Omnicom Media Group and Twitter announced a mobile-advertising deal yesterday that is said to be valued at $230 million over the next two years. The agreement will integrate Accuen, Omnicom’s ad buying unit, with MoPub, the ad exchange that Twitter acquired in September for $350 million. The deal will lock in advertising rates and access to inventory for Omnicom agencies, while also providing a first look at new ad units and related opportunities being developed by Twitter.

“This is the first holding company agreement we’ve done on the mobile ad exchange side,” said Adam Bain, Twitter’s president of global revenue. “It’s great for us because we’ll now have high-quality advertisers coming through the exchange.”

“Twitter has struck similar partnerships with other holding companies over the past two years,” reports The Wall Street Journal. “Last April it signed one with Publicis-owned Starcom MediaVest Group worth a reported $200 million over two years, for example. According to Mr. Bain, each of these deals is different, depending on what the agency wants from the social network.”

“This one is unique because it focusses on the tech part of how ads will be delivered,” explains Bain.

Currently, ads that are purchased programmatically from Twitter appear only on third-party sites in the MoPub network, but Twitter says it plans to enable marketers to buy ads directly. It is possible that the new deal with Omnicom could head in that direction.

The article notes that Facebook signed a multi-year deal with Publicis last week that is also worth “hundreds of millions.”