Complex sentence: The creation of the joint venture was concurrent with the creation of Alcatel Alenia Space, formed by the merger of two other Alcatel and Finmeccanica space businesses (Alcatel Space and Alenia Spazio respectively).
Split into simpler sentences: The creation of the company was concurrent with the creation of Alcatel Alenia Space. This too was a merger of Alcatel and Finmeccanica businesses (Alcatel Space and Alenia Spazio respectively).