By Crispian Balmer

ROME Entrepreneur Roberto Colaninno, chairman and CEO of scooter maker Piaggio and one of Italy's best-known dealmakers, has died, his investment company IMMSI said on Saturday.

He turned 80 last week. No cause of death was given.

Colaninno was a central figure in the country's industrial landscape who managed to turn around a number of failing companies, but also left a mixed corporate legacy.

He is most famous for his surprise $58 billion leveraged buyout of Telecom Italia in 1999, at the time the world's largest hostile takeover.

Many investors applauded him for masterminding the deal, but allies grew disenchanted over his plans to cut the debt mountain he had created, and forced him to sell control of the group to tyre-maker Pirelli just two years later.

While Telecom Italia struggled to recover from the debt burden that drained its finances for years, Colaninno emerged from the deal with a fortune of his own, enabling him to buy IMMSI, a telecom real estate business that he turned into an investment company.

In 2003, after his efforts to take over carmaker Fiat were rebuffed, he turned his attention to Piaggio, maker of the Vespa scooter, which had fallen on hard times.

He pulled it back from the brink, rapidly expanding its activities in Asia, especially India, China and Vietnam. The group posted record first-half results in July.

With Piaggio returning to profit, Colaninno looked to revive another struggling Italian icon, national carrier Alitalia, investing heavily in the airline in 2008 and becoming chairman in the process.

However, like many before him, he failed to turn the company around, and it was eventually shuttered. He was sent to trial last year along with 13 other defendants accused of fraudulent bankruptcy at the airline. He denied wrongdoing.

The case has yet to come to court.

Colaninno started his career at auto parts maker Fiamm, then hooked up with one of the giants of Italian business, Carlo De Benedetti. They founded a finance company, Sogefi, that bought Fiamm from its British owner and transformed it into one of the most successful car parts suppliers in Europe.

De Benedetti subsequently asked Colaninno to take charge of his floundering Olivetti company. Colaninno ditched the firm's loss-making computer unit and focused on the telephone business - which he subsequently used as a vehicle to launch the Telecom Italia bid.

He is survived by two sons, Matteo and Michele, and his wife Oretta.

(Reporting by Crispian Balmer; Editing by David Holmes)