Amcor's gloomy outlook followed a hefty profit decline that was exacerbated after it lost revenue from discontinued operations and spent money on restructuring.
Statutory net profit fell 51.5 per to $258.8 million for the year ended June 30, down from $533.7 in the previous year.
Overall sales fell 14.3 per cent to $9.3 billion from $10.9 billion in the previous year.
Stripping out a number of significant items that relate to its three-year turnaround program, Amcor posted an after tax profit of $369.1 million.
That result was seven per cent down on last year's result but still better than some analysts had forecast.
Chief executive Ken MacKenzie said the company's earnings - derived from its continuing businesses, before tax and interest costs and expressed in constant currency terms - actually showed 9.4 per cent growth.
The increase was a result of the company's restructure and would provide "momentum" in the current year, he said.
"There is evidence however, that global economies are slowing and this could impact the growth in sales," he said.
"Amcor's businesses are relatively defensive with over 90 per cent of sales into the consumer stables sector, specifically food, beverage, tobacco packaging and healthcare.
"Inflationary pressures are increasing, with the impact of higher oil prices flowing through to input costs and higher cost inflation in most countries."
Amcor's profit was dented by $32 million impact from a high Australian dollar exchange rate.
Around 80 per cent of Amcor's earnings are generated offshore, mostly in North America and Europe.
As well while last year's balance sheet was boosted by a $136.7 million gain in its significant items, this year the ongoing restructuring of the company's global operations caused a $110.3 million loss.
Amcor's core polyethylene or PET global packaging business had a strong year, with earnings before interest and tax up 29.3 per cent to $US198.8 million.
The business benefited from higher volumes and as operations in both North America and Latin America improved from 2006/07.
"Earnings are anticipated to improve in the current year, however growth will be substantially lower than the 29.3 per cent achieved in 2007/08 and is dependent on the impact a slowing US economy may have on volume growth," McKenzie said.
It declared a flat final dividend of 17 cents, taking the total for 2007/08 to 34 cents, the same amount it paid out last year.
