U.S. Sues Sears, Alleging Racial Bias  NEW YORK (Reuters) - Sears, Roebuck   Co. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=S.N target=/stocks/quickinfo/fullquote"&gt;S.N&lt;/A&gt;, was sued  this week by the U.S. Equal Employment Opportunity Commission,  which said the largest U.S. department store chain illegally  fired a store manager because he was black.