London Underground management and unions have failed to agree on plans to run subways around the clock, further delaying a service that was supposed to start last month.

All-night service on weekends had been due to begin Sept. 12. But after two disruptive strikes this summer the launch was delayed so that management and unions could hold talks on pay and conditions.

Transport officials say they've offered workers a salary increase and bonuses to compensate for shift changes.

Unions have been demanding concessions to address work-life balance issues and accuse London Underground of rejecting all their proposals.

The mediation service ACAS, which hosted the negotiations, said Wednesday that "talks adjourned today and the parties are reflecting upon their positions. There are no further talks planned at this current time."