Complex sentence: Cathay Pacific is a founding member of the Oneworld alliance, with its subsidiary, Dragonair, as an affiliate member although Cathay Pacific is part of Oneworld it own's Air China which is in the competing Star Alliance.
Split into simpler sentences: Cathay Pacific is a founding member of the Oneworld alliance, with its subsidiary, Dragonair, as an affiliate member. Although Cathay Pacific is part of Oneworld it own's Air China which is in the competing Star Alliance.