The nations have signed up to be part of the new Marine Plastics Research and Innovation Framework, a hub where researchers will be able to connect and collaborate to develop solutions to stop plastic waste from entering the oceans and find environmentally-friendly alternatives to plastic.
The UK is contributing £25 million and will play a leading role in designing and running the Framework.
The British Plastics Federation, which represents more than 500 businesses, the Ellen MacArthur Foundation, the Waste and Resources Action Programme (WRAP) and engineering giant Mott MacDonalnd are among those that have pledged support, including access to their facilities, networks and expertise.
Energy and Clean Growth Minister Claire Perry said: “Plastics are not only polluting our waters, they are contributing to climate change and killing sea life.
“The £50 million Framework will help develop options for alternative uses to prevent plastics from ending up in our seas. It also ensures that the UK is at the forefront of encouraging the world to move towards clean growth, tackling the threat from marine plastic and protecting our oceans for future generations.”