Who is Rocco Basilico and why the Ray-Ban heir has rejected a $3.9 billion buyout offer for stake in family firm Delfin?

A family dispute at Delfin has escalated after Rocco Basilico turned down a $3.9 billion buyout offer from Leonardo Maria del Vecchio for his 12.5% stake. Basilico reportedly wants $4.8 billion, while three shareholders are seeking to ease rules governing board changes.