Complex sentence: He oversaw a significant expansion of BAE's Australian operations and established the company's headquarters in Adelaide, South Australia and ran operations from Adelaide until September 2011 when he was tasked to lead BAE Saudi Arabia.
Split into simpler sentences: He oversaw a significant expansion of BAE's Australian operations and established the company's headquarters in Adelaide, South Australia. He ran operations from Adelaide until September 2011 when he was tasked to lead BAE Saudi Arabia.