Gas trading ebitda fell to $14.6m from $20.8m, largely because of lower gas volumes and margins, but also affected by the sale of Vector's Kapuni gas processing plant to Todd Petroleum Mining last year.
Total capital expenditure in the first six months was $260.7 million, up $20.7 million or 8.6 per cent on the prior period.
Chief executive Simon Mackenzie said this reflected the company's continued investment in infrastructure to support network integrity, Auckland growth, increasing deployments of advanced meters, commencement of 4G modem upgrades across New Zealand's advanced meter base, increasing stock levels to counteract risks associated with global production shortages linked to COVID-19.
"We continue to invest in cyber security working with our specialist global partners."