Australian-owned New Zealand supermarket chain, Countdown, has boosted first-half earnings as it nabs market share and customer numbers in what it says is a subdued environment.

Countdown’s earnings before interest and tax rose 1.3 per cent to $NZ164.4 million ($A155.10 million) in the 27 weeks ended January 5 with sales up 2.6 per cent to $NZ3.02 billion, its ASX-listed owner, Woolworths, said in a statement on Friday.

In Australian dollar terms, earnings rose 9.7 per cent to $A136.8m and sales were up 15 per cent to $A2.67b, assisted by a favourable exchange rate for converting New Zealand to Australian dollars.

“We continued to increase market share, customer numbers and items sold, reflecting the relevance of our offer and success of promotional activity,” the company said.

“This was despite the subdued grocery market conditions, highly competitive marketplace and price deflation across a number of key categories.”

The Countdown chain has been accused of anti-competitive and corrupt behaviour by Labour MP Shane Jones under the cover of parliamentary privilege.

The Commerce Commission is formally investigating the claims, which it says will take a number of months.

Countdown has previously denied the allegations and said it would co-operate fully with the inquiry, although Woolworths made no mention of the action in Friday’s announcement and accompanying releases.

The grocer is now New Zealand’s largest supermarket chain, and continues to expand, opening two new stores in the reported period and plans to open a further five stores by the end of the financial year.

It also intends to continue to reduce prices in New Zealand, according to presentation slides accompanying the release.

BusinessDesk