An island in the Venice lagoon, a 15th century bastion against the Ottoman Turks and a former monastery on the southern coast are among prime properties Italy has put on an online auction for buyers from around the world.

Searching for funds to cuts its public debt and comply with European Union budget guidelines, the cash-strapped country has cut through red tape to ensure buyers can quickly get the permits they need to refurbish the historical holdings.

An army barracks in the centre of Trieste and a residence in the Catholic pilgrimage centre of Loreto are also on the virtual auction block for bids due in by May 6.

"Investors can bid for our properties from everywhere, from New York or Dubai," Stefano Scalera of Demanio, the public agency that manages Italian state properties, said on Monday.

"Through the internet they can download documents and contracts, we have translated them all into English," he said.

The Venetian lagoon island is Poveglia, just off the western shore of the Lido island. It has been unpopulated since a hospital there was closed decades ago. The 15th century castle is in Gradisca d'Isonzo, near the border with Slovenia.

Forty other ordinary assets are on offer with the five prestigious properties on the Demanio website (https://venditaimmobili.agenziademanio.it/AsteDemanio_FE/index.php).

Italy, which owns more than 500,000 commercial and residential properties, has struggled in the past to sell state-owned assets because complex bidding rules and snail-paced procedures for permits to restructure old buildings have kept investors at bay.

"This time is different. The main administrative hurdles for these assets have been cleared ahead of the sale," Scalera said, without estimating revenues he expected to come from the sale.

Demanio has raised 1.8 billion euros since 2001 through selling state-owned properties. Italy has pencilled in a gain of 500 million euros ($694.4 million) by the end of this year from the disposal of real estate assets.