## Facts

- DuPont and Imperial Chemical Industries Ltd. (ICI) entered cross-licensing and territorial arrangements for nylon technology, with ICI holding rights to exploit certain nylon patents in the United Kingdom and parts of the Commonwealth.
- ICI and Courtaulds formed British Nylon Spinners Ltd. (BNS) to manufacture nylon yarn in the UK; BNS operated under an exclusive sublicence tied to ICI’s UK patent position.
- The U.S. government brought antitrust proceedings against DuPont and ICI, challenging territorial and market-division arrangements involving nylon.
- During restructuring associated with the U.S. proceedings, DuPont assigned its British nylon patents to ICI, and ICI agreed to grant BNS an exclusive direct licence under the relevant UK patents.
- A U.S. federal decree later ordered relief aimed at preventing continuation of anti-competitive arrangements, including directions that would inhibit ICI from enforcing its British patents in ways viewed as perpetuating the restraint.
- BNS, not a party to the U.S. case and not subject to U.S. jurisdiction, sued ICI in England seeking specific performance of the promise to grant the exclusive licence and related injunctive relief.
- ICI argued that compliance with the U.S. decree (and considerations of comity) excused or prevented performance of its English contractual obligation to BNS.

## Issues

1. Whether ICI was contractually bound under English law to grant BNS the promised exclusive licence under the UK nylon patents, and whether specific performance was an appropriate remedy.
2. Whether the U.S. antitrust decree excused, prevented, or legally displaced ICI’s performance of its English contractual obligations to BNS.
3. Whether principles of international comity required an English court to withhold enforcement of the contract because performance could conflict with a foreign public-law order.

## Decision

- The court held ICI remained bound by its undertaking to grant BNS an exclusive licence under the relevant UK patents.
- The court ordered specific performance compelling ICI to grant the licence and granted associated injunctive relief restraining conduct inconsistent with that obligation.
- The court rejected the U.S. decree as a defence to performance under English contract law and declined to treat comity as requiring non-enforcement of BNS’s contractual rights.

## Legal Principles

- A foreign public-law decree does not, by its own force, cancel or vary contractual rights governed by English law concerning property and obligations situated in England.
- Comity entails respect for foreign courts but does not require an English court to subordinate domestic private rights to a foreign regulatory judgment, particularly where the claimant was not a party to the foreign proceedings and is outside that foreign court’s jurisdiction.
- Potential exposure to foreign sanctions for performing an English contract does not, without more, make performance legally impossible or discharge the contract under English law; the promisor remains responsible for the conflict it faces and must seek relief in the foreign forum if needed.
- A foreign judgment generally binds only parties (and privies) to the foreign proceedings; absent participation or privity, it does not create estoppel against a non-party’s English contractual rights.

## Conclusion

The court enforced an English promise to grant an exclusive UK patent licence by ordering specific performance, holding that a U.S. antitrust decree and comity concerns did not extinguish or excuse performance of contractual rights governed by English law and held by a non-party to the U.S. proceedings.


British Nylon Spinners, Ltd. v. Imperial Chem. Indus., Ltd., [1955] 1 Ch. 37 (Ch. 1955)