Amir Khan will fight three-weight world champion Marco Antonio Barrera on March 14. The Olympic silver medallist has confirmed the date of the fight but a venue has not been chosen yet. Promoter Frank Warren said: "This is a huge step up for Amir who had some serious thoughts about it. The discussions over the fight finished at 4am this morning. "It's a big fight for Amir who has been champing at the bit. This is the right fight for Amir at this stage of his career. "I believe it will bring out the best in him. This puts him well and truly on the world stage." Barrera has won 64 of his 71 professional bouts and he will provide the toughest challenge of Khan's career so far.