Complex sentence: Carillion was created in July 1999 by a demerger from Tarmac, which was founded in 1903; the new company included the former Tarmac Construction contracting business and Tarmac Professional Services.
Split into simpler sentences: Carillion was created in July 1999 by a demerger from Tarmac, which was founded in 1903. The new company included the former Tarmac Construction contracting business and Tarmac Professional Services.