Complex sentence: Although final assembly was carried out by Santa Bárbara Sistemas, the production of the AMX-30E also included various other companies in the country and total production within Spain amounted to as much as 65% of the tank.
Split into simpler sentences: Although final assembly was carried out by Santa Bárbara Sistemas, the production of the AMX-30E also included other companies in the country. Total production within Spain amounted to as much as 65% of the tank.