AT&T has agreed to sell its ad marketplace, Xandr, to Microsoft as the ad industry tries to adapt to a post-cookie world.

The ad industry has been working to cope with changes to online advertising, including initiatives to replace the web browser cookies that have formed the backbone of the industry for years. AT&T says Xandr compliments Microsoft’s current efforts in the context of the open web.

“Microsoft’s shared vision of empowering a free and open web and championing an open industry alternative via a global advertising marketplace makes it a great fit for Xandr. We look forward to using our innovative platform to help accelerate Microsoft’s digital advertising and retail media capabilities,” said Xandr’s EVP and GM Mike Welch.

“With Xandr’s talent and technology, Microsoft can accelerate the delivery of its digital advertising and retail media solutions, shaping tomorrow’s digital ad marketplace into one that respects consumer privacy preferences, understands publishers’ relationships with consumers and helps advertisers meet their goals,“ said Mikhail Parakhin, President of Web Experiences at Microsoft.

The deal is subject to regulatory review. Neither company disclosed the financial terms of the deal.