Juan Sebastian Veron has completed his £15m move to Chelsea from Manchester United.
The Argentina international passed a medical and agreed personal terms before signing a four-year deal at Stamford Bridge late on Wednesday.
£2.5m of the transfer fee is dependent on Chelsea's results over the next four seasons.
The deal, coming only hours after the £6.6m arrival of Joe Cole, takes Chelsea's summer spending beyond the £58m mark.
Veron and Cole will be unveiled at a 1530 BST media conference on Thursday - and are both available for the Champions League
qualifier against Slovakia's Zilina next week.
Chief executive Trevor Birch said: "We have bought a young Englishman
with huge potential and a great champion who can lead us on to better things.
"It has been a marvellous day for Chelsea."
Veron, who cost Man Utd £28.1m two years ago, said: "I can do a job in English football - and in London that will be
Explaining the decision to let the Argentine leave Old Trafford, Manchester United boss Sir Alex Ferguson told MUTV: "It's always difficult letting good players go.
"But we are very, very well off in the midfield and the overall package made it too interesting for us not to take it.
CHELSEA'S SUMMER SPENDING
Juan Sebastian Veron
Man Utd £15m
Real Madrid £7m
West Ham £6.6m
West Ham £6m
"We're trying to be sensible in a market that's had its fingers burnt throughout Europe.
"He was on a massive salary and it's worth a lot of money to us.
"We had a collection of central midfield players who made my life difficult enough as it is so when an offer came in for Seba we decided to take it."
Veron's agent Fernando Hidalgo said: "He is ready to do the best he can with this new opportunity at Chelsea - but it was not his intention to leave the club."
Veron said: "Ferguson trusted me when I first arrived. But later on it seemed we didn't understand each other as well. There were times when I felt he preferred some of my team-mates."