The decline in U.S. carbonated soft drink consumption accelerated last year as fast-growing energy drinks failed to offset weakness in traditional sodas from Coca-Cola Co and PepsiCo Inc, a beverage industry newsletter said on Tuesday.

Total sales volume of soda fell about 1 percent in 2011 to 9.27 billion cases, according to Beverage Digest, about the same level it was in 1996. Sales volume fell 0.5 percent in 2010.

Excluding energy drinks such as Red Bull and Rockstar, soda volume was down 1.5 percent last year, Beverage Digest said.

Carbonated soft drink sales in the United States grew about 3 percent annually throughout most of the 1990s but began to slow in 1999. Sales have been in decline since 2005 as increasingly health-conscious consumers turn to options they see as healthier, such as bottled water, juice and tea.

Beverage Digest estimates that prices were up about 3 percent last year as manufacturers sought to pass through some of the increase in costs of raw materials including corn syrup, used as a sweetener. Those price increases likely contributed to the volume weakness.

Coke shares were down 6 cents to $70.34 on the New York Stock Exchange, while Pepsi shares were down 7 cents to $64.66. Dr Pepper Snapple Group Inc, the No. 3 soft drink company, saw its shares fall 17 cents to $38.49.