This story has been updated.

NEW YORK (AdAge.com) -- WPP will roll up multiple digital agencies into a new agency, Possible Worldwide, with headquarters in New York and 17 other offices across the world, the company announced in a statement. Clients at launch will include AT&T, Dell, General Mills, Microsoft, Nokia and Procter & Gamble.

The unit, which would swallow up Schematic , Bridge Worldwide and others, would add WPP's first digital-only agency network to its stable of iconic brands such as Ogilvy & Mather, JWT and Young & Rubicam.

WPP, the largest holding company by worldwide revenue, has four digital agencies under WPP Digital that are not affiliated with any other agency networks: Schematic and Bridge Worldwide are both based in the U.S., with Blue Interactive Marketing in Singapore and Quasar Media in India. Trevor Kaufman, CEO of Schematic , is said to be the new network's CEO, reporting to WPP Digital CEO Mark Read.

Combined, the four agencies had $104 million in U.S. revenue, according to Ad Age DataCenter estimates, with offices in the U.S., India, Singapore, Costa Rica and London. The rollup puts the new agency in the top 20 U.S. digital agencies by revenue, a list topped by WPP-competitor Publicis Groupe. Ogilvy Interactive and Wunderman are the only WPP agencies in DataCenter's top 20 digital agency list.

Publicis' Razorfish and Digitas are the two largest U.S. digital agencies with $317 million and $295 million in 2009 revenue, respectively, according to DataCenter.