If no agreement is reached City face the prospect of the case being handed to a panel for a non-negotiable decision.
Neither the club nor UEFA would comment but it is understood the City have been negotiating forcefully for a significant reduction in that sanction but have been struggling to make progress.
No club is expected to be excluded from the Champions League for breaching the spending limits, the maximum possible sanction - UEFA president Michel Platini said last month he does not envisage that to happen.
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