The ASX-listed company said "prolonged COVID-19 impacts", particularly in developing markets, trimmed ammonium nitrate (AN) volumes by 1% yoy to 3.93 million tonnes, and 4% without new Exsa volumes in South America.

Capex of $472 million, including $78 million of rectification works at Burrup, compared with $424 million in FY19.

Orica's net debt climbed $200 million over the latest year to $1.8 billion, with interest costs up $40 million to $150 million in FY20.

"Following a strong first half, momentum into the second half was disrupted by the COVID-19 pandemic which led to lockdowns and lower levels of mining activity in many countries across our markets," the company said.

"As a result, full year AN volumes were down 4% … excluding 98 thousand tonnes sold by the recently acquired Exsa business since acquisition in May 2020. Including Exsa, AN volumes were down 1%.

"While volume growth in Australia remained strong through the pandemic and mining activity in the USA was resilient, other geographical regions were impacted to varying degrees, and most severely in developing countries. Other structural impacts affecting the business include weakening and uncertain coal markets - particularly in the USA and Indonesia."

Orica shares were down 4.5% today at $16.21, capitalising the company at $6.65 billion. Its share price is down more than 26% since the start of 2020 and the company's market value has dropped by nearly one-third since the onset of COVID restrictions.