Britain will no longer participate in the proposed Unified Patent Court (UPC) regime, for the settlement of disputes relating to European patents and European patents with unitary effect.
The move will mean an imminent overhaul of the UPC set-up since Britain was to host a central division of the body, with responsibility for cases in relation to human necessities (including pharmaceuticals), chemistry and metallurgy.
Italy or the Netherlands is likely to step in and run the unit instead.
The Unified Patent Court is a court common to 25 Member States currently signed up to the Agreement, which Britain ratified in April 2018.
Participation in the UPC means accepting EU laws and decisions of the Court of Justice of the European Union (CJEU).
The decision to pull out is spelled out in a Downing Street position paper The Future Relationship with the EU.
The UPC is also under constitutional challenge in the German courts with a decision expected this year.
Britain is still a contracting state to the European Patent Convention (EPC), which oversees European patent applications.
The EPC is a separate body from the European Union and with upwards of 40 contracting states.
These include all the EU countries but also many non-EU ones.