12:30 PM EST - Potash Corp. : shares fell after the fertilizer giant lowered its 2008 profit guidance due to wilting demand for crop nutrients amid the slowing global economy. It also has issued layoff notices to more than 900 employees, after announcing last week it would cut production by 20 percent beginning next month. Potash Corp.
shares T.POT are trading down $1.90 at $88.10.
