Manchester United officially announced the signing of Chile youngster Angelo Henriquez, with the striker expressing his happiness at joining the "biggest club in the world".

United completed the capture of the 18-year-old striker after agreeing an undisclosed fee with Universidad de Chile. The club did not announce the length of the contract signed by the teenager.

"Angelo has made a tremendous impact on the game in his short career so far," Ferguson told the club's official website. "His pace is a great asset and he reads the game really well for someone of such a young age.

"We have a proud record of developing young talent and Angelo fits the profile of a United player --skilful, attacking and someone who plays the game with real flair."

Henriquez, who has been given the No 21 shirt, added: "I am thrilled to be joining the biggest club in the world. Manchester United is a great team and has a great manager.

"To be able to be part of that is a huge honor and I can't wait to get started. I hope I can be part of many successful years with United."

Ferguson revealed he had watched the striker for four years, from the age of 14. "We scouted him when he was 14 years old and just monitored him," the manager told Inside United. "When he turned 18, we knew we could take him; it's the first time we can sign them in this country, at 18, and so we were very fortunate the Chile Under-20s were over here.

"They were in tournaments at the Milk Cup (in Northern Ireland) and over in Holland.

"We watched all the games and everyone said: 'You need to bring him in'.

"He's very quick and a good finisher. He's strong, with great shoulders on him for a boy of 18. So hopefully he'll do fine."