Chelsea sign French teenager Amougou from Saint-Etienne

French teenager Mathis Amougou on Tuesday signed for Chelsea from Saint-Etienne in a deal reported to be worth 15 million euros ($15.5m).

The Premier League club confirmed the 19-year-old midfielder has penned an eight-year contract and will begin training in the coming days.

"I'm very happy. It's an honour for me to sign for such a big club like Chelsea," Amougou said. 

"They believe in young players and the process they have in place to develop us is fantastic."

Amougou made his debut for Saint-Etienne at the start of last season and featured in Ligue 2 as the club secured promotion to the French top flight.

He established himself as a regular starter at the beginning of the current campaign and made 17 appearances in Ligue 1.

Amougou had five months left on his contract with Saint-Etienne but failed to agree terms for an extension with the relegation-threatened Ligue 1 side.

Amougou has played for France at youth level and received the Bronze Ball for his performances at the 2023 Under-17 World Cup, earning a call-up to the Under-20 squad earlier this season.

Chelsea are fourth in the Premier League, 13 points behind leaders Liverpool.