[en]Based on CEO pay monitoring in French listed companies, this study first searches for the relevant metric of controlling shareholdings. The equity share held by the largest shareholder directly or indirectly represented on the board of directors, plus shareholders acting in concert with it, is associated with effective control – while other blockholders, whether or not they sit on the board, and deviations from “one share-one vote”, do not enhance monitoring. Second, a panel threshold regression (PTR) model allows to identify various regimes of control. Four regimes are found in the degree of control. A threshold at about 10% of equity separates out “non-controlled” from effectively-controlled firms; three regimes of effective control are then identified. They are termed as “influential” (from about 10% to one-third of equity), “dominant” (up to about 45%), and “majority” (over 45%) controls. Specifically, CEO pay packages provide evidence of entrenchment for dominant controlling shareholders. Then, this study introduces seniority of control as a second criterion for effective control. The PTR model allows to distinguish two regimes termed as “new” and “long-term” control: new controlling shareholders need about six to eight years to reduce asymmetries of information and no longer rely on alternative monitoring devices. The study lastly discusses the relevance of discontinuous threshold effects compared to some continuous specifications found in the literature on ownership[/en]