Aguero dazzled over an illustrious decade-long spell at City, winning the Premier League title four times, the League Cup on five occasions, and the FA Cup in 2018-19.
The 32-year-old is likely to add to his trophy cabinet before he departs, as City remain in the hunt to win an unprecedented quadruple.
"A huge sense of satisfaction and pride remains in me for having played with Manchester City for a whole 10 seasons - unusual for a professional player this day and age," Aguero wrote in a statement.
"Ten seasons with major achievements, throughout which I was able to become the top historic goalscorer and forging an indestructible bond with all those who love this club - people who will always be in my heart."
Aguero famously delivered City's first Premier League title on the final day of the 2011-12 season with a 94th-minute winner against Queens Park Rangers. The goal bumped crosstown rivals Manchester United out of first place on goal difference.
Commentator Martin Tyler's famous call of Aguero's heroics makes the rounds to this day.
But it is Aguero's longevity as City's go-to striker that sets him apart. The Argentine has scored 257 goals in 384 appearances since joining City from Atletico Madrid in 2011, breaking Eric Brook's 78-year-old record in the process. Among those tallies is a Premier League-record 12 hat-tricks.
Aguero transformed into a complete player upon Pep Guardiola's arrival in 2016, upping his intensity and contributing to the team's build-up play. But several injuries have curtailed his contributions over the past year. Aguero, who also missed time with COVID-19, has started just five matches in all competitions this season.
"Sergio's contribution to Manchester City over the last 10 years cannot be overstated. His legend will be indelibly etched into the memories of everyone who loves the club, and maybe even in those who simply love football," Al Mubarak said.
"This is not yet the moment for farewell words and speeches. There is still much to achieve in the remainder of the time we have with Sergio, and we look forward to his contributions to the challenges which lay ahead."
It's unclear where Aguero will end up next. He previously expressed a desire to return to Argentinian club Independiente, where he started his career, and he's also been linked with Barcelona, Paris Saint-Germain, and Juventus. He'll be available on a free transfer.