Operating earnings of $184million were $11million higher than the previous corresponding period but $11 million lower than Forsyth Barr's forecast, broker Suzanne Kinnaird said.
The interim dividend was increased 1c per share to 21cps, in line with expectations.
Normalised profit of $68million was $1million better than the pcp but $8million lower than forecast. The main issues were higher costs which came in $17million more than forecast, she said.
''Margins were worse than expected, which was a risk given the high level of customer growth.''
Marketing costs were $5million more than forecast and other operating expenditure was also $5million higher than forecast, she said.
''On the positive side, customer growth continues to be strong and the gas and telecommunications contributions have grown.''
The result included a $6.1million hit from the impact of a Inland Revenue ruling on the way Trustpower treated expenditure on feasibility studies in the past.
The cost could be reversed if the Infratil controlled company succeeded in an appeal to the Supreme Court next March. Ms Kinnaird said TPW had fully provisioned against a loss of the court case.
The company continued to develop its Australia wind options. It had three projects going through the consenting process with the first decision due by the end of the year, on its Dundonnell project in Victoria.
Australian wind continues to be the main source for future growth potential for TPW, she said.
The company would repay $100million of subordinated bonds maturing in December from undrawn bank facilities.
Total electricity customer accounts rose to 252,000 from 234,000 at September 30 last year, while telecommunications customers rose to 51,000 from 35,000 as Trustpower's strategy of offering bundled packages of electricity, gas and telecommunications spread through the customer base.
About 66,000 customers had two or more services with Trustpower at balance date, a 46% increase on the same time last year, and the company reported lower customer churn rates than the market average.
