Following Premier Foods' full-year profit warning on Friday - which drove its share price down 37% - Investec has placed its hold rating and 15p target price under review but warned investors to avoid the stock.In an unscheduled third quarter interim management statement, the food manufacturer revealed that since its third quarter performance has been significantly under expectations, full-year trading profits will be below market expectations."The critical question facing Premier and its shareholders this morning is whether the company can survive and whether there is any value left in the equity at all," according to analyst Martin Deboo."To say that all this adds up to a baptism of fire for new chief executive officer Mike Clarke feels like the understatement of the year," he said. Shares were 37.2% down at 6.28p by 12:31, significantly lower than their 52-week high of 35.12p.BC