Union Pacific Railroad has canceled three express train contracts with United Parcel Service and is increasing some shipping prices to handle growing demand in the midst of a train crew shortage.

A contract for trains that ran once a week each way from Los Angeles to New York has been canceled because it took up resources needed in other areas of the railroad, Union Pacific spokeswoman Kathryn Blackwell says.

The service began in July as a partnership with CSX Transportation. Union Pacific suspended the service for April as it dealt with congestion on its 23-state system. Two other contracts with UPS for expedited service from Los Angeles to Dallas and Memphis also were suspended.

During the suspension, Union Pacific paid UPS for the added costs of drivers, gasoline and other expenses of putting those items on trucks, Blackwell says.

Late last week, the railroad told UPS the contract for service between Los Angeles and New York would be canceled, UPS spokesman Norman Black said. However, contracts for service between Los Angeles, Dallas and Memphis were expected to resume sometime this month.

Some shipping prices also will be increased by Union Pacific, senior vice president Bob Turner says. "It's being looked at on a customer-by-customer basis," Turner says. "If demand for our product is outstripping our supply, then a tool to bring supply and demand into balance is a price increase."

Union Pacific has said it was surprised by the economy's strong comeback and burgeoning demand this year and it has begun hiring more train crews and buying more locomotives.