Mr. Plepler did not explain the reason for his departure, but said in an email addressed to all of the company's staff: "This is the right time for me to do it".
This news comes just days after a court of appeal ruled in favor of the acquisition by WarnerMedia, the parent company of HBO, formerly known as Time Warner. (CNN is also a unit of WarnerMedia.)
"It is the great joy of my professional life to share this adventure with you in all these years. And the great honor of my professional life being your CEO, "writes Plepler in his memo to the staff. "I do not have the words to express my gratitude for the support and talent that made our shared success possible, but let's just say that, my love for this place and for you all, is deeply rooted in me and lasts a lifetime. "
In his memo, Plepler said he informed John Stankey, chief executive of WarnerMedia, that he "would work closely with him to ensure a seamless and organic transition."
To achieve dominance, AT & T and HBO will have to find a delicate balance. HBO is known for its high quality programming and produces much less content than Netflix.
Nevertheless, Netflix has conquered the critics and position itself as a formidable competitor to HBO. The streaming service earned 112 Emmy nominations last year, ending the long-standing reign of the king of premium television in this region. They tied for the most wins.
"We need several hours a day," Stankey said, according to the Times. "It's not hours per week or hours per month, we need hours a day, you're competing with devices that catch their attention every 15 minutes."
Stephenson said that he was not talking about "Netflix-type investments" and also qualified the competitor's "Walmart" video streaming on demand. On the other hand, he called HBO the "Tiffany".
Warner Media has subsequently announced plans for its own streaming TV service that will be sold directly to consumers. Stankey said the service "would start with HBO and programming that defines the genre and which viewers want." There will be three versions of this streaming platform. Its launch is scheduled for this year, although the company has not yet specified when.