Complex sentence: In the early 90s, Ubisoft initiated its in-house game development program which led to the 1994 opening of a studio in Montreuil, France, which later became their administrative and commercial head office, even if the company continues to register their headquarters in Rennes.
Split into simpler sentences: In the early 90s, Ubisoft initiated its in-house game development program, which led to the 1994 opening of a studio in Montreuil, France. It later became their administrative and commercial head office, even as the company continues to register its headquarters in Rennes.