By Agnieszka Flak

MILAN, April 25 (Reuters) - Alitalia said on Tuesday it would start insolvency proceedings after workers rejected its latest rescue plan, making it impossible for the loss-making Italian airline to secure funds to keep its aircraft in the air.

Workers on Monday rejected a plan to cut jobs and salaries, betting the government will be asked to call in an administrator to draft an alternative rescue plan.

The flag carrier, 49 percent-owned by Etihad Airways, has made an annual profit only a few times in its 70-year history. The company, with around 12,500 employees, is losing at least 500,000 euros ($543,000) a day and is set to run out of cash in coming weeks, sources familiar with the matter have said.

Alitalia was seeking worker backing to unlock fresh funds from shareholders and launch an ambitious restructuring plan, centred around a revamp of its business for short and medium-haul flights and additional long-haul routes.

"An approval ... would have unblocked a 2 billion-euro capital increase, including 900 million euros of fresh funds, that would have been used to relaunch the company," Alitalia said, adding it regretted the vote which had made a recapitalisation impossible.

The company has called a shareholder meeting for Thursday to decide on the next steps, adding its flight operations were unchanged for now.

The most likely outcome is that the company will ask the government to appoint a commissioner to assess whether the carrier can be overhauled or should be wound up.

The commissioner would then prepare industrial and financial plans for a rapid revamp of Alitalia, either as a standalone company or through a partial or total sale, or else put it on course for liquidation.

Workers had repeatedly said they were unwilling to accept any further sacrifices when Alitalia's labour costs were already among the lowest in Europe for a so-called legacy airline. They were also sceptical over its plans to return to profit by 2019, given a string of failed restructurings in the past.

Alitalia has been bailed out by Italian governments and private investors repeatedly over the years, rarely requiring strong industrial strategies in return.

Even though Rome has said it will not re-nationalise the carrier this time, some workers still hope the government will not let the company collapse.

(Reporting by Agnieszka Flak; Editing by Mark Potter) ((agnieszka.flak@thomsonreuters.com; +39 02 6612 9450; Reuters Messaging: agnieszka.flak.thomsonreuters.com@reuters.net))

Keywords: ALITALIA RESTRUCTURING/