Complex sentence: It marked its centenary in 1998, but ran into financial troubles in 2003, when it was bought out by Peter Mayer, though it continues to publish under the name of Duckworth.
Split into simpler sentences: It marked its centenary in 1998, but ran into financial troubles in 2003. It was then bought out by Peter Mayer, though it continues to publish under the name of Duckworth.