More than 1,000 female workers at the unitary authority brought equal pay claims, backed by the Unison and GMB unions, after years of under-payment compared to their male colleagues.

Northumberland County Council could be forced to pay out as much as £40m for an increase in the current pay rates and compensation for lost back pay.

However, the council said today the conditions of the settlement made with the unions was confidential and that it would not release the exact figures.

The agreement comes before the council was to face the trade unions at an employment tribunal this month.

Earlier this year, director of resources at the council Steve Mason, said the council would be fighting the claims all the way to tribunal.

He also told the council's overview and scrutiny committee that whatever the outcome of the tribunal, both sides were likely to appeal.

But today, the spokeswoman said the settlement was a "satisfactory outcome" for the council and the workers.

"The parties are pleased to announce that the equal pay litigation on behalf of female claimants against the council supported by the GMB and Unison has been settled in principle," she said.

"The details are confidential, but the agreement represents a fair and balanced settlement for both parties and a satisfactory outcome for the claimants and the taxpayer.

"The parties believe this provides a solid basis for concluding the Single Status negotiations and building for the future of the new unitary authority."

The claims followed the 1997 "single status" agreement between local authorities and unions, which sought to end pay scales rewarding men and women differently for the same work.