Union Pacific Corp., the biggest U.S. railroad, posted a higher second-quarter profit on Thursday as increased freight rates offset lower volumes.

The company earned $1.1 billion, or $2.37 per share, up from $1 billion, or $2.10 per share, a year earlier.

Revenue rose to $5.5 billion from $5.2 billion.

Union Pacific shares closed at $159.70 Wednesday on the New York Stock Exchange.