ROME, Jan 30 (Reuters) - Italy's Treasury and KKR KKR.N have agreed the terms of the bid to be presented by KKR for Telecom Italia's (TIM) TLIT.MI submarine cable unit Sparkle, three sources familiar with the matter said on Tuesday.

The offer is part of the broader agreement between private equity fund KKR and Prime Minister Giorgia Meloni's government to jointly take over TIM's fixed access infrastructure.

One of the sources, who comes from the Treasury, said the ministry "is ready" as it has finalised all the preparatory work for the bid, which requires Rome's backing.

TIM and KKR declined to comment.

Last month, TIM extended until Jan. 31 a deadline accorded to KKR for submitting a final offer on Sparkle, whose network extends over 600,000 km.

The offer is expected to be submitted by Wednesday's deadline, another source said, cautioning that deliberations are still ongoing.

Separate sources have previously said that KKR was working to submit a bid between 700 million euros ($758.38 million) and 800 million ($866.72 million) after TIM billed a 600 million euro offer as too low.

The Treasury will be able to take full ownership of Sparkle from KKR "at a later stage", under a decree adopted last year by Meloni's government.

($1 = 0.9230 euros)

(Reporting by Giuseppe Fonte and Elvira Pollina; Editing by Leslie Adler)

((giuseppe.fonte@thomsonreuters.com; +390680307711;))