Two years after Delta Air Lines tapped Omnicom's PHD as its primary media agency in the U.S., the brand has consolidated all of its media work with the agency, according to people with knowledge of the matter.

Following the last review, Publicis Groupe's Digitas — which had been the incumbent on the account — continued to handle some digital marketing tasks that now move to PHD. Digitas still works with Delta on customer relationship management.

Delta did not respond to requests for comment on the change. The agencies referred comment to Delta.

During the brand's first-quarter 2018 earnings call on April 12, when asked about passenger ticket revenue, Delta CEO Ed Bastian said the company was thinking about diversified revenue streams, and said "there's no question, our non-ticket-based revenues … And it's been for some time now, it's been growing at a much faster clip than the ticket revenues. And as we bring segmentation and more customized marketing to bear, you'll see those trends continue."

Delta Airlines spent an estimated $34.8 million in measured media in the U.S. in 2017, according to Kantar Media.