By Stuart Condie

SYDNEY--Woolworths Group Ltd. has blamed empty store shelves and delays to customers' grocery deliveries on staff absences driven by Australia's surging Covid-19 cases.

Chief Executive Brad Banducci on Friday said more than 20% of staff at Woolworths' distribution centers and 10% of staff at its stores were absent due to the pandemic.

Woolworths already said last month it expects first-half earnings from its Australian food business to fall by as much as 9.2% largely due to between 210 million and 220 million Australian dollars (US$150.5 million-US$167.4 million)of Covid-related costs.

Mr. Banducci said stock levels remained healthy but the retailer, which operates supermarkets and department stores, was struggling to fill gaps on shelves.

"Unlike the surge buying of early 2020--who could forget the toilet paper--this is because of the number of people in our supply chain in isolation, from suppliers to truck drivers and distribution centre team members, which in turn is causing material delays to store deliveries," Mr. Banducci wrote in an email to customers.

Mr. Banducci said it was unclear when supply chains would normalize.

Australian states are reimposing various restrictions. The country reported about 72,000 new Covid-19 cases on Thursday.

Write to Stuart Condie at stuart.condie@wsj.com

(END) Dow Jones Newswires

01-06-22 1849ET