The Southern rail strike causing misery for tens of thousands of commuters was today dramatically called off.
ACAS said the two sides would return to peace talks tomorrow.
Earlier, the RMT union said it would talk to Southern if the company withdrew 'pre-conditions'.
The RMT refused to comment but Southern said no new offer had been made.
Hopes of an immediate return to 'normal service' were dashed when Southern revealed it's strike timetable would still apply tomorrow.
At present, the strike timetable is still in the industry train planning systems for Thursday and Friday. Regrettably, this means tomorrow’s service will be based upon the present strike timetable but we will do our very best to add services in and extend the hours of operation wherever possible.
It added: "For our passengers sake we truly hope these talks will be productive and bring this long running dispute to an end."
Transport secretary Chris Grayling hailed the decision to call off the strike ahead of a resumption of talks.
"This is good news for passengers," he said.
"This strike has inconvenienced people needlessly and I am glad to see RMT sitting round the table as I called for yesterday.
"It's important now to leave the union and the train operator to undertake these necessary talks. I hope they reach a positive conclusion as quickly as possible."
Many Southern passengers reacted with anger to the news that they would suffer a reduced service tomorrow despite the strike being called off.
For the latest updates on which train services will be running on Thursday and Friday, visit Southern's website.