ROME (Reuters) - Italy is finalising the terms of a state-backed deal with semiconductor firm Silicon Box worth around 3 billion euros ($3.3 billion) to build an industrial site in the country, a source familiar with the matter said on Friday.

The move by Prime Minister Giorgia Meloni's administration is part of long-standing Italian efforts to attract investment from tech companies since a deal with U.S. firm Intel ( INTC ) has never been finalised.

Italy's Industry Minister Adolfo Urso has convened a press conference for next week to present what he called a "major new investment in Italy by a leading microelectronics company".

No further details were given, but the source told Reuters the deal would involve Singapore-based Silicon Box, an almost three-year old startup created by the founders of U.S chipmaker Marvell ( MRVL ).

Silicon Box focuses on 'chiplets', which can be the size of a grain of sand and are brought together in a process called advanced packaging, a cost-efficient way to bind small semiconductors to form one processor that can power everything from data centres to household appliances.

Asking not to be named, the source said the size of the investment as well as the amount of public money offered as part of the overall plan were yet to be finalised.

Silicon Box will build a production site in Italy, but it remains to be seen where as there are several sites across the country that are up for grabs, according to the source.

A spokesperson for the minister declined to comment. Silicon Box did not respond to calls and emails seeking comment.

Urso said last month that Italy was ready to offer 4.75 billion euros in state help to attract foreign chipmakers.

The minister has repeatedly said the Italian government would remain open to a possible investment by Intel ( INTC ), which has said it is still in talks.

Italy also held talks among others with Taiwan chipmakers MEMC Electronic Materials Inc and TSMC, Reuters had previously reported.

($1 = 0.9127 euros)