## Facts

- Two competing insurance and financial-services groups used “SUN LIFE” formative names in U.S. commerce over many decades.
- Sun Life Assurance Company of Canada and its U.S. affiliate (defendants) claimed long prior use of the SUN LIFE mark and asserted senior trademark rights in the United States.
- SunAmerica Corporation and its related insurer (plaintiffs), successors to entities using SUN LIFE-formative names, continued U.S. use, sometimes with geographic modifiers.
- In 1989, SunAmerica sued under the Lanham Act and related theories, alleging defendants’ use of “SUN LIFE” and “SUN LIFE (U.S.)” without “of Canada” caused confusion.
- Defendants counterclaimed for trademark infringement and sought to bar SunAmerica from using any SUN LIFE mark.
- After a bench trial with extensive historical evidence and survey evidence, the court issued findings of fact and conclusions of law.

## Issues

1. Whether defendants were the senior user of the SUN LIFE mark in U.S. commerce with enforceable trademark rights.
2. Whether the parties’ concurrent SUN LIFE usage created a likelihood of consumer confusion.
3. Whether defendants’ long-term tolerance of plaintiffs’ use constituted acquiescence that equitably barred defendants’ counterclaim for infringement.
4. Whether a finding of “inevitable confusion” could overcome acquiescence and permit injunctive relief against the junior user.

## Decision

- The court found defendants were the senior user of the SUN LIFE marks and held they possessed enforceable rights.
- The court found a likelihood of confusion between the parties’ marks and names in the U.S. marketplace.
- The court held defendants had acquiesced in plaintiffs’ use over time, which would ordinarily bar defendants’ infringement counterclaim.
- The court nevertheless found confusion between the parties’ names and marks was inevitable and held this inevitability revived defendants’ ability to enforce their senior rights despite acquiescence.
- The court granted defendants a permanent injunction prohibiting plaintiffs’ continued use of SUN LIFE marks.

## Legal Principles

- Trademark priority generally rests with the senior user, who may enforce protectable rights against a junior user when a likelihood of confusion is shown.
- Likelihood of confusion may be established by evaluating mark similarity, relatedness of services, overlap in channels and markets, and consumer evidence such as surveys.
- Acquiescence (equitable estoppel by knowing tolerance or implied consent) can bar a senior user from later seeking injunctive relief against a junior user.
- A court may treat “inevitable confusion” as a public-interest exception that permits enforcement by a senior user even where acquiescence would otherwise preclude relief.
- When granting injunctive relief in a long-running concurrent-use dispute, equitable considerations affect both entitlement to relief and the scope of any injunction.

## Conclusion

The court concluded that although defendants’ prolonged tolerance of plaintiffs’ SUN LIFE use constituted acquiescence, the parties’ direct competition and naming overlap made confusion inevitable; that inevitability allowed enforcement of defendants’ senior rights and supported a permanent injunction barring plaintiffs’ continued use of SUN LIFE marks.


SunAmerica Corp. v. Sun Life Assurance Co. of Can., 890 F. Supp. 1559 (N.D. Ga. 1994)