Carmine Di Sibio, the global chair and CEO of EY who led an ultimately failed charge to split apart the $50 billion firm, told partners on Tuesday that he will retire next summer.

Di Sibio received a two-year extension to his tenure last fall and had been expected to remain in the firm’s top leadership role through June 2025. He reached the firm’s mandatory retirement age in March.

“I am proud of the bold vision we set out in Project Everest,” Di Sibio said in a statement, referring to the firm’s internal name for the now defunct break-up deal. “The courage that we displayed set the entire sector on a new course that will only become apparent in the years to come. We challenged the status quo, we asked tough questions, and we were bold in our ambitions.”

Di Sibio’s pending retirement sets up a selection process for a new chairman and CEO to steer the Big Four accounting firm as it recovers from the botched restructuring. The planned overhaul fell apart amid leadership infighting and a transaction that didn’t stretch far enough to solidify partner support.

Di Sibio, who described his time as chairman as both “humbling and challenging,” championed the carve-out strategy that would have freed the firm’s lucrative consulting business from strict conflict of interest rules tied to its mainstay audit practice. The restructuring would have allowed the consulting business to offer its services to more clients, bolstering profits for its leadership ranks.

He stepped in to serve a four-year term as chairman and CEO in 2019, succeeding Mark Weinberger, to whom he had reported as managing partner for client services. Earlier in his career, Di Sibio was a US audit partner and was later the Americas regional managing partner for financial services, among other roles.

Steering the firm through the Covid-19 pandemic, Di Sibio led EY to a nearly two-decade high in revenue in its last fiscal year.

Under his leadership, EY invested in its environmental commitments, achieving carbon neutrality in 2020 and naming a global sustainability officer. And he worked with other Big Four leaders and the World Economic Forum to craft a set of disclosures meant to whittle down the list of environmental, social and governance metrics that companies share with stakeholders.