Industry giant, Deere & Co has warned of an accelerating decline in the global farm equipment market as it forecasts a 40 per cent tumble in earnings over the next year, a bigger drop than Wall Street had expected.

The maker of John Deere machinery unveiled results for the August-to-October period, the fourth quarter of its financial year which, while down 10.6 per cent at $3.16bn, exceeded market forecasts.

The results were equivalent to $1.83 per share, ahead of the $1.57 per share that analysts had pencilled in.

Samuel Allen, the Deere & Co chairman and chief executive, said the company had achieved a "solid performance in spite of weaker conditions in the global farm sector", for which profits are being undermined by lower crop prices.

However, the group cautioned of a deepening decline in the ag machinery market, expecting the group's own sales in the sector to fall by 20 per cent in the year to October 2015.

Deere reported a drop of 9 per cent in sales in the year to the end of last month, and 13 per cent in the August to October period.