When Motorola Mobility lined up a Silicon Valley candidate a few months ago for a VP-level role, the phone maker was hopeful he'd accept. After all, the company offered the chance to develop products at a subsidiary of Google Inc.

The engineer declined. His reason: the prospect of relocating to Libertyville, Ill., about 35 miles from downtown Chicago, said Scott Sullivan, Motorola's head of human resources.

Mr. Sullivan expects recruiting to get a lot easier next February when the company moves into a new space in the storied Merchandise Mart building in downtown Chicago.

Motorola will join United Continental Holdings Inc., Hillshire Brands Co. —the successor to Sara Lee Corp.— and other corporate giants abandoning vast suburban campuses for urban offices nearer to the young, educated and hyper-connected workers who will lead their businesses into the digital age. Archer Daniels Midland Co. recently said it would move its headquarters from Decatur, Ill., and in the Bay Area, startups like Pinterest Inc. are departing Silicon Valley for San Francisco.

After decades of big businesses leaving the city for the suburbs, U.S. firms have begun a new era of corporate urbanism. Nearly 200 Fortune 500 companies are currently headquartered in the top 50 cities. Many others are staying put in the suburbs but opening high-profile satellite offices in nearby cities, sometimes aided by tax breaks and a recession that tempered downtown rents. And upstart companies are following suit, according to urban planners. The bottom line: companies are under pressure to establish an urban presence that projects an image of dynamism and innovation.