Complex sentence: As of June 2014,84 million Xbox 360 consoles have been sold worldwide, making it the sixth-highest-selling video game console in history, and the highest-selling console made by an American company.
Split into simpler sentences: As of June 2014,84 million Xbox 360 consoles have been sold worldwide, making it the sixth-highest-selling video game console in history. The Xbox 360 is also the highest-selling console made by an American company.