* K+S to idle several plants, shorten working hours
* Says sees demand picking up in the second half of 2009
(Adds plans to shorten working hours at some plants, share price)
FRANKFURT, Dec 9 (Reuters) - K+S SDFG.DE plans to idle several fertilizer plants and shorten working hours to offset continued weak demand, the company said on Tuesday.
"As a result of the global financial crisis and decreased prices for agricultural products, worldwide demand for the fertilizers continues to be restrained," the company said.
Nonetheless, it expected demand to pick up again in the second half of 2009.
To cut back output, the world's fourth-largest potash miner planned to shut several plants on a week-by-week basis for several months. Other sites would shorten working hours.
Shares of K+S were down 0.3 percent at 32.70 euros at 0919 GMT, while the German blue-chip DAX index .GDAXI was off 0.5 percent.
K+S would shut down a plant employing 700 workers in Neuhof-Ellers near the central German city of Fulda for about four weeks from Dec. 20, a spokesman for the company said.
Three other plants would be affected by shutdowns and all others could shorten their working week in the first half of 2009, the company said.
K+S, which is also the world's second-biggest salt maker, already said at the end of October it would cut potash output by 400,000 metric tonnes at its German sites in the fourth quarter, citing lower-than-expected orders from fertiliser makers.
The company has toned down its outlook for this year after the financial crisis put an abrupt end to a boom in agricultural commodities, suppressing fertiliser demand.
"K+S takes the view that the fertilizer stocks still available on the market will have been used up by agriculture in the middle of 2009, so that for the second half of the year the demand for potash products should again pick up perceptibly," K+S said on Tuesday. (Reporting by Maria Sheahan and Frank Siebelt; Editing by Hans Peters)