(Adds quote from KKR, Blue Harbour Group)
July 24 (Reuters) - Private equity firm KKR & Co has agreed to buy WebMD Health Corp for about $2.8 billion, bringing a slew of popular online health information websites under one umbrella, and separately said it would buy a major stake in Nature's Bounty Company.
The WebMD deal is five months after the New York-based company said it would explore strategic options amid a slowdown in advertising paid for by pharmaceutical companies.
KKR's Herald Chen said in an interview that Internet Brands will take what it has learned selling marketing services subscriptions, which bring in more recurring revenue than advertising, and apply a similar strategy to WebMD.
"We think there are many ways to expand on WebMD's current platforms and also build new solutions," Chen said.
KKR will pay $66.50 per share, a premium of 20.5 percent to WebMD's Friday closing and 33 percent higher than the stock's trading price at the start of the year.
WebMD's shares closed up 20 percent at $66.10, just shy of the offer price.
Analysts said the deal price was higher than expected, adding that WebMD was a good fit for Internet Brands' portfolio.
"We are pleasantly surprised by the premium valuation, given the flat growth expected," Cowen & Co analyst Charles Rhyee wrote in a note.
Blue Harbour Group, an activist hedge fund that owns 9 percent of WebMD shares, said in a statement that it supported the deal and that the company had conducted a "thorough strategic process."
Founded in 1996, WebMD has grown into one of the most popular health websites for consumers and medical professionals, attracting more than 70 million monthly unique visitors in 2016, according to analytics company comScore Inc.
WebMD's Medscape, a medical news and education website, accounted for about 60 percent of the company's advertising revenue in 2016.
Internet Brands, which launched as CarsDirect.com in 1998, licenses and delivers its content and internet technology products and services to small and medium-sized businesses.
It was acquired by KKR in 2014 for $1.1 billion from two other private equity firms, Hellman & Friedman LLC and JMI Equity.
Reuters reported on Sunday that KKR was nearing a deal to buy the online health information provider.
Separately, KKR said it would buy a majority stake of the Nature's Bounty Company from the Carlyle Group.
Carlyle will retain a significant stake in the company. Financial terms of that deal were not disclosed.
WebMD also announced preliminary second-quarter sales that topped the average analyst estimate.
J.P. Morgan Securities LLC was WebMD's financial adviser, while Shearman & Sterling LLP was its legal adviser. Simpson Thacher & Bartlett LLP was Internet Brands' legal adviser. (Reporting by Ankur Banerjee in Bengaluru and Liana B. Baker in New York; Editing by Saumyadeb Chakrabarty, Bernard Orr)