MADRID (Reuters) - Spanish unions are considering launching a general strike against austerity measures on November 14, union sources said, eight months after the last walk-out and coinciding with strike action in neighboring Portugal.

Workers in both Spain and Portugal are suffering wage cuts and tax hikes as part of government programs designed to keep the countries' finances under control.

Spain, which is also battling 25 percent unemployment, is soon expected to request a euro zone credit line to help cut its borrowing costs.

The country's two largest unions - Comisiones Obreras (CCOO) and Union General de Trabajadores (UGT) - will make a definitive decision on the general strike on Friday, union sources said.

Portugal's biggest umbrella union, the CGTP, announced plans earlier this month to hold strike action on the same day.

(Reporting by Manuel Maria Ruiz and Borja Gonzalez; Writing by Tracy Rucinski; Editing by Alison Williams)