Developer Larry Silverstein’s attempt to derail a $1.2 billion settlement of property damage claims filed against airlines and security companies accused of negligence after the 9/11 terrorist attacks was rejected Friday by the U.S. Court of Appeals for the Second Circuit.

Mr. Silverstein, the World Trade Center leaseholder, had claimed that the settlement reached last year between plaintiffs and American Airlines, United Airlines and other defendants was collusive and would reduce the money his properties, which refused to settle, could recover.