Complex sentence: Another development project, Centum City, has been ongoing since early 2000, and has become a new landmark in Busan, with its BEXCO (Busan Exhibition and Convention Center) becoming a popular venue for international conventions and exhibitions.
Split into simpler sentences: Another development project, Centum City, has been ongoing since early 2000 and is now a major feature of Busan. Its BEXCO (Busan Exhibition and Convention Center) has become a popular venue for international conventions and exhibitions.