OMAHA, Neb. — Union Pacific's fourth-quarter earnings report will show how the railroad handled last fall's peak shipping season and provide clues about the strength of the U.S. economy.

WHAT TO WATCH FOR: Investors will be looking for details about which of Union Pacific's business sectors performed best during the fourth quarter and how much the railroad paid for fuel. The Omaha-based company will release its report Thursday morning.

Credit Suisse analyst Christopher Ceraso said in a research note that Union Pacific hauled 3.7 percent more carloads of cargo during the fourth quarter, according to data from the American Association of Railroads. The carload totals for Union Pacific in the fourth quarter, which peaked around 185,000 carloads a week, remained below the railroad's capacity of about 200,000 carloads a week.

Raymond James analysts Patrick Brown and William Fisher said Union Pacific finished the year strong. They said the railroad hauled more freight than expected in the fourth quarter while limiting hiring. That should help Union Pacific's earnings.

Deutsche Bank analyst Justin Yagerman thinks Union Pacific is ready for a profitable 2012 because the railroad should be able to increase prices on a number of its long-term contracts when those come up for renewal.

Yagerman said Union Pacific renegotiated contracts worth about $750 million late in 2011, and it is due to renew about $300 million more in contracts in 2012. He said the railroad will also be helped by growth prospects in its intermodal and coal-shipping businesses.

WHY IT MATTERS: Investors watch Union Pacific's results closely, because the major freight railroads are considered gauges of the nation's economic health. Railroads carry cars, chemicals, crops, containers of imported goods and lumber across the nation, so railroad profits are tied to the health of those industries. Union Pacific is the nation's largest railroad. It operates 32,400 miles of track in 23 states between the West, the Midwest and the Gulf coast.

WHAT'S EXPECTED: Analysts surveyed by FactSet expect Union Pacific to report earnings per share of $1.81 on revenue of $5.04 billion.

LAST YEAR'S QUARTER: Union Pacific reported net income of $775 million, or $1.56 per share, as the U.S. economy began to slowly strengthen. The railroad generated $4.4 billion revenue during the fourth quarter of 2010.

Union Pacific Corp.