The Online Powerhouses Get Comfortable Orbiting Madison Ave

Next week, when 60,000 people in marketing and communications are expected to descend on New York for Advertising Week, some of the world’s largest tech companies will be taking center stage.

Once dismissed as ancillary players at the eight-year-old gathering, online heavyweights like Google, Yahoo and Facebook will play a more prominent role, with panel discussions on mobile connectivity, online privacy and social networking all grabbing top billing among the tangle of 200 events. But amid the clamor of seminars and after-hours parties, some of those same companies will also be hosting prominent events on their home turf, made possible by a recent flurry of office expansions. While Silicon Valley’s most formidable Internet behemoths have leased office space in New York since the 1990s, their rapidly shifting partnership with Madison Avenue has driven the move from back-office cubicles to elaborately designed corporate suites intended to impress advertisers. While Palo Alto, Calif., remains a hub for computer engineers, New York has surged as a location for the virtual world’s unsung marketing and sales divisions, with Facebook, Google, Yahoo and Apple all expanding in the city since 2010.