NEW YORK (Standard&Poor's) April 17, 2012--Standard&Poor's Ratings Services today said its ratings and outlook on U.S. Bancorp (USB; A/Stable/A-1) are not affected by the company's strong first-quarter earnings, given the current operating conditions. The company posted Standard&Poor's-adjusted pretax earnings of $1.83 billion, up from $1.59 billion the previous quarter and $1.4 billion the prior year. In the first quarter, adjusted revenue increased 1.8% from the previous quarter and 10.2% year over year because of an increase in average earning assets and fee-based income. The net interest margin (NIM) was unchanged from the fourth quarter at 3.60% as a reduction in cash at the Federal Reserve and a change in the classification of credit card