US drinks corporation, Coca-Cola, is planning to launch diet version of Vanilla Coke, the line extension it launched earlier in the summer, according to press reports in the US. The new variant is reportedly set to make its debut in September or October. Coca-Cola would not comment on the subject but Coke bottlers in the US are known to be keen to see a diet version of Coke Vanilla which has been selling well since its introduction in May.