Infratil has downgraded its operating profit guidance for the year just completed to between $490 and $500 million.
The infrastructure investor cites weaker trading in the New Zealand energy and transport markets and the impact of the weaker Australian dollar.
Previously, Infratil predicted a result between $500 and $540 million for the year ended March.
The downgrade is despite interest costs falling to between $180 and $195 million from a forecast $195 to $205 million.
However, operating cash flow is expected to be at least $40 million higher.