Final answer:
In the case of Energy Transfer Partners L.P. v. Enterprise Products Partners L.P., the legal issue was whether a partnership was formed between ETP and Enterprise without a board-of-directors approved agreement.
Step-by-step explanation:
The issue before the Supreme Court of Texas in the case of Energy Transfer Partners L.P. v. Enterprise Products Partners L.P. was whether a partnership between ETP (Energy Transfer Partners) and Enterprise was formed without a board-of-directors approved agreement. This case addresses complex issues of partnership formation and the obligations that may arise incidentally during the course of business negotiations and preliminary agreements in the energy sector. The significance of the case lies in the intricate interpretation of partnership laws and their application in the context of the energy industry.