Crespo had a work-out at Stamford Bridge on Tuesday

The capture of the Argentine was officially announced at half-time during Chelsea's Champions League game against MSK Zilina on Tuesday.

Crespo becomes Chelsea's 11th signing of the summer and brings the total spent on transfer fees since the takeover by Russian billionnaire Roman Abramovich to nearly �95m.

Centre-forward Crespo, who passed a medical earlier on Tuesday, will be hoping international clearance comes through in time to make his debut against Blackburn this weekend.

I've come here to win things, not just to participate - we will do everything we can to win things Hernan Crespo

He could play in that game alongside Adrian Mutu, who at �15.8m from Parma was Claudio Ranieri's other big-name signing up front.

Damien Duff, Juan Sebastian Veron, Geremi, Wayne Bridge, Joe Cole, Glen Johnson, Alexei Smertin, Marco Ambrosio and Jurgen Macho were the other captures made by cash-rich Chelsea this close-season.

Chelsea's John Terry greeted the signing of Crespo enthusiastically.

CHELSEA CASH SIGNINGS Glen Johnson: �6m Wayne Bridge: �7m Damien Duff: �17m Geremi: �7m Juan Sebastian Veron: �15m Joe Cole: �6.6m Adrian Mutu �15.8m Alexei Smertin: �3.45m Hernan Crespo: �16.8m Total to date: �94.65m

"The manager's made great signings and players like Juan Sebastian Veron and Crespo can only improve the other players," said Terry.

"We've already got fantastic guys like Eidur Gudjohnsen and Jimmy Floyd Hasselbaink - and the players think the signings are good competition.

"It's exciting times here and good for everybody."

Crespo told Chelsea TV: "I am very happy to be at Chelsea.

"I've come here to win things, not just to participate - we will do everything we can to win things."