The Italian carrier Alitalia will join an alliance of Air France-KLM and Delta Air Lines that shares revenue and costs on trans-Atlantic routes, giving the group access to Europe’s third-biggest market, Reuters reported.

In a statement on Monday, the airlines said the addition of Alitalia to the alliance meant that the venture represented about 26 percent of the total trans-Atlantic capacity, with annual revenue of more than $10 billion.

Air France-KLM holds a 25 percent stake in Alitalia. The Italian carrier sought bankruptcy protection in 2008 after years of struggling with strikes and inefficiencies and was restarted as a private airline by Italian investors last year.

It had a difficult rebirth, struggling with low passenger numbers and flight delays that prompted a barrage of complaints. But the airline’s performance in the first half of the year showed strong improvement from a year earlier, with revenue rising 10 percent, the airline’s chief executive, Rocco Sabelli, told a news conference.

He played down speculation that the airline might be forced to raise capital again in the coming months, saying there were no plans to do so. He also denied speculation that Air France-KLM planned to buy the Italian airline.