Network Rail will make a fresh attempt to break a deadlocked dispute with its maintenance workers today.
The firm will outline how it intends to "simplify" planned changes during talks with the Rail Maritime and Transport (RMT) union.
Network Rail (NR) chief executive Iain Coucher said in a letter to RMT leader Bob Crow he was "very concerned" about the lack of progress made during a series of talks in recent weeks.
The union had threatened strikes in protest at plans to cut 1,500 maintenance jobs but the action was called off after a legal challenge by NR.
Mr Coucher said progress had been "difficult", partly due to the complexity of proposed changes, as well as the many different terms and conditions of workers involved in the row.
Some proposals will now be withdrawn, and NR said it was continuing to provide assurances of no compulsory redundancies this year.
"We have listened to the views of our people and believe that these simplified proposals represent a lower level of change than we wanted."
Mr Crow said the offer was by "no means" a finalised package, adding: "We are pleased that Network Rail have moved away from their aggressive and confrontational approach.
"Any detailed proposals aimed at resolving the dispute will be considered in full."
The two sides are also involved in a separate dispute over planned changes to signal workers' conditions.