WebMDJuly 24 (Reuters) - Online health publisher WebMD Health Corp said on Monday it agreed to be bought by private equity firm KKR & Co in a deal valued at about $2.8 billion. The deal brings together WebMD's websites, such as WebMD.com, Medscape.com and MedicineNet.com, and those owned by KKR unit Internet Brands Inc, including DentalPlans.com and AllAboutCounseling.com. KKR will pay $66.50 per share, a premium of 20.5 percent to WebMD's Friday closing price.