Customers like them because they reseal and are lightweight, said Bea Perez.
The firm, which is one of the world's biggest plastic waste polluters, has pledged to recycle as many plastic bottles as it uses by 2030.
But environmental campaigners argue many Coke bottles would still go uncollected and end up in landfill.
The drinks giant produces about three million tonnes of plastic packaging a year - equivalent to 200,000 bottles a minute.
