Complex sentence: After this, the "Regent Rainbow" was chartered to Thomson Cruises and its name was changed to "The Emerald" and in 2001, it was bought by Louis Cruise Lines, but continued to be chartered to Thomson Cruises.
Split into simpler sentences: After this, the "Regent Rainbow" was chartered to Thomson Cruises and its name was changed to "The Emerald". In 2001, it was bought by Louis Cruise Lines, but continued to be chartered to Thomson Cruises.