The Daily Star says the cash-rich Turkish outfit were calculating whether to hand Vidic a two-year-deal worth around £150,000-a-week - dwarfing his current wages at United.
It is understood the offer would have included lucrative tax-free bonuses that guaranteed Vidic a bumper pay-day before he retires.
But his hopes of joining Galatasaray have been dashed after Mancini performed a u-turn and changed his mind.
The Italian explained: "Every manager would want a player as experienced as Vidic on their team.
"He is the type of player who can really make a difference, however, I need a player who can play Champions League football.
"It doesn't matter how good he is I need a player ahead for the Champions League urgently and as a result Vidic isn't in our plans."
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