Complex sentence: Both companies had established main production centres at Elstree, Hertfordshire and Teddington, Middlesex respectively but despite conflicts over contract applications and rivalry over the corporate acronym, the costs of creating separate facilities in the Midlands led to a decision to join forces.
Split into simpler sentences: Both companies had established main production centres at Elstree, Hertfordshire and Teddington, Middlesex respectively but despite conflicts over contract applications and rivalry over the corporate acronym. The costs of creating separate facilities in the Midlands led to a decision to join forces.