Montgomery is handing over the reins of the U.S. production group to David George, his former Leftfield colleague who has been President of ITV America since January 2017. Montgomery will set up production group Wheelhouse Entertainment and has secured a production partnership with ITV America, where he will remain as a strategic advisor for six months. Joining him at the new firm will be his key lieutenant Ed Simpson, who has served as EVP, business development and international at ITV America.

Under Montgomery’s watch, ITV America became the largest non-scripted production group in the U.S. with labels including his own Leftfield Pictures, ITV Entertainment, run by former Turner and Mark Burnett executive David Eilenberg, Marriage Boot Camp producer Thinkfactory Media, Cake Boss indie High Noon Entertainment, Loud TV, Outpost Entertainment and Sirens Media. It also has a number of talent-fronted partnerships with the likes of Michael Strahan, John Cena and Bethenny Frankel.

Some of the biggest wins under Montgomery’s watch including Fox music competition series The Four: Battle for Stardomand Queer Eye for Netflix, and the firm also produces the likes of Hell’s Kitchen, HGTV’s Fixer Upper, A&E’s The First 48 and Duck Dynasty, Bravo’s The Real Housewives of New Jersey, History’s Pawn Stars, Alone and Forged in Fire.

Last year, Montgomery and ITV America were dragged into a legal row with Duck Dynasty producers Gurney Productions after ITV America accused Scott and Deirdre Gurney accounting fraud and other transgressions. In December, a Los Angeles Superior Court restored ITV’s rights to bar the pair from running the company but upheld the fact that they still have the legal right to serve as Gurney board members.

Montgomery said that he was looking forward to starting his next chapter and that leaving was the “most difficult decision of my career”. “Now, as I look to build and grow a new company, I am thrilled to continue to partner with ITV America, the best in the business and whose great fortune it is now to be led by my long-time partner David George. He took Leftfield Pictures and made it better, he took Leftfield Entertainment and grew it, and I expect nothing less at ITV America.

“The trust and support ITV has shown me over the last four years is unprecedented. I couldn’t be more thankful and proud of our accomplishments, and am happy to be leaving the company in great hands, and with an incredible slate of cable, network and OTT shows heading into the new year,” he added.

Julian Bellamy, managing director, ITV Studios, added that he fully understood Brent’s decision. “He’s an entrepreneur at heart and this move takes him back to what he loves doing most. I would like to thank Brent for being a fantastic leader of ITV America and I’m delighted he will be partnering with us in his new venture. Brent hands over a business in great shape with an exceptionally strong team behind it. It’s a testament to his leadership that we are able to appoint a new CEO from within the group.”

Bellamy added that he was delighted that George was stepping up as CEO and called him a “brilliant creative and talented business leader”.

Updated with David George internal memo:

Today is an incredible day for me as I am thrilled to be given the opportunity to steer ITV America at such an interesting time in the evolving media business.

A long time ago, in a galaxy far far away, Brent Montgomery came to meet me at MTV and pitched me a concept. I hadn’t really heard of Leftfield Pictures, but I knew there was a new show Pawn Stars that was making waves and this was the company that did it.  It was the beginning of something incredible, and Brent saw something in me that no one else did.  He gave me an incredible opportunity to join him.  It literally was the best decision of my professional life.

Thousands of hours of programming later, that opportunity remains as strong as ever.  If you look at us as a group we are doing so many incredible things. We are leading the charge into new platforms with series coming on Facebook and Netflix. We have the biggest and baddest music competition on Fox in The Four. We are primed to evolve and become even greater in the coming years. That is Brent’s legacy.

It is also a bit bittersweet for me to be saying goodbye to Ed Simpson in his current role. I can’t say enough about how much he has meant to building this company and helping us form the many meaningful partnerships we have across the board. Ed has done so many wonderful things for us and this is his legacy as well.

The best part of all of this is they both remain in the family, moving on to the next chapter working with ITV in a fresh and new way. You may ask yourself why all of this makes sense right now. The answer is quite simple. This market is all about evolving and adapting. I am so proud of what they are going to do because it’s a new way to attack the market. That has always been the name of the game for us at Leftfield and now ITV.

As for our future at ITV America, there are many amazing things to reveal in the next few months. We are going to evolve and adapt as well. Our presence in the market is stronger than ever. That means opportunity for us all. But we cannot rest on what we’ve done. We must continue to push ourselves to think outside the box and be as bold creatively as we can be. That is what excites me the most about taking this role.

Please join me in thanking Brent and Ed for all they have done and will continue to do for this company. And please come ride with me as we head towards the future with incredible hope and excitement for what is to come. ITV America is just beginning its story. We have work to do.