The highly-rated 21-year-old made his first-team debut for Barca in November 2011 before going on to make 22 appearances last season, playing in the league, Copa del Rey and Champions League.
This season Tello has made 16 appearances in all competitions for Barca, having represented Spain at this summer's Olympics.
A Barcelona statement read: "Barcelona announce they have reached an agreement with the player Cristian Tello to extend his contract until June 30, 2016. His buy-out clause has been set at 10 million euros.
"The player will sign his contract on Monday, December 17, in the Barcelona offices."
may well get slated by other United fans for this, but out of the three contenders, I'd far prefer Liverpool to win the title. Yes some elements of their fanbase can be a bit OTT, yes they're our biggest rivals and yes it will make our poor season feel even more like the end of an era (Fergie's gone, Liverpool are back on top). However I just have to applaud Brendan Rodgers and the way he's turned Liverpool around in just a couple of seasons. It...
ooray! We are all excited now, we beat a very mediocre team! With all due respect to WHU supporters, not winning that game shouldn't even be a consideration. This is the problem, there is no winning mentality at the Emirates - we're all congratulating ourselves beating a team that we have a winning record against.
s this meant to be an aspiration for United supporters? Moyes mediocrity strikes again. I see the Bayern boys don't want to sign for him, and his reputation amongst the senior European coaches make other key signings unlikely.