Amid stagnating sales of carbonated beverages, Coca-Cola Co. is working on developing a line of milk-based beverages for children under 12, according to the Wall Street Journal. The paper reported that a plan, code-named "Project Mother," will test "five plus" milk-based drinks, hoping to tap into the $30 billion U.S. milk market.According to Coca Cola any milk-based beverage would have to combine taste and nutrition, the paper said. Children spend about 30 to 40 per cent of their annual per capita income, about $200 to $600 per year, on foods and beverages, the paper continued. Shares of Coca-Cola rose $1.12 to $60 in New York Stock Exchange trade Tuesday.