In the QUODD Global Corporate Actions API we offer the GetMergers endpoint which returns merger events for a given identifier and date range. QUODD defines merger events as a merger of equals, where Company A and Company B combine to make a new, separate Company C. Company A and Company B cease to exist.
Many merger examples are in reality acquisitions, in which one company acquires another and there is a clear distinction in which company is the ‘surviving’ company. The event you are looking for might be in the GetTakeovers endpoint.