ConAgra Foods has been in talks to sell its frozen potato unit to cereal maker Post Holdings, according to a report. The Wall Street Journal reported Tuesday that the talks had stalled but could revive. The report cited unidentified sources. If a deal went through, it would be one of the largest recent mergers in the consumer goods industry and the largest yet for St. Louis-based Post, which has been on a run of acquisitions. ConAgra said last year that it would spin off the Lamb Weston potato unit into a new company, called Lamb Weston, with ConAgra shareholders getting shares in the new company. More