UPDATE 1-Shares in Italy's Carige fail to start trading after 2-1/2 year halt

(Recasts with shares failing to start trading)

MILAN, July 27 (Reuters) - Shares in Banca Carige failed to open on Tuesday on the first day of trading after a two-and-a-half year suspension triggered by the European Central Bank’s decision to place the Italian regional lender under special administration.

“The spread between the bid and offer price is too wide so the shares fail to open,” a Milan-based trader said, adding there was a lot of uncertainty about the stock.

To keep Carige in business, Italy’s depositor protection fund (FITD) pumped 600 million euros ($709 million) into the loss-making bank at the end of 2019.

Financed through contributions from Italian banks, the FITD acquired in the bailout an 80% stake in Carige that it currently values at around 100 million euros - or 0.17 euros per share.

Shares in Carige last traded at around 1.50 euros at the end of December 2018 before being suspended and before the capital increase subscribed by the FITD a year later.

However, Italy’s bourse said on Monday there would be no reference opening price for Carige shares. It added that trading orders without a price limit have been banned.

After rival Cassa Centrale Banca walked away from a possible acquisition, Carige last week said there was no certainty it could strike a merger that it sees as key for its eventual relaunch.

In an investor prospectus published ahead of the trading resumption, Carige also said it needed a further 400 million euros ($473 million) in capital by the third quarter of 2022.

In the document it warned of possible wide price swings once trading resumed.

With a free float equivalent to just 11.7% of the bank’s capital, low liquidity could also affect share price movements, it said.

$1 = 0.8467 euros Reporting by Andrea Mandalà; editing by Valentina Za and Kirsten Donovan