Delta has extended its policy of blocking its middle seats until May.
The US carrier said its policy to limit capacity on all flights by implementing the measure would continue until April 30, having been first introduced in April last year.
It said the decision would “ensure customers can confidently plan and book their spring travel”.
Bill Lentsch, chief customer experience officer, said: “We want our customers to have complete confidence when travelling with Delta, and they continue to tell us that more space provides more peace of mind.
“We’ll continue to reassess seat blocking in relation to case transmission and vaccination rates, while bringing back products and services in ways that instil trust in the health and safety of everyone on board.”
Delta said it was also introducing additional measure to assist and reassure customers, including issuing clear guidance on testing requirements and other restrictions in destinations, streamlining test scheduling and automated document verification and deploying teams of “clean ambassadors” at more than 55 airports.