Coca-Cola, PepsiCo and other US soft drink producers have agreed voluntary restrictions on sales in schools - the latest sign of mounting pressure on the industry to play a bigger role in tackling childhood obesity.

Soft drinks will be withdrawn from elementary schools and will be restricted in middle and high schools. The measures are a significant shift by an industry that has sometimes appeared reluctant to acknowledge health concerns about its drinks.

The agreement will increase pressure on Coca-Cola and its peers to take similar action in Europe where campaigns to ban soft drinks in schools are under way in several countries.

Susan Neely, president of the American Beverage Association, the industry group that brokered the deal, said producers would in future sell only water and fruit juice in elementary schools, would no longer sell full-sugar soft drinks in middle schools during the day and would ensure that no more than half the choices in high school vending machines were soft drinks.

Health campaigners say soft drinks are among the main causes of the obesity epidemic in North America where 16 per cent of children and teenagers are overweight, according to the US Center for Disease Control and Prevention.

According to the CSPI, the average US teenage boy consumes the equivalent of about 15 teaspoons of sugar a day through soft drinks.

Yesterday's announcement follows weeks of heated debate within the soft drink industry. Most executives support the move, led by Ms Neely, to confront the obesity issue but some fear the industry is being made a scapegoat and that the new policy will send a message to parents that children should never be allowed soft drinks.

School sales generate less than 1 per cent of revenues in North America for Coca-Cola Enterprises, the group's biggest bottler and distributor. But analysts said the greatest value of school vending machines was their ability to capture brand loyalty.