London Underground drivers will not be joining two fresh strikes later this month over the night Tube dispute.
Further talks will be held between the drivers' union Aslef and managers in a bid to resolve the long-running row.
LU denied speculation it was delaying the September 12 start date for its new all-night Tube service, insisting it was "operationally ready", although repeating the service would not be launched "at any cost".
Members of three unions are due to stage two 24-hour walkouts from the evening of August 25 and 27 following two stoppages in the past month.
Talks were held today at the conciliation service Acas in a bid to break the deadlock.
Members of the RMT, TSSA and Unite unions are due to take part in the new strikes in the run-up to the August Bank Holiday.
Aslef held off making any announcement on strikes until today's resumed talks, and decided not to take part in the new stoppages.
New demands by unions would cost £1.4 billion and lead to "significant" fare rises, the company has claimed.
LU said no responsible management could agree to the demands being made by union leaders.
A statement said the cost of what unions were asking for would be about £1.4 billion to 2023/24, increasing fares by 6.5% or scaling back modernisation plans.
Chief operating officer Steve Griffiths said: "Having previously argued that it was all about work-life balance, certain unions have now made a whole series of unaffordable demands for more pay, shorter working hours and the reversal of the modernisation of the Tube."
Meanwhile, industrial action is already hitting Tube services ahead of the two fresh strikes, the RMT claimed.
Officials said delays on the District Line today were caused by a work to rule, warning that the impact will escalate.