Opposition presidential candidate Corazon Aquino, touring southern Mindanao Island and describing it as "a war zone," pledged today to redress immediately the "legitimate grievances" of Moslem and Communist insurgents if she wins an election set for Feb. 7.

In an address she characterized as a "major policy speech" on social justice, Aquino also vowed to revitalize the Philippine armed forces by "immediately retiring all overstaying generals" whose terms have been extended beyond mandatory retirement age and by providing "leadership by personal example."

Aquino made the statements after learning upon her arrival here that a godson had been killed by unidentified armed men in an ambush yesterday in her home province of Tarlac while working for her campaign to unseat President Ferdinand Marcos.

In a question-and-answer session after her speech, she called on Marcos to investigate the killing of Jeremias de Jesus, a local opposition leader in Capas, Tarlac.

"I feel sure this is a political killing," Aquino said. "I asked Mr. Marcos to look into this and stop all of these killings. I hold him responsible for any killings of my political leaders."

De Jesus was the second political organizer for Aquino killed in Tarlac in the past two weeks, aides said. He was shot on a road by a man on a motorcycle, then finished off by men armed with M16 rifles, an aide said. Aquino campaign officials said another of their workers was killed two weeks ago.

Aquino delivered her policy speech after a motorcade into an area of Davao del Norte Province where rebels of the New People's Army, the armed wing of the Communist Party of the Philippines, have been active.

Addressing a crowd of about 10,000 at dusk in the town of Tagum, she said that, if elected, she would negotiate with rebel leaders in an effort to end the bloodshed of the growing insurgency.

"I will call for a cease-fire for six months," Aquino said. "I will talk with the leaders to stop the killings, to find out what their demands are, what they need and what we can do for them." She reiterated her denial of Marcos' accusations that she and her advisers are allied with Communists.

"I am not a Communist," she said. "I do not like any killings, so I will ask the Communists to talk to me to stop all the fighting and get together for the good of our country."

The New People's Army began waging what it calls a "protracted people's war" against the Marcos government in 1969 with fewer than 100 fighters but since then has grown into a nationwide insurgency with about 12,000 guerrillas. The U.S. government has expressed concern that unless sweeping reforms are introduced in the Philippine military to help deal with the insurgency, it could lead to a massive civil war within three to five years.

At a banana and coconut plantation that Aquino visited near Tagum, a manager said that the New People's Army has "killed 30 of our people over the last two years." He said the 30 employes included 14 security guards on the 5,700-acre plantation, which has about 5,000 employes.

As in other campaign swings she has made in recent weeks, thousands of people lined Aquino's motorcade route and waved yellow flags and ribbons as she passed. Many wore yellow T-shirts, caps, headbands and other paraphernalia as they waited for hours in the rain to cheer and wave at her. Yellow ribbons -- the color identified with her campaign -- were tied around trees, telephone poles and even dogs, cows and goats along her route.

In her speech later at a gymnasium in Davao, the Philippines' third-largest city, Aquino lamented that "Mindanao, the land of promise, has become the land of broken promises littered with the bodies of broken and mangled Filipinos."

She told about 3,000 persons, mostly students, that Marcos compounded a Moslem secessionist rebellion by driving to Mindanao Communist insurgents "who were battling his unjust regime in the northern parts of the country and pursuing their vision of a just society."

Marcos' depredation of Mindanao's people and resources, she said, "assured the insurgents a good reception." She accused Marcos of having "laid the foundation for a lasting war of brother against brother Filipino, a war marked sometimes by unimaginable cruelty by both sides and untold suffering of hapless civilians."

Regarding what she described as "the ideological aspect of the insurgency problem," Aquino said that she had "no illusions that ideologies destructive of true democracy will easily die." But she said such ideologies "will not flourish where people are happy and content. Such ideologies will merely stay in the periphery of national life."

Aquino said that the once prestigious Philippine armed forces had been "demoralized and dishonored by the Marcos regime," and she pledged to restore and revitalize the military ideal. Under Marcos' 20-year rule, she said, the military has been "transformed into an object of mockery and hatred."

Aquino said she expected Marcos to accuse her of having stolen his social ideas, as he had already accused her of stealing his economic program after a policy speech on Jan. 6.