry)