Complex sentence: In 2004, Ahold merged Giant and Stop & Shop and eliminated more than 600 positions at Giant's Landover headquarters, creating Stop & Shop/Giant-Landover, which itself is a subsidiary of Netherlands-based Royal Ahold.
Split into simpler sentences: In 2004, Ahold merged Giant and Stop & Shop and eliminated more than 600 positions at Giant's Landover headquarters. Also that year, Giant-Landover merged with sister company Stop & Shop to create Stop & Shop/Giant-Landover, which itself is a subsidiary of Netherlands-based Royal Ahold.