All of the Class I railway's business units reported revenue growth during the year, with five of the six groups reporting an increase in volumes. Wagon loadings increased by 3% compared with 2010 while freight revenue grew 15% to $US 18.5bn from $US 16.1bn in 2010.

During the year UP invested a record $US 3.2bn and generated record free cash flow of $US 1.9bn. The company says that 2011 was its most profitable year ever despite a 36% increase in average diesel prices from $US 0.5 per litre in 2010 to $US 0.69 in 2011.

"Looking ahead, we expect continued slow but steady economic growth in 2012," says Mr Jim Young, UP chairman and CEO.