The 19-year-old featured 16 times on loan for the Spanish side last season after joining on a short-term loan in January, with new manager Gus Poyet keen to retain the services of the attacking midfielder for another season.
He had been linked with a move to Turkish giants Fenerbache with his future under incoming boss Antonio Conte unclear, yet they have been pipped to the youngster’s signature by Spanish club Betis.
A statement on Chelsea’s official website read “Charly Musonda will continue his development in La Liga with his loan to Real Betis extended to cover the 2016/17 season.”
Musonda, who has a contract with the Blues until 2019, has been at Stamford Bridge since joining from Anderlecht in June 2012, but is yet to make a first-team appearance for the Blues.
The Belgium under-21 international helped his new side to tenth in La Liga last season and told www.realbetisbalompie.es of his joy at returning to the Benito Villamarin stadium.
“I am very happy. This year was very good and I hope the next will be. For my progression I hope to play well here and learn.
“Playing in a Primera Division team is very good and Betis is the perfect club.”