London Underground is proposing a long-term pay deal lasting up to five years and covering all of its 12,000 staff.
Talks have begun between management and union leaders representing drivers, signallers, station staff and administrative employees, the BBC reports.
London Underground said the stability of a long-term agreement would be in the best interests of Tube staff and passengers.
However, Tube union RMT, which has 6,500 members, said it would not commit to any deal longer than a year as it would leave the union a “hostage to economic fortune”.
Strained industrial relations between London Underground and the unions have led to two strikes since the beginning of the year.