Liverpool management are delighted with Dan Agger's new contract.
Liverpool have not revealed the exact length of Agger's next contract.
But managing director Ian Ayre said: "Daniel's contribution since joining the club in 2006 has been absolutely fantastic and his loyalty to the team is recognised by the deal he has signed today.
"Daniel always made it clear he wanted to stay at Liverpool and we're delighted that he's committed his future to the club.
"We brought in some very exciting players this summer - some of whom chose Liverpool over clubs in the Champions League.
"But it's equally important to retain your most important players and the fact that Daniel has now followed Luis Suarez, Martin Skrtel and Jonjo Shelvey in signing a new contract is testament to the fact the players believe in what we're trying to achieve here under Brendan Rodgers."