The stakes were sold to a joint venture between HICL Infrastructure Company and Kajima Partnerships and sees Kier make a £4.3m cash profit on the original investment.
Kier constructed the schools and has also provided the schools with facilities management services for several years.
Following the disposals, Kier will continue to provide the facilities services under the current contracts for a further 21 years in the case of the Norwich schools, and 22 years in the case of the Oldham schools.