Sabre Corporation's Board of Directors adopted a limited-duration shareholder rights plan, effective immediately and expiring on February 28, 2027. The plan was enacted in response to Constellation Software Inc. accumulating a 9.7% economic position in Sabre between April and November 2025, comprising 4.7% beneficial ownership and 5% via derivative instruments. Constellation Software had privately informed Sabre of its stake in early January 2026, requested a board seat, and delivered a nomination notice on January 23, 2026. Negotiations for a strategic governance agreement, including a board seat for Constellation's Vela Software CEO, abruptly broke down on February 26, 2026, despite nearing completion. The Rights Plan is triggered if any person or group acquires 15% or more (or 20% for certain passive investors) of Sabre's outstanding common stock. Upon triggering, all non-triggering rights holders can acquire common stock at a 50% discount, or Sabre may exchange each right for one common share. Existing holders above the triggering percentage, like Constellation, can maintain their stake but cannot acquire additional shares without triggering the plan. The plan does not include "dead-hand," "slow-hand," or "no-hand" features, allowing a future board to redeem the rights. Sabre remains open to resuming discussions with Constellation regarding a negotiated agreement on acceptable terms.