Coca-Cola is making additional investment in Virent's bio-based paraxylene BioFormPX demonstration facility in Wisconsin, US.
Virent has said that the investment will help in scaling up separation and purification of BioFormPX at the plant.
The two companies have first signed a joint development and supply agreements for paraxylene technology in 2011.
Coca-Cola plantbottle innovation platform general manager Scott Vitters said: "Over the course of our work together, Virent has continuously delivered on their commitments and advanced their technology.
"That progress supports building additional capability for Virent and advances us on the path to a full-scale commercial solution for our 100% plant-based PET plastic packaging."
Coca-Cola has used the PX to produce 100% bio-based PET bottles. This new investment will help the company to produce larger quantities of BioFormPX material.
Virent CEO Lee Edwards said, "The Coca-Cola Company continues to be a valued partner for Virent. Their intention to use our BioFormPX material in the next generation of PlantBottle packaging is critical in attracting manufacturing partners from the PET supply chain.
"This - along with the progress we have made in our joint development work - moves us closer to seeing the first commercial 100% bio-based PET bottles on retail shelves made using Virent technology."
Virent's patented technology converts plant-based materials into products that are similar to those made from petroleum, such as gasoline, diesel, jet fuel, and chemicals for plastics and fibers.
Apart from Coca-Cola, Virent is partnering with companies like Cargill, Honda and Shell to develop its BioForming technology platform.