Woolworths said converting all its stores to the Countdown brand gives it the opportunity for enhanced marketing and promotions.
Its gross margin in New Zealand widened 37 basis points to 22.64 per cent in the latest 52 week period, while its ebit margin was unchanged at 4.71 per cent.
The result was achieved "in challenging economic conditions," made worse by the Christchurch earthquake, the retailer said.
The February 22 quake shuttered seven Countdown and franchise stores in the city, though since then four have re-opened.
Woolworths has 156 stores in New Zealand to Foodstuffs' 680 outlets, which include supermarkets, convenience stores and liquor outlets.
Woolworths also owns the Dick Smith chain in New Zealand and Australia.
In New Zealand, consumer electronic sales fell 5.6 per cent to $322 million in the latest year, but its ebit margin shrank 140 basis points to 1.74 per cent and ebit tumbled 48 per cent to $5.6 million.
The business "continues to be challenged with the weak economic environment impacting discretionary retailers together with strong price competition and significant price deflation, the company said.