The figures for the first quarter of 1996 showed that while sales of Dr Pepper rose by 5 per cent, sales of the Seven Up brand fell by 2 per cent and other brand sales declined by a similar figure.
The company said that Seven Up sales were affected by the delisting of the drink by certain Coca Cola and Pepsi bottlers. Another factor has been aggressive marketing of rival brand Sprite by Coca Cola.
Commenting on the figures, John Brock, managing director of Cadbury Schweppes' beverages division, said: "Overall, our plus 1 per cent volume growth performance in US soft drinks is better than in the same period last year and we are encouraged by these results."
Cadbury is ranked third in the US soft drinks market behind Coca Cola and Pepsi.
Its figures followed an 8 per cent rise in earnings from PepsiCo, whose figures were announced on Tuesday. The rise was led by strong sales of US drinks. Case sales grew by 6 per cent, boosted by double digit growth from Mountain Dew and solid growth from Pepsi.
Cadbury Schweppes shares slid back 10p to 513.5p on the quarterly figures. One analyst said: "The Dr Pepper figures weren't good enough after the Pepsi report on Tuesday."
The Americas account for 60 per cent of Cadbury's soft drinks sales and 30 per cent of group turnover.
In March John Sunderland, the new Cadbury Schweppes chief executive, announced a 16 per cent increase in full year profits to pounds 592m. The company then said that it could afford a pounds 1bn-pounds 2bn acquisition following the pounds 623m sale of its stake in Coca Cola Schweppes Beverages.
Cadbury increased its advertising spend from pounds 681m to pounds 738m last year with a large amount of the increase put behind the Seven Up brand.