The Magnum Ice Cream Company (TMICC), now the world's largest ice cream producer, began trading on Amsterdam's Euronext as a spin-off from former parent Unilever.Valued at $9.1 billion (€7.8 billion) at its listing, TMICC's Chief Executive Peter ter Kulve will ring the opening bell today in New York while facing challenges including the growing popularity of weight-loss drugs.TMICC aims for 3%-5% organic annual sales growth by evolving its portfolio, but must address governance issues at Ben & Jerry's, with Kulve stating that founders Cohen and Greenfield should hand over to a new generation and that independent board chair Anuradha Mittal no longer meets criteria.