(ANSA) - Rome, July 28 - Rome authorities will next week invite sponsors to fund the long-awaited restoration of the Colosseum, officials said Wednesday. A European advertisement will be published in Italy's Official Gazzette and two international newspapers on Friday August 4, they said.

"The restoration of the Colosseum is an historic event, important in the history of our country," said Culture Minister Sandro Bondi of the increasingly vulnerable 2,000-year-old symbol of Rome.

Rome Mayor Gianni Alemanno said the restoration would echo that of the Sistine Chapel and would extend from the Colosseum to "all the central archeological area" of Rome.

The mayor stressed that, during the work, sponsoring firms would not be able to put their names on the giant tarpaulin sheets masking the scaffolding.

Bondi and Alemanno are hoping to raise some 25 million euros from international sponsors. A consortium led by shoe mogul Diego Della Valle, an Japanese businessmen with shops in Rome and a Roman construction group is already reportedly talking to Alemanno about funding some of the work.

Pressure to get the project moving has risen since parts of an inside wall fell off in May.

Three thin slabs of the Colosseum's original mortar, together measuring about 0.5 square meters, came off the ground floor of the building and landed on an area where a show was in progress at about 6 a.m. on a Sunday morning, when there were no visitors.

But their impact was "partially cushioned" by protective netting that has been around several sections of the Colosseum since the 1980s, Culture Undersecretary Francesco Giro noted.

"The Colosseum is chronically ill. It's showing all the signs of its age, a natural, physiological disease," he said at the time.

Work can begin as soon as the government greenlights the tender, Alemanno said.

SPONSORSHIP 'IN STAGES', PERMANENTLY LIT-UP. Alemanno said recently the firms would each sponsor various parts of the project.

"Each entrepreneur will take a part, a ring of the Colosseum, to contribute to the 'relay'," the mayor said.

The complete restoration of the almost 13,000 square meters of exterior walls will take an estimated year to complete.

As well as the clean-up, unsightly barriers between the lowest arches will be removed and replaced by protective fences like the ones set up around the Roman Forum some years ago.

Then the monument, which is already lit up occasionally for special events, will get a permanent illumination system designed by a leading 'architect of light', Alemanno said.

The project will follow work under way to open up and make safe the Colosseum-topping attic, the third tier and, far below, the underground network of tunnels that took gladiators and wild beasts up to the arena.

New fire and security systems will be installed.

There will also be state-of-the-art metal detectors which, like the fence, will be positioned "at some distance" from the monument.

Alemanno called the planned project "epoch-making" and said it would make the monument safe for years to come.

The Colosseum would make "a leap" that will stave off all conservation concerns, he said, likening the project to the one that restored the Sistine Chapel from 1984 to 1994.

The Colosseum or Flavian Amphitheatre (its proper name) is perhaps the most attractive archeological venue in the world with some four million visitors a year.

Construction on the city's iconic monument started between 70 and 72 AD under the Emperor Vespasian.

It was completed in 80 AD by his son Titus, who financed the project from the booty his armies seized in the war against the Jews in 66-70 AD.