Complex sentence: Since its launch, the model has been a primary driver of the twinjet's sales past the rival A330/340 series, its direct competitors have included the Airbus A340-600 and the A350-1000.
Split into simpler sentences: Since its launch, the model has been a primary driver of the twinjet's sales past the rival A330/340 series. Its direct competitors have included the Airbus A340-600 and the A350-1000.