(a) Reportable event. A reportable event occurs for a plan when a member of the plan's controlled group -
(1) Is involved in any transaction to implement its complete liquidation (including liquidation into another controlled group member);
(2) Institutes or has instituted against it a proceeding to be dissolved or is dissolved, whichever occurs first; or
(3) Liquidates in a case under the Bankruptcy Code, or under any similar law.
(b) Waivers - (1) De minimis 10-percent segment. Notice under this section is waived if the person or persons that liquidate do not include any contributing sponsor of the plan and represent a de minimis 10-percent segment of the plan's controlled group for the most recent fiscal year(s) ending on or before the date the reportable event occurs.
(2) Foreign entity. Notice under this section is waived if each person that liquidates is a foreign entity other than a foreign parent.