Aug 9 (Reuters) - Brickworks Ltd said on Monday that it had temporarily cut 30% of its total brick output, as the recent COVID-19 related lockdowns in Australia curtailed construction activity in various states and pummelled demand for building materials.

Shares of the company fell as much as 5.6% to A$23.75 ($17.42) and were on track to post their biggest single-day drop since March 31, 2020.

The company said its brick sales plummeted almost 80% during the pause in construction across Sydney in late July, after holding relatively steady earlier that month.

"These were the most severe restrictions that our business has faced since the onset of the pandemic," said Lindsay Partridge, managing director, in a statement.

He added that despite a partial restart of construction activity this month, brick sales were only at 50% of pre-lockdown levels.

Sydney, Australia's largest city and the capital of New South Wales state, is nearing the seventh week of a nine-week lockdown, with authorities struggling to quell outbreaks of the Delta variant.

Brickworks warned the restrictions in New South Wales, its largest market, were having a material impact on earnings, but said it was unable to quantify the impact yet.

However, the hit would not be material to its fiscal 2021 results, the company said.

Brickworks, which listed in 1962, clarified that while it had temporarily reduced staffing across several manufacturing facilities, it had no intention of laying off any staff.

($1 = 1.3633 Australian dollars)

(Reporting by Savyata Mishra in Bengaluru; Editing by Amy Caren Daniel)