The Lotteries Commission's first-half profit and sales fell sharply after it missed out on two lucrative Powerball jackpot runs and an advertising rebranding campaign fell flat.

The commission reported revenue of $305.9 million in the six months to December 31, down 10.7 per cent on the same half a year earlier, when the "exceptional" jackpot runs boosted revenue.

Profit fell 19.2 per cent to $61.7 million, due partly to the fall in revenue and partly due to a 23 per cent rise in costs to $23 million. The sharply higher costs were linked to the commission's first big revamp of its main Lotto product in 17 years and an expansion of its retail network.

However, Lotto sales fell 8.6 per cent to $154 million because of the lack of the Powerball jackpots.

The commission said Lotto had performed well since the revamp in August and sales had been boosted by its triple dip promotions.

Instant Kiwi sales rose 9.5 per cent to $53.3 million, while Keno sales rose 8.3 per cent to $11.8 million.

NZ Lotteries chief executive Trevor Hall said a very strong sales performance in December had helped bring the result into line with budgets. "The jackpot runs were statistical abnormalities, and jackpots in the current period have followed a more typical jackpotting pattern, only exceeding $5 million for 5 weeks compared with 16 weeks the year before."

The commission said an advertising campaign had worked well at educating players about the changes, but the brand aspect of the campaign was not as well received.