Campbell Soup Co (CPB.N) reported lower-than-expected quarterly sales and profit, hurt by higher promotions and weak demand for condensed soups, broths and V8 vegetable juices, and warned that its full-year sales could decline.

Shares of the company, which also sells Pepperidge Farm snacks and Prego pasta sauce, fell as much as 5.16 per cent to US$54 before the bell on Friday.

The company said it expects sales to be flat to down 1 percent compared with its prior forecast of flat to up 1 per cent.

Campbell, however, raised its adjusted profit forecast for the year to I$3.04-$3.09 per share from $3.00-$3.09 per share.

Net income attributable to the company fell to $176 million, or 58 cents per share, in the third quarter ended April 30, from $185 million, or 59 cents per share, a year earlier.

The company incurred pretax charges related to cost-savings initiatives of $7 million, or 1 cent per share.

Excluding certain items, the company earned 59 cents per share, missing analysts' average estimate of 64 cents per share, according to Thomson Reuters I/B/E/S.

Net sales fell to $1.85 billion from $1.87 billion. Analysts on average had expected $1.87 billion.

Organic sales dipped 1 per cent, reflecting higher promotional spending and low demand for its products in its Americas simple meals and beverages business, which sells its namesake soups and V8 vegetable juices.

The company said it continued to face product constraints in its Campbell fresh unit, following last year's voluntary recall of Protein Plus beverages.