LONDON (AP) — London Underground has delayed plans to start a 24-hour subway service on weekends, allowing more time for talks with unions demanding better pay and conditions.

The decision Thursday came as both Underground officials and union representatives reported progress on talks about the new service, which had been set to begin Sept. 12. No new start date was set but Underground officials are hoping for an agreement this fall.

Union members walked off the job twice this summer amid a dispute about how to implement a new 24-hour service on weekends. Unions have been demanding concessions to address work-life balance issues. Transport officials say they've offered a salary increase and bonuses to compensate for the shift changes.

London Mayor Boris Johnson has said he "wasn't fussed" about an exact launch date.