Published Tuesday, 05 January 2010
The high-flier, played by Maxwell Caulfield, will be bumped off in an hour-long episode to be screened next Thursday, January 14.
Soap bosses had already announced Caulfield was to leave but had kept viewers guessing about how he would go until now.
However they are keeping tight-lipped about the identity of the killer, who will be revealed in the episode.
There are many characters who could have a motive. Potential culprits include Mark's wife Natasha (Amanda Donohoe), who next week discovers he has been cheating on her with his other wife Faye Lamb (Kim Thomson).
Faye is also in the frame, having had her life turned upside down by Mark more than once.
And, reeling from the discovery they are related, Mark's children Ryan Lamb (James Sutton) and Maisie Wylde (Alice Coulthard) may be hell-bent on getting revenge on their father for allowing them to fall in love.
Mark's other son Nathan Wylde (Lyndon Ogbourne), who has a track record in twisted behaviour, could also be the one to teach his spineless father a lesson.
Caulfield, whose dramatic exit comes after a year in the soap, said of his time in the show: "It's been one of the best experiences of my career and I've had the opportunity to work with the loveliest group of people. To have the privilege of working with two knockout actresses on a daily basis made Mark really fun to play."