WebMD scrapped plans for a possible sale and announced that president and CEO Wayne Gattinella is stepping down after 11 years in that role.

The digital health giant said it had “terminated” talks with “several potential acquirers,” having opened its books for them and, presumably, received disappointing offers. The company issued a grim preliminary outlook for 2012, forecasting revenues down 2%-8% year-on-year.

“WebMD’s fourth quarter sales activity for advertising and sponsorship products was less than anticipated and reflects a challenging business environment,” said a company statement, which added that loss of patent protection on key drugs was “having a greater than previously anticipated impact on marketing expenditures.”

Fourth-quarter sales of advertising and sponsorship products were disappointing, the company said, and the slump is expected to continue through the first half of the year, with spending picking up in the second half as a number of new brands launch.

Also cutting into WebMD’s revenues: more competition for consumer products advertising “from a variety of ad networks and social sites,” the firm said.

“There is significant growth opportunity ahead for WebMD,” said board chair Martin Wygod in a statement, noting that the portal “offers a cost-effective, efficient and highly measurable alternative to traditional detailing to physicians and mass media to consumers.”

CFO and COO Anthony Vuolo is the interim CEO, pending a board search for that post. He will be aided by a management committee consisting of: EVP, consumer services Gregory Mason; EVP, chief technology officer William Pence; EVP, professional services Steven Zatz, MD; and SVP, sales Dorothy Gemmell.

WebMD’s brands include the eponymous consumer portal as well as Medscape, MedicineNet, emedicineHealth, RxList, theheart.org and Medscape Education.