Port users are beginning to voice concerns about a mooted merger between the New Zealand’s two major container gateways – northern neighbours Port of Tauranga and Ports of Auckland.Shipping companies in particular are fearful that they will lose all bargaining rights if a monopoly is created. Vigorous debate can be expected if the proposal goes, as expected, for Commerce Commission scrutiny next year.Further announcements are expected to be made before the end of then year.