AT&T to merge media and entertainment division with Discovery Inc., forming streaming behemoth that includes HBO and CNN Less than three years after spending $85 billion in a battle to acquire Time Warner Inc. and fighting off a government challenge, AT&T announced Monday it would combine its WarnerMedia assets with those of Discovery Inc. If approved by federal regulators, the merger would combine Discovery’s reality TV empire with AT&T’s well-known brands, including HBO, CNN, Cartoon Network and the Warner Bros. Studio, in hopes of better competing with Netflix and Walt Disney Co.