Javier Mascherano has signed a four-year contract with Liverpool.
Javier Mascherano moved to Anfield from West Ham in early 2007
The 23-year-old, whose contract was owned by the Media Sports Investments consortium, moved to Anfield on loan from West Ham just over a year ago.
The Argentine midfielder was able to sign for Liverpool outside the transfer window because he does not belong to another club.
"I am very, very happy and now I can concentrate just on playing football," Mascherano told Liverpoolfc.tv.
"I said all along that I wanted to stay at Liverpool and now that I have signed I can say this is the best and the biggest moment in my career so far.
"From the first day I arrived at Liverpool the feeling was good and I knew this was where I wanted to play my football.
"It's good news for me and my family that everything is sorted and I know where my future is going to be. I just want to do my best for the fans and the people of the club.
"I am at a top side and I know I can win titles here. That's the big thing for me. I want to be at a club where we can win trophies and have success."