Complex sentence: In 1988, Yetnikoff was the chief architect of the deal to sell CBS Records to The Sony Corporation based on his decades-old relationship with the corporation, which marked the first time that a Japanese firm bought a major American music company.
Split into simpler sentences: In 1988, Yetnikoff was the chief architect of CBS Records' sale to the Sony Corporation based on his decades-old relationship with Sony. The sale marked the first time that a Japanese firm bought a major American music company.