The Argentina international has joined the Magpies from Deportivo La Coruna for an undisclosed fee although the club have revealed it is more than the £9million they paid Leeds for Jonathan Woodgate.

Coloccini, who has signed a five-year contract at St James' Park, is the club's third major close season signing after his Argentina team-mate Jonas Gutierrez moved from Real Mallorca and Danny Guthrie signed from Liverpool.

Keegan is confident that the 26-year-old will be able to help shore up a Newcastle defence which leaked 65 goals in the Barclays Premier League last season.

"I am delighted that the deal is now done - Fabricio has got tremendous experience and is a full international with Argentina, that tells you he is a player of the very highest calibre," he said.

"He does not know the Premier League but he knows world football and has played in one of the top leagues, La Liga for six years now.

"He's a very athletic player, he played every minute in the league for his club last season, and he's also very versatile.

"He is a centre-back but can play anywhere across the back four and also in midfield - he gives us massive options."

Coloccini began his career at Boca Juniors in 1998 before moving to AC Milan the following season although he made just a solitary appearance at the San Siro.

The Rossoneri loaned out Coloccini to San Lorenzo, Alaves, Atletico Madrid and Villarreal before he moved to Deportivo in 2004.

He has won 27 caps for Argentina and was part of the Argentina Under-20 side that won the 2001 FIFA World Youth Championship as well as the 2004 Olympic gold medal-winning team and appeared in the 2006 World Cup.

Coloccini believes he has all the attributes to be a success in the Premier League and is keen to impress the club's supporters after hearing positive things from Gutierrez.

He said: "Jonas has only been here a little while but he told me that we have very good supporters and an incredible stadium.

"I'm very excited to be here and it is a dream to play for such a big club in the Premier League. Playing at St James' Park, in front of those fans, is something I cannot wait to do.

"I have known about Newcastle's interest for a while and I wanted to sign because it is a club I know all about from my time watching English football in Spain and Argentina.

"I'm a defender who will always try my best for the team - I think I am a good technical player and I will be suited to the speed and physical side of the game in England.

"I am also still fit because I was doing pre-season training with Deportivo and I can't wait to get started."

Keegan also revealed that Coloccini's hair cut, which is reminiscent of the infamous perm Keegan sported during his playing days, has been a talking point among the players.

He added on www.nufc.co.uk: "A few of the lads have already said that me and Terry McDermott want to revive the perm, but as long as this lad can play we are not bothered what his hair is like!"