Move could be announced before World Cup...
Chelsea and both Manchester City and United have been linked with the Ivory Coast international recently but according to the agent, a deal has already been signed.
Arsenal had made their interest known in Toure, but he reportedly turned the Guners down.
"If everything goes well, Yaya will go to England," Dimitri Seluk told Ona FM.
"But we can't talk about definite clubs. We already have a closed deal, and all will be resolved before the World Cup."
Toure fell out of favour at Barcelona last season after only making a handful of appearances towards the end of the campaign but that has not stopped the Catalan giants from demanding almost £30 million for the midfielder.
Seluk added: "It seems to me too much money. His club have shown they want him to leave, it's not normal that they're asking for this amount.
"If [Barca president Joan Laporta] likes Toure so much, he could have explained why he didn't play so much.
"This year we haven't spoken to him even one time, and if he leaves it's because that was lacking."
If Yaya makes the switch to Manchester City this summer, he will have the opportunity to team up with his brother Kolo, who captains the side.