De facto agents in joint control
A contractual arrangement has three parties: A has 50% of the voting rights and B and C each have 25%. The contractual arrangement between A, B and C specifies that at least 75% of the voting rights are required to make decisions about the relevant activities of the arrangement.
Analysis
There is neither control nor joint control, because more than one combination of parties can reach 75% and therefore direct the relevant activities.
Variation If the facts and circumstances changed, such that C was deemed to be a de facto agent of B, then A and B would have joint control, because effectively B would direct 50% (in combination with C’s 25%) and A would need B to agree to direct the relevant activities.