The latest development follows a series of meetings between Thaksin's right-hand man Pairoj Piempongsant and Ronaldinho's brother and chief negotiator Roberto De Assis.
City's extravagant ambition has been laughed off around the football world - but that would be to underestimate the determination of their Thai owner and his new executive chairman, Garry Cook.
Talks have opened with the player's major sponsor Nike, along with other possible investors who may help finance the exorbitant wage demands.
Ronaldinho, it is claimed in Spain, wants around £200,000-a-week to leave Barcelona. Such a deal would make him the highest-paid player in England - dwarfing the £135,000-a-week paid by Chelsea to England captain John Terry.
It is no coincidence that Cook is joining City from Nike, where he was a brand president and with whom Ronaldinho has a long-term contract.
City have been given clearance from Barcelona to open detailed talks. A pay-as-you-play deal could be thrashed out with club and player, with performance-related bonuses for a forward who has scored an impressive 70 goals in 145 La Liga games.
A source in Spain said: "Ronaldinho is showing a growing interest in going to England and while there is still much negotiating ahead, it is possible. Also in City's favour is this: Who else can afford him?"