The Education Minister Hekia Parata has confirmed that up to 50 teaching positions will be lost in the shake-up of Canterbury Schools.

Ms Parata's interim decisions were that seven schools will close and 12 will merge.

She said staff at the schools earmarked for change will have to reapply for their positions.

"Teachers would have the opportunity to reapply for jobs in the merged schools but it is in the principal's own contractual agreements that roles for principals must be advertised externally," she said.