The Progressive Unionist Party and Sinn Fein in Londonderry have said they will work together on community issues.
The PUP and Sinn Fein in Derry said they will work on community issues
In a statement the unionist and republican parties said they were committed to "sustained dialogue".
Derry Sinn Fein Councillor Lynn Fleming said the groundwork for the alliance had been laid over some weeks.
"We are a society coming out of conflict and if we are to have a shared future we need to sit down with our unionist neighbours," she said.
The statement said: "We must be confident in building a better future for ourselves and our children.
"We must show leadership and not be afraid to take risks.
"In this regard our two parties have committed to and embarked upon a sustained dialogue to develop initiatives based upon common and agreed community issues that will function within and between our communities."