Complex sentence: In 1991, EMIAL purchased the Greek pioneer label Minos (also known as Minos Matsas & Son) and created a new company named Minos EMI, which at the time controlled approximately one third of the Greek market.
Split into simpler sentences: In 1991, EMIAL purchased "Minos Matsas & Son", the company which ran the Greek pioneer label Minos, and created a new company named Minos EMI. At the time, Minos EMI controlled approximately one third of the Greek market.