(Reuters) -Railroad operator Union Pacific reported a 7% increase in fourth-quarter profit on Thursday, helped by more grain and fertilizer shipments and core pricing gains.

The company posted a net income of $1.76 billion, or $2.91 per share, in the fourth quarter, compared with $1.65 billion, or $2.71 per share, a year earlier.

The Omaha, Nebraska-based company's shares rose 4% in premarket trading.

Union Pacific, seen as a bellwether for the U.S. economy, has benefited from improving revenue in its grain segments following higher West Coast imports and a strong harvest season.