The Government has told four private schools they cannot join the state sector, after a rise in integration applications.
They were among 12 schools being considered for integration since February last year.
Education Minister Anne Tolley is yet to decide on applications by five schools, while another two have withdrawn their applications.
Only one school - the Sancta Maria Catholic School in Manukau, which opened this year - has been successful.
The school's buildings remain in private ownership but the Government meets many of the costs, including teacher salaries.
Of nearly 2600 schools, about 330 are integrated and 96 are private.