AT&T has just handed the keys to WarnerMedia’s most high-profile business initiative to Bob Greenblatt, the seasoned TV executive whose resume includes helping to build the Fox network in its infancy, bringing Showtime to prominence with original series and revitalizing NBC during the past eight years.

As of Monday, Greenblatt is driving WarnerMedia’s bid to launch a global streaming platform in his new role as chairman of WarnerMedia Entertainment and Direct to Consumer. He’ll have to maintain HBO’s gilded brand, steer TNT and TBS through the choppy waters of ad-supported cable, and he’ll have to find the way to make disparate WarnerMedia units work together more closely than they ever did in the Time Warner days.

Greenblatt took time out from his first day as a WarnerMedia employee — as he battled a head cold on a snowy morning in New York City — to speak with Variety about how his new job came together and how he sees WarnerMedia competing in TV’s real-life Game of Thrones.

When did you start talking to WarnerMedia about this job?

It was very recently. I’ve been spending the last few months talking to people and there were even some producing projects I got involved in. I wasn’t sure exactly what the next step would be for me. John (Stankey) reached out to me after the first of the year and said ‘I think there’s a place for you in this company as I’m thinking about reorganizing it. We had several conversations. The more I learned about it the more excited I got and the more I thought it made a lot of sense. I don’t know of a better opportunity or challenge than this. The HBO of it all a personal thrill having produced a show here (“Six Feet Under”) that was one of the joys of my life.

What is your mandate from Stankey and from AT&T?

They are looking at the unique set of assets that they have and want to bring them together in a streaming service. They want to be aggressive in this new world order. He wants me to pull it all together. There are enormous challenges and opportunities. Every seven or eight years I like to take on anew challenge, and this is the one that came my way.

What can you tell us about WarnerMedia’s streaming service plans? People in the industry don’t yet have a sense of what it will be.

It’s really early days. I don’t have a great and comprehensive answer for you yet. I would just say that the goal here is to put all of these assets that this company has — from the movie studio to HBO and Turner and the vast library — and build a platform that is robust and a great value to the consumer. There’ s a million questions to answer about where we’re already selling content now, should we continue to do that, how exclusive should we be? There are a million questions that have to be answered. We all need to roll up our sleeves as one company to pull that together.

Will the streaming service have original content that is distinct from what is produced for HBO and the Turner nets?

HBO is central to the whole thing. How it will be tiered and all of that is still in the working stages. HBO will be part of it, Turner programming will be part of it and original programming will be part of it. The volume for each of those and how much we’re going to spend — it’s too early to get too specific on it. We want to bulk up with as much great stuff as we can.

What do you think of HBO as it stands today?

I think it’s one of the greatest brands on the planet. It’s the greatest TV brand that’s ever been. It set the standard for TV and continues to have that extraordinary standard. I love so many of the shows personally and the budgets were just increased significantly before I got here — some are up by 50% which is enormous.

Are you worried about HBO’s competitive position after “Game of Thrones” end later this year?

Every network gets to a place where some of its biggest shows are ending, like “Game of Thrones” and “Veep” and then you have to look at the next phase. (HBO programming chief) Casey (Bloys) and the team have been out there working with the some of the best people in our business, making commitments and picking up shows. My goal is to do nothing but protect that and nurture that brand. I’m nothing if not a premium cable guy — between Showtime and “Six Feet Under.” I want this brand to grow and prosper. It’s one of the greatest brands ever in our business. My hat’s off to (exiting HBO CEO) Richard Plepler, a pioneer.

How will you divide your time among your various responsibilities to manage HBO, TNT, TBS, TruTV, and the DTC platform launch?

I’m really comfortable delegating as I did with the great team I had at NBC. I want to empower Casey and Kevin to continue doing what they’re doing. I’m here on a high level to pull together and coordinate how these companies are going to work together for the purposes of the streaming service. We want to keep the HBO and Turner brands distinct from one other. I’m a big proponent of getting people together and having everybody strategizing and feeling like they’re part of the bigger while running their own areas. It’s one of the biggest challenges I have ahead. We have to keep these brands really strong and independent and we have to bring them all together under this new digital umbrella. I think this company the way it’s grown up over the years was as a collection of separate companies. It’s time to bring it together at a higher level. The devil’s in the details. All these different assets are here — now it’s time for the senior team to really pull them together.

What do you see as the future for TNT and TBS? There’s been talk of cutting back on expenditures on originals in order to funnel more resources to HBO?

At this time there is no intention to bring those networks down or in any way reduce the footprint. What we’re trying to do investment-wise is be really efficient at how the networks are run so that we can take whatever savings we have and put it back into programming, both at HBO and Turner. I don’t honestly know yet what the Turner networks have. I haven’t done a big deep dive into them creatively yet. I certainly want to keep them really healthy with original programming. We have to see as we get into it what that really means. But it’s not like we’re going to strip-mine Turner to beef up HBO.

Are you expecting significant layoffs with the consolidation of the management of HBO, TNT, and TBS?

Over the next couple of years we will really figure out how these groups work together to make it efficient as we can. I don’t think you’re going to see on X day hundreds or thousands of layoffs. I think administratively we’ll try to pull things together where we can, we’ll try to do that in a very smart way. Nobody has said to me ‘Where are we going to get thousands of layoffs.’ I don’t think there are big massive layoffs coming.

Where do you see opportunity for WarnerMedia in the streaming arena, given that the field is becoming so crowded?

We all really do understand the world we are living in. We know there are a couple of big direct to consumer platforms already up and running. We know Disney is hard at work. At the same time everybody over here believes that given the combined assets of this company we have a really great chance of being in that game in a signficant way. I think each one of these (competing) platforms will be very distinct from the other. Will we be as voluminous as Netflix? No. Do we have the plethora of name-brands as Disney? No. What we do have are brands that are really significant starting with HBO.

AT&T is the world’s largest telecommunications company with direct relationships with millions of consumers already. If we can harness the knowledge this company has and the data and the relationships they have to put products in the hands of consumers — that gives us real scale and potency to launch something.

Did you get a specific commitment going in about the kind of resources you’ll have to program your networks?

I am very bullish about this. I wouldn’t be here if I wasn’t. I say that with all honesty and knowing that this is going to be a real challenge to penetrate the (marketplace) that already exists. We’re not the first or second entrant. But everybody is excited about it. I think this the future of the way people want to consume their content. We have no illusions that it’s going to be easy. We certainly have to continue to invest in this great foundation of assets and (harness) the power of these companies together.

Are you still on track to launch the streaming platform in beta form by year’s end?

That’s what we hope to do. The longer you wait, the harder it will be.