Complex sentence: The first commercial plant was built by their subsidiary, Amoco Chemicals Corp., beginning production in 1958 in Joliet, Ill. AMOCO become the world's largest manufacturer of terephthalic acid, and was later acquired by BP.
Split into simpler sentences: The first commercial plant was built by their subsidiary, Amoco Chemicals Corp. in Joliet, Illinois. AMOCO went on to become the world's largest manufacturer of terephthalic acid, and was later acquired by BP.