The actress, who plays factory boss Carla Connor, will leave at the end of the year.
An ITV spokesperson said: "Alison King has indicated to producers that she would like to take a sabbatical from the show for creative reasons at some point in 2016.
"She wishes to try her hand at other projects before returning to the part of Carla Connor, a role she has enjoyed playing for nine years."
Before 42-year-old Alison leaves, we're promised some explosive storylines involving her feisty character.
The spokesperson adds: "Before Ali takes her break Carla has much more drama to come.
"At the end of this month she will be central to the explosive storyline which sees Victoria Court go up in flames, and the aftermath of that plotline will have huge consequences for the factory boss.
"Ali's desire to take a break from the show gives the writers the opportunity to come up with a enthralling exit for the character."
Alison's contract is said to expire in December.
She joined the soap in 2006, and has become one of the soap's favourite characters.
In 2010, Carla shot her estranged husband Tom Gordon after he kidnapped her and kept her hostage in the Underworld factory.
The following year she was raped by fiancé Frank Foster when she called off their wedding and she later tried to commit suicide.
Her storylines have also included a tragic miscarriage, a dramatic mini-bus crash and her brother Rob's handover to the police following Tina's murder.
Alison is nominated for Best Actress at the British Soap Awards later this month.
Actor Craig Charles has also announced he's leaving the cobbles to concentrate on filming Red Dwarf.
The actor will bow out on screen as Weatherfield cabbie Lloyd Mullaney in September after 10 years playing the character.
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