Sibley decided to step down from the partnerships homes group due to the removal of his current role of chief operating officer.
He has been with the business since April 2015, and will step down as a director with immediate effect but will support an orderly transition of his responsibilities until the end of the year.
Vistry said the change reduced the length of reporting lines and ensured closer proximity of Greg Fitzgerald chair and CEO to the business.
Sibley was previously Vistry Group CFO and became COO in November.
The restructure of senior responsibilities comes after Vistry delivered two profit warnings over build-out costs on schemes in its southern division, now expected to cost £165m more than expected.
An internal review blamed the region’s problems on “insufficient management capability, non-compliant commercial forecasting processes and poor divisional culture.”
Since the first profit warning Vistry’s share price has nearly halved to 671p
Yesterday Vistry issued a statement to the markets after it revealed one in five shareholders voted against re-election of Fitzgerald in May.
The housebuilder in May made Fitzgerald executive chair of the business in addition to chief executive, in a departure from the UK Corporate Governance Code.
Commenting on the latest board changes, Fitzgerald said: “Earl has been an integral part of our operational and executive team and his leadership and contribution have been significant in helping to establish Vistry as a leading housebuilding and partnerships business.
“Having worked with Earl since I joined Bovis in 2017, I am very grateful for his dedication, support and hard work during his time with us. He will leave with our best wishes for the future.”