Having informed the board of his desire to leave the position, Simms will remain with the organisation for several months to "facilitate an orderly handover."
The board is now seeking Simms' replacement, targeting someone who can "build upon the transformation of XLMedia" in recent years.
By comparison, Jesper Søgaard, CEO of Better Collective, leads the huge affiliate having co-founded it in 2004, while Michael Daly leads Catena Media, another significant player within the iGaming market, having taken over as CEO on 1 March 2021.
Simms became Group CEO of XLMedia in October 2019, overseeing growth and considerable M&A during that time.
However, XLMedia's financial reports during the period did offer up some stumbling blocks, with certain verticals ending up far from smooth sailing for the affiliate.
Julie Markey, Interim-Chair at XLMedia, said: "I would like to thank Stuart for his contribution to XLMedia through a very challenging period in our history.
"He departs having expanded our sports footprint in North America, a key strategic focus. I, on behalf of the Board, wish him all the very best for the future."
And Simms added: "During my time at XLMedia, and with the support of my team, we have been able to deliver substantive, tangible change; de-risking the core business whilst moving the company's operational focus towards the growing North American sports market – creating a strong asset base capable of delivering shareholder value for many years to come."
