Qatar Airways agreed to buy a 49 percent stake in Meridiana Fly SpA as a spat with labor leaders waned at Italy’s second-biggest airline, marking the Persian Gulf carrier’s third investment abroad to expand its global reach. Qatar Air signed an agreement with Alisarda SpA, a holding company of the Aga Khan that owns Meridiana, for a transaction expected to be completed in early October, subject to “certain conditions,” the carrier said Thursday in a statement, without specifying the value or other terms. The accord “sets the path to progress” for a “strong resolution” that will benefit employees and passengers of Meridiana, Qatar Airways Chief Executive Officer Akbar Al Baker said in the statement following the contract signing at the Farnborough Air Show outside London. The plan, outlined early this year, was in doubt in the past month as unions at Meridiana objected to job-cut plans. Even with a labor settlement reached at the end of June, Al Baker said as recently as Tuesday that he was willing to walk away from an investment because he wouldn’t accept “blackmail by staff.” The stake purchase was the second announced by Qatar Airways at Farnborough. The carrier plans to buy as much as 10 percent of Santiago, Chile-based LatAm Airlines Group SA for $613 million. It’s also considering increasing its 15 percent holding in IAG SA, the parent company of British Airways and Spanish carrier Iberia. The Meridiana investment will put Qatar Airways up against Abu Dhabi-based Etihad Airways, which has bought 49 percent of the Italy’s largest carrier, Alitalia.