Credit ratings company S&P said it has elevated its monitoring of Omaha-based ConAgra Foods, a status S&P calls "CreditWatch." The credit-ratings action comes after ConAgra said Tuesday that it plans to sell the St. Louis-based company division that makes grocery-store branded items such as peanut butter and canned soup. The employer of 2,600 people in Nebraska and western Iowa is under pressure from activist investors to cut costs, boost sales and increase profit margins.