Michael Edwards has quit his role as chief executive of football with Liverpool owners Fenway Sports Group, the company announced on Friday.
Edwards, Liverpool's former sporting director, was appointed to his new job in March 2024, shortly before the departure of manager Jurgen Klopp, with a remit to head up a multi-club operation for FSG.
However, the American owners shelved those plans late last year.
Edwards said in a statement issued by FSG that he was leaving Liverpool in a "strong position".
"When I returned, I was excited not only by the opportunity to help guide Liverpool through an important period of transition, but also by the chance to help shape FSG's wider football ambitions," he said.
"While that broader project ultimately evolved differently to how we had originally envisaged, I am proud of the work our team undertook in presenting ownership with a broad range of thoughtful and well-developed options for the future."
FSG said Edwards' departure marked the "culmination of a planned transition following the completion of key strategic priorities".
FSG president Mike Gordon praised Edwards' "extraordinary contribution" to Liverpool and FSG.
"His return to the organisation saw Liverpool successfully navigate a significant period of transition before securing the club's historic 20th English league title, an achievement to which Michael made an important contribution," he said.
In his previous spell at Liverpool, Edwards had notable success in the transfer market, bringing in a string of star players including Mohamed Salah and Virgil van Dijk.
The club ended a 30-year wait for the English league title in 2020 under Klopp and won the Premier League again under Dutchman Arne Slot in the 2024/25 campaign.
But they lost their way badly after spending heavily following that title triumph, slipping to a fifth-placed finish last season.
That resulted in the sacking of Slot and his replacement by Bournemouth boss Andoni Iraola.
There is also speculation that Liverpool's sporting director Richard Hughes could be set for a move to Saudi Arabia.