Paul Coulson’s initial offer when Ardagh’s negotiations opened with its bondholders in March was that he and his co-shareholders would relinquish ownership of the international packaging group but retain an 80 per cent interest in the unit that, in turn, owns 76 per cent of its listed metal can business. Ardagh Metal Packaging (AMP) is the jewel in the crown of the Coulson-founded group. It is more profitable, better capitalised and faster-growing than the bulkier, struggling glass bottle division. As its share price hovered around $4 in New York this Monday, AMP had a market capitalisation of $2.4 billion (€2.1…