Complex sentence: In September, ARS would be bought out by Infinity, which effectively returned the station under Infinity ownership, which merged with CBS' radio division the following year while retaining the "Infinity" name (Infinity would be renamed CBS Radio in December 2005).
Split into simpler sentences: In September, ARS would be bought out by Infinity, which effectively returned the station under Infinity ownership. Infinity merged with CBS' radio division the following year while retaining the "Infinity" name (Infinity would be renamed CBS Radio in December 2005).