WebMD shares Tuesday tanked nearly a third after the company announced it is no longer looking to sell the company and projected falling revenue for this year in its preliminary outlook.

Shares of WebMD were down 30.68 percent to $25.46 in mid-morning trading.

The New York-based health information company announced late last year that it was looking to sell the company, and it said Tuesday that it met with several potential acquirers before deciding to end talks.

The company also announced that Chief Executive Wayne Gattinella has resigned. Anthony Vuolo, who currently serves as chief financial officer and chief operating officer, will take over the company on an interim basis while a permanent CEO is sought.

Vuolo will continue serving as chief operating officer, while other senior executives will take on the role of chief operating officer.

WebMD's said in its 2012 preliminary outlook that revenue may be as much as 2 percent to 8 percent lower than in 2011. The company said it expects to lose revenue from pharmaceutical companies as many of them lose patent exclusivity.

Furthermore, the company said it will face increasing competition in its consumer products market from a host of ad networks and social media outlets.

WebMD anticipates its expenses will rise in 2012 by as much as 5 percent to 8 percent as the firm looks to make investments in long-term growth in areas such as personalization, mobile, social, international, new content areas and new advertiser products and services.

While we face near-term challenges, I am confident that there is a significant growth opportunity ahead for WebMD, Martin Wygod, Chairman of WebMD said in a statement. I believe that the pressures facing the pharmaceutical industry will ultimately prove to be the strong catalyst for a meaningful shift by them to digital marketing solutions.