ConAgra Foods came under even more pressure to start delivering returns to shareholders last week when activist investor Jana Partners revealed it has taken a stake in the US food company. Shareholders have long grumbled about the seeming incompatibility between ConAgra's branded and private-label business, with shares in the under-performing US food maker at all time highs on the expectation that disposals must soon come. Are there more options open to ConAgra management than simply carving up the business? Katy Askew investigates.