US chocolate maker Hershey's first-quarter net profit rose 7% to $121m on net sales up just 0.6% for the period.

Investors were disappointed with the figures. Terry Bivens, an analyst at Bear Sterns, said: “This is the least impressive quarter for a long time, with both revenue and gross margin lines coming in below expectations.”

The group added that it was planning to accelerate product development and to expand its dark chocolate, cookies and single-serve, snack nuts ranges.