The chief executive of the parent company of Southern Railway has invited the RMT union for face-to-face talks in a bid to settle a long-running dispute over the role of conductors.
Charles Horton of Govia Thameslink Railway (GTR) wrote to Mick Cash, general secretary of the Rail, Maritime and Transport union (RMT), saying his negotiating team was willing to meet next week "in a spirit of open and positive dialogue to explore the areas of difference between us with a view to resolving the dispute in the interests of our customers and employees".
The move followed a deal reached with the drivers' union Aslef over driver-only trains, which is being put to a ballot of members over the next few weeks.
Mr Horton said talks with the RMT should be conducted without the threat of further industrial action hanging over them.
He said: "We are pleased to have reached a deal with the Aslef leadership.
"They were prepared to come to the table, with passengers liberated of any threat of strike action.
"Both parties arrived ready to listen, have an open mind and ready to do a deal.
"We would call on the RMT to follow that same consensual spirit and leadership and come to the table with the courage, confidence and conviction to settle their dispute for the benefit of passengers, the regional economy, their members and our employees."
An RMT spokesman said: "We can confirm that we have had a formal offer of talks from GTR.
"That offer will be considered by RMT's executive later today. The union will be making no further comment until the executive has met."
The RMT has staged a series of strikes in protest at changes to the role of conductors to on-board supervisors, warning of the impact on safety.
Prime Minister Theresa May's spokesman said talks needed to happen to end the "untold misery" being caused by the dispute.
Asked if Mrs May had a message for the RMT, the spokesman told a regular Westminster briefing: "The message would be a simple one, to get back round the table with GTR and bring an end to these strikes which are causing untold misery for commuters."