Complex sentence: In 1989, the company that controlled the magazine and its related projects (part of "21st Century Communications") was the subject of a hostile takeover, and in 1991 it was sold outright to another company, "J2 Communications".
Split into simpler sentences: In 1989, the company that controlled the magazine and its related projects (which was part of "Twenty First Century Communications") was the subject of a hostile takeover. In 1991 it was sold outright to another company, "J2 Communications".