Shares in major fertilizer makers tumbled, wiping out more than $9bn in stock market value, after Germany's K+S warned of "extraordinarily weak sales" and joined Canada's PotashCorp in axing further capacity.

K+S stock plunged 14%, slashing more than E1.1bn ($1.55bn) from its market capitalisation, after the group warned that 2009 revenues and earnings would suffer "further significant reductions" on top of the "tangible" declines it had already prepared investors for.

Sales of potash fertilizer would come in at 4.0m-4.5m tonnes for last year, down from a forecast of just under 6m tonnes made last month, after an uptick it had expected in demand failed to materialize.

'Very low demand'

"European agriculture exercised great restraint in the use of potash fertilisers in the spring," the group said.

"The demand for fertilizers remained very low in the [April-to-June period] as well."

The group said it was cutting the price of potassium chloride, a base for potash fertilizers, by 22% to E435 a tonne, viewing current prices as "unsustainable".

And it unveiled a cut of 2m tonnes in potash capacity to reflect the drop in sales.

'Extermely slow spring season' 

The announcement came hours after PotashCorp said it was mothballing an extra 800,000 tonnes of production this year, bringing total curtailments to 4.7m tonnes.

The Canadian group blamed the cut on an "extremely slow US spring season" and "extended negotiations" with foreign buyers.

The company added that it expected a rebound in demand in the second half of the year "as Brazil approaches its major application season and India and China inevitably return to the market".

Shares prices tumble

However, the group's shares slumped 10.5% to Can$108.34 in Toronto, slashing its market value by Can$3.7bn (US$3.3bn).

Other stocks dragged lower included Mosaic, which closed down 9.7% at $46.25, and Agrium, which lost 7.2% to Can$48.49 in Toronto.

Norway's Yara International ended 9.3% lower at NKR190.25 in Oslo, while Russia's Uralkali lost 10.9% to 102.20 roubles in Moscow.