The two-week Tube drivers' strike due to start next Monday was called off after a deal was struck through secret negotiations.
Transport for London chief Mike Brown held talks with the RMT union and told leader Bob Crow that a driver at the centre of the dispute will be re-employed.
Brown said the deal had avoided "significant disruption for London".
The RMT was expected to make a statement later today and would only say: "Informal talks have taken place."
The longest ever series of strikes would have caused travel misery for millions next week and again next month. Mayor Boris Johnson said: "I welcome the RMT's decision to call off their industrial action and their recognition that flexing union muscle is unjustified in isolated disciplinary disputes."