NEW YORK (Standard&Poor's) July 28, 2010--Standard&Poor's Ratings Services today assigned its 'BBB' rating to Union Pacific Corp.'s $500 million senior unsecured notes due 2021. Omaha, Neb.-based Union Pacific will use proceeds from the debt issue for general corporate purposes, including working capital, capital expenditures, and the repayment of indebtedness and commercial paper. The freight railroad has $9.4 billion of debt reported as of June 30, 2010. The ratings on Union Pacific reflect the favorable risk characteristics of the U.S. freight railroad industry, as well as the company's strong competitive position and its moderate financial policies. Price competition from other railroads and trucking companies in selected commodities and the capital intensity of the industry somewhat offset these