Spain will lend Colombia three military planes and may mediate in peace talks with guerrillas in a bid to back Colombian President Alvaro Uribe's efforts to secure the nation from drug-funded terrorism, Spain's Prime Minister Jose Luis Rodriguez Zapatero said.

Colombia, which is waging a four-decade war against guerrilla and paramilitary fighters, would use the planes to transport troops throughout the country, Zapatero said during a one-day visit to Bogota. Spain also is willing to act as mediator in peace talks between Colombia and guerrilla groups under the condition the Revolutionary Armed Forces of Colombia and the National Liberation Army, the two main guerrilla groups, ``cease hostilities,'' Zapatero said on National Radio.

``We want to be the best ally Colombia has in the fight to create peace,'' said Zapatero, who returns to Spain today. ``There is no justification for the use of arms.''

Zapatero dismissed criticism from former Colombian President Andres Pastrana that Spain would create an arms race in the region by selling military hardware to Venezuela. Zapatero yesterday signed an agreement with Venezuela's President Hugo Chavez to sell eight patrol ships and 10 transport planes to operate along the border with Colombia.

``It is totally false that they will be used to shore up Venezuela's military, or that they will be used offensively,'' he said. ``They are for controlling crime, drug trafficking and guerrillas.''

Last year Spain canceled plans to sell Colombia 40 AMX-30 tanks to operate along the border, where clashes between the two countries have been on the rise since Chavez took office in 1999, because it could cause problems with Venezuela.