* Alitalia threatens to move hub, cites poor infrastructure
* Airport operator says committed to investment
* Etihad took 49 percent stake of Alitalia, promising turnaround
By Philip Pullella
ROME, July 30 (Reuters) - First, a fire in May reduced operations at Fiumicino airport for more than two months. On Wednesday, a forest fire caused cancellations and delays, and on Thursday a black-out left much of it without power for an hour.
Italy's busiest airport has not been very lucky of late.
Now its biggest tenant, national carrier Alitalia, has threatened to move its hub elsewhere unless airport operator ADR does more to improve infrastructure and services.
Alitalia CEO Silvano Cassano said the airline, which operates about 50 percent of flights at Fiumicino, had avoided polemics while the airport was recovering from the May fire in a terminal but made clear it was now taking the gloves off.
He told ADR, a unit of motorways operator Atlantia, that the airline would be seeking at least 80 million euros in damages blaming the "overall fragility of the airport's infrastructure" for the slow recovery from the May fire.
"Fiumicino airport still does not have an adequate infrastructure to be hub for a company with our ambitions," Cassano said in a statement on Wednesday.
Last year, Abu Dhabi-based Etihad Airways bought nearly half of Alitalia and promised to invest some 560 million euros into the loss-making airline in a turnaround that involved heavy job losses.
Cassano told ADR that if it continued to "concentrate on low-cost airlines and mediocre services (at Fiumicino) Alitalia will be forced to move its growth elsewhere".
He did not say where the airline could move its hub but the most likely candidate is Milan's Malpensa, the largest of the two airports in Italy's financial capital.
ADR said it would not comment on "the foundation" of the amount of money Alitalia wanted in damages but said it was determined to move ahead with an 11-billion-euro investment plan for the airport.
Civilian air authority Enac said it had summoned Alitalia and ADR executives to a meeting on Aug. 6 over how they handled the effects of Wednesday's forest fire.
Interior Minister Angelino Alfano said the May fire was not caused by arson. Officials suspect the forest fire was started intentionally in three separate parts of a nature reserve.
Passengers interviewed on Italian television on Thursday said it was still chaotic a day after the forest fire, with one woman saying she waited six hours on a plane. (Editing by Janet Lawrence)