Everton have been forced to wait to finalise the signature of Chelsea striker Romelu Lukaku.
Manchester United legend Paul Scholes says the current squad at Old Trafford is unbalanced.
The Spain international was at the Nou Camp this afternoon to put pen-to-paper on the deal which ties him to the club until June 30, 2016.
Xavi follows in the footsteps of club captain Carles Puyol who signed his new contract committing him to Barca until the same date last week.
Barca announced last month they had agreed new deals with the long-serving duo as well as with star forward Lionel Messi, whose new contract will keep him at the Nou Camp until 2018.
Xavi, who turned 33 last week, came up through the youth ranks at Barca and has played a key role in their unprecedented success of recent years.
During his time at the club he has won a host of trophies, including six Primera Division titles, three Champions Leagues, two FIFA Club World Cups and two Copa del Rey crowns.