Striker Costa signs five-year deal at Chelsea

"I am very happy to sign for Chelsea. Everybody knows it is a big club in a very competitive league, and I am very excited to get started in England with a fantastic coach and team mates," Costa, 25, was quoted as saying on the club's website.

"I know the high quality of the squad I am joining.

"I would like to thank everybody at Atletico who made me into the player I am. It was an incredible time for me, but now I am starting a new adventure and I hope to win many trophies with Chelsea."

Powerful and direct, the Brazilian-born striker built a strong reputation in Spain as a fine finisher, scoring 64 goals in 134 appearances for Atletico, and helping them to the Spanish title last season and the Champions League final.

(Reporting By Tony Goodson; Editing by Rex Gowar)