Deere & Co. on Wednesday posted a lower quarterly profit and cut its full-year forecast as farmers facing falling income as a result of declining grain prices continued to pull back on purchases of the company's tractors, harvesters and other machinery.

The Moline, Illinois-based company, the world's largest maker of ag equipment, said it now expected to earn $3.1 billion in fiscal 2014, down from its previous forecast of $3.3 billion, because of falling farm income in the United States, among other factors.

The company said it expected total U.S. farm cash receipts, which correlate closely with investment in new farm equipment, to fall to $387.1 billion in 2014, down from $407.1 billion in 2013 and below its previous forecast of $392.7 billion.

The company also cut its forecast for South America, where rising interest rates in Brazil and tight credit in Argentina are hurting sales.

Deere said it now expects full-year industry sales in the region to fall 15 percent in 2014, down from a previously forecast decline of 10 percent.

The company also repeated the warning it issued earlier this year that sales in the countries that once formed the Soviet Union would be "down significantly" in 2014 as a result of "geopolitical uncertainty" in the region.

In a statement, Deere Chairman and Chief Executive Sam Allen said the company was scaling back production in line with falling global demand for its agricultural products.

"These actions illustrate our commitment to responding with speed and decisiveness to changes in market conditions," Allen said.

The one bright spot in Deere's core farm market was the U.S. livestock sector, where the company said rising meat and poultry prices were driving sales of smaller tractors and helping to moderate the weakness in the grains sector.

For the most recent quarter ended July 31, Deere reported a net profit of $850.7 million, or $2.33 a share, for the third quarter ended July 31, compared with $996.5 million, or $2.56 a share, a year earlier.

Sales fell 5 percent to $9.5 billion.

Analysts on average expected Deere to post a profit of $2.22 a share on sales of $8.75 billion, according to Thomson Reuters I/B/E/S.

The stronger-than-expected quarterly profit resulted from sales of the company's construction and forestry equipment, which benefited from a rebound in U.S. nonresidential building.

Shares of Deere were down 1 percent at $85.60 in premarket trading.