CF Industries Holdings, Inc. (NYSE: CF), a leading global manufacturer of hydrogen and nitrogen products, today informed customers it serves by Union Pacific rail lines that railroad-mandated shipping reductions would result in nitrogen fertilizer shipment delays during the spring application season and that it would be unable to accept new rail sales involving Union Pacific for the foreseeable future. The Company understands that it is one of only 30 companies to face these restrictions. CF Industries ships to customers via Union Pacific rail lines primarily from its Donaldsonville Complex in Louisiana and its Port Neal Complex in Iowa. The rail lines serve key agricultural areas such as Iowa, Illinois, Kansas, Nebraska, Texas and California.