FORT WORTH , Texas , April 23 / PRNewswire-FirstCall / -- RadioShack Corporation ( NYSE : RSH ) today announced preliminary net income for the first quarter ended March 31 , 2009 , of $ 43.1 million , or $ 0.34 per diluted share , compared with net income of $ 38.8 million , or $ 0.30 per diluted share , for the first quarter ended March 31 , 2008 .