By Derek Rose in Sydney

Woolworths suffered a big drop in half-year profit amid a 17-day industrial action in the lead-up to Christmas.

Australia’s biggest supermarket chain on Wednesday said it made $739 million in net profit after tax in the six months to December 31, down 20.6 per cent from a year ago.

Sales across the group, which includes Big W, Petstock and its New Zealand supermarkets, rose 3.7 per cent to $35.9 billion.

Group earnings before interest and tax were down 14.2 per cent to $1.4 billion.

Chief executive Amanda Bardwell said Woolworths’ Australian supermarket team had worked “incredibly hard” to recover from the supply chain disruptions stemming from the strike at four locations in Victoria and NSW in November and December.

“We came to an agreement that is fair and sustainable and enables ongoing productivity improvements critical to maintaining competitiveness,” she said.

Sales in Victoria still have not yet fully recovered, Ms Bardwell said, but availability and customer metrics were returning to their pre-disruption levels.

She said Woolworths expects the Australian Consumer and Competition Commission would soon release its final report about its inquiry into the supermarket sector.

Ms Bardwell said Woolworths had assisted the commission in its inquiry and would carefully review the report.

“Our day-to-day experience is that the Australian grocery sector is highly competitive, and that customers have many choices about where to shop,” she said.

Woolworths will pay a 39 cent per share dividend, down 17 per cent from a year ago.

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