Shares in Agrium tumbled 7% after the fertilizer group warned it would report a slump of up to 95% in third-quarter earnings, as a "slower than expected" revival in farm demand for nutrients took its toll.

The group, a member of the world fertilizer sector's top-10 companies, highlighted "significantly lower prices and margins" in all three major nutrients – nitrogen, phosphate and potash.

Its retail division, which also sells crop sprays, would report a "significant reduction" in earnings before interest, tax, depreciation and amortisation, with a 40% slump in fungicide sales also hitting home.

Weak trend 

Agrium, which is based in Canada, said the earnings fall of 90-95% it expected for the July-to-September period was "in line with" results from industry peers.

However, the revision, which implied earnings of $18m-$37m, surprised investors. Analysts had forecast Agrium would report earnings of $168m, according to Thomson Reuters.

Agrium shares closed down 7.1% at Can$55.52 in Toronto, wiping Can$660m from the group's stockmarket value.

Rain threat

The company added that its longer-term fundamentals were "excellent", with growers signalling a return to more normal fertilizer applications in 2010, after cutting back this year in response to lower grain prices.

Growers had been cheered by the revival in the price of corn, which closed above $4 a bushel in Chicago on Thursday for the first time since June.

However, Agrium added that a continuation of wet US conditions, which have set corn and soybean harvests back to their tardiest since records began, could delay market revival.

A shorter autumn fertilizer application season would be "expected to push fall nutrient demand into the spring of 2010".