Woolworths Australia yesterday posted a 4.8% increase for its Woolworths, Countdown and Foodtown New Zealand supermarkets.

The ASX-listed company's first quarter results, to October 4, shows sales of $NZ1.3 billion for the company's New Zealand supermarkets and comparable sales of 4.5%, indicating a positive response to its new formats, improved ranging, private label and stock improvements, it said.

Overall food inflation, of 4.3%, reflected easing cost price pressure on produce, perishables and bakery items, the company said.

Overall, Woolworths reported sales of $A13.4 billion in the first quarter, up 7.4% exclusing petrol sales and 4.2% including petrol sales.

Chief executive Michael Luscombe said the result was a solid start to the financial year, reflecting its continued focus and investment to deliver value and enhance the customer experience.