Cummins will continue in post until the end of December leading the construction business to ensure an orderly transition and handover.
Cummins joined Kier in 2019 from Laing O’Rourke where he was UK Buildings director and worked for 16 years.
Stuart Togwell, the Group’s Commercial Director, will take up the role of Group Managing Director, Construction from the New Year.
Togwell arrived at Kier in 2019 after three decades at Wates.
Andrew Davies, Kier Group CEO, said: “I would like to thank Liam for his hard work over the past three years. Liam has been an integral part of our leadership team and I wish him every success in the future.
“I am delighted that Stuart Togwell, currently Group Commercial Director and a valued member of the Executive Committee, assumes the position of Group Managing Director, Construction.
“Stuart’s wealth of experience in the construction sector, as well as his focus on operational and commercial excellence and his people-first approach, mean he is well-placed to lead our Construction business and help to deliver our medium-term plan.”