Philippine President Ferdinand Marcos has claimed for decades that he led a band of anti-Japanese guerrillas during World War II, but the U.S. Army rejected his claim right after the war, according to documents in U.S. archives.

Documents in the archives suggest that Marcos actually worked on behalf of Philippine politicians who collaborated with the Japanese occupation of the islands from 1942 to 1944.

The documents on file in this country and abroad -- some written by Marcos himself during the war -- suggest that Marcos' principal objective during the years of the Japanese occupation of the Philippines was to promote the cause of Jose P. Laurel, who became president of the Japanese-sponsored Republic of the Philippines in October 1943 and took flight with the government in late 1944.

Laurel had put Marcos in his debt in 1940 as the supreme court justice who wrote an opinion overturning Marcos' 1938 conviction for murdering a political opponent of his father.

The documents -- found in the National Archives here, the U.S. records center in Suitland, Md., the MacArthur Memorial in Norfolk, Va., and in the Australian war archives in Canberra -- include elaborate, hitherto unreported detail on the activities of Marcos and of his father, Mariano Marcos, during the Japanese occupation.

One document -- the diary of a Japanese interpreter assigned to the elder Marcos -- confirms that he worked as a propagandist for the Japanese. Another document -- a report from an American colonel who commanded Philippine guerrillas who executed Mariano Marcos -- quoted the father as saying "he had been recommended to the Japanese area propagandist by his son" -- Ferdinand.

Accounts of Marcos' wartime activities put out by his government say he directed sabotage and assassination teams working against the Japanese and oversaw the collection of military intelligence that proved vital to the Allied cause. The documents in U.S. archives, however, show that when Marcos made similar claims after the war in a formal attempt to win recognition (and back pay) from the United States for his anti-Japanese activities in 1942-44, U.S. Army officers dismissed his claims as "fraudulent."

Yesterday's New York Times contained an account of this U.S. Army rejection of Marcos' claim to have led an anti-Japanese guerrilla organization. In the Philippines, Marcos reacted angrily to the Times' story, saying it was part of a "smear campaign" orchestrated by his opponents.

In the Philippines during the war, many patriotic citizens did collaborate with the Japanese after the Japanese expelled American forces from the islands and offered the Filipinos independence. The son of Laurel, the wartime president, is running for vice president on the anti-Marcos ticket headed by Corazon Aquino, widow of slain opposition leader Benigno Aquino. Aquino's father also assisted the Japanese during the war.

Marcos, however, has long courted American support with his version of his wartime exploits against the Japanese and on behalf of the United States.

The U.S. Army has confirmed that Ferdinand Marcos fought on the U.S. side after the December 1941 Japanese invasion of the Philippines -- then a U.S. possession -- until April 1942, when he was taken prisoner with Americans on the Bataan Peninsula. The United States also has records showing that Marcos fought on the American side again from December 1944 until the end of the war.

What Marcos did between the two periods when he was with the Americans is the subject on which new light is cast by the documents described and quoted in this article. Murder Verdict Overturned

Ferdinand Marcos had already achieved notoriety in his native land by Dec. 7, 1941, when the Japanese attack on Pearl Harbor brought the United States into World War II. In 1938 he had been convicted of the 1935 murder of the man who had defeated his father, Mariano Marcos, in elections that year for the National Assembly.

Marcos appealed the conviction. While his appeal was pending -- and when he was periodically jailed -- he studied for and took the national bar examination, placing first. This accomplishment in the midst of his legal fight against the murder conviction created a sensation.

In 1940 the Philippine supreme court overturned the murder conviction. Jose Laurel, then a supreme court justice, and who later served as president of the wartime, Japanese-sponsored Philippine Republic, wrote the decision. Marcos in later years repeatedly acknowledged his debt to Laurel. In a eulogy to Laurel, who died in 1959, Marcos said the court decision not only saved his life but also "returned me my faith in my fellow man and God."

Marcos also has served as a trustee of the Jose P. Laurel Foundation, organized in 1960 to "perpetuate the memory of [Laurel] in grateful public recognition of his patriotic endeavors, sacrifice and achievements . . . "

After his conviction was overturned, Marcos went into law practice, but as a Reserve Officers' Training Corps graduate, he was called into the army as a 3rd lieutenant during the mobilization in the summer and fall of 1941. He eventually was fighting with U.S. soldiers against the Japanese invaders.

Laurel went on to become minister of justice and then minister of interior in the first administration under the Japanese occupation. Among his responsibilities was suppression of anti-Japanese guerrillas, bands of irregular forces that appeared throughout the Philippines after the Japanese victory. Many had been soldiers fighting with the Americans.

The first intriguing mystery about Marcos' life during the Japanese occupation concerns his release from a prisoner-of-war camp. Marcos has said he was freed on Aug. 4, 1942. According to an official Japanese statement, occupation authorities at that time were releasing two categories of Philippine prisoners -- those with severe health problems and those "whose families have cooperated with the Japanese military authorities."

Throughout the summer of 1942, the Manila Tribune published the names of ailing prisoners as they were released. Ferdinand Marcos' name did not appear on any of those lists.

But Marcos may have qualified for release on the basis of his family's cooperation with the Japanese. His father, Mariano, participated in a ceremony welcoming the Japanese to Laoag, capital of the Marcos' home province of Ilocos Norte, in early 1942, according to an intelligence report in the files of Gen. Douglas MacArthur's command. The elder Marcos, a former congressman and provincial governor, later spoke at a pro-Japanese rally on July 17, 1942, in Batac in Ilocos Norte, according to the same intelligence report.

Ferdinand Marcos, according to his own version of these events, was arrested by the Japanese Kempei Tai, the political police, immediately after his release from the POW camp, and was taken to Fort Santiago prison in old Manila. There, he has said, he was tortured in an effort to make him reveal what he knew about the plans of some guerrillas to flee to MacArthur's command in Australia. However, an association of former Filipino inmates of Fort Santiago prison has disputed Marcos' claim that he was imprisoned there, and has refused to accept him as a member of their group.

Marcos has said he escaped from the Kempei Tai and took refuge with a guerrilla group in the countryside.

Over the years Marcos and his spokesmen have given two conflicting versions of how he spent 1943. According to the latest version, Marcos spent most of the year on a harrowing odyssey through the Philippine archipelago to establish radio contact with MacArthur's headquarters. But documents from the period of the Japanese occupation, some of them written by Marcos himself, place him in Manila for most of the year.

It was a crucial year. The Japanese, searching for some formula to galvanize Filipino support for Tokyo's concept of the Greater East Asia Co-Prosperity Sphere, announced in May that they were ready to grant Philippine independence.

Jose Laurel was named to lead the committee to draft a new constitution, and then to lead the new government. He was outspoken in his admiration for the Japanese political and social systems. For several years during the 1930s, until he was appointed to the supreme court, Laurel was a paid Japanese agent, according to published histories of the Philippines. (On June 6, 1943, Laurel was shot while playing golf, presumably by a guerrilla. He recovered over a period of weeks in Philippines General Hospital in Manila.) Claims of Group Rejected

In all of Marcos' official accounts of how he spent the years of the Japanese occupation, he had described himself as an active member of an anti-Japanese organization called Ang Manga Maharlika (The Nobles). In 1947 Marcos himself submitted to the U.S. Army a history of the organization in hopes of winning official American recognition of its anti-Japanese role during the occupation. In this history, Marcos and his associates are described as directing intelligence units, sabotage teams and assassination squads under the noses of Japanese occupiers. The nerve center of their operations was in a Manila teeming with Japanese agents.

American military officers checked the claims in Marcos' history of the Maharlika and concluded that they were unfounded. One U.S. officer called Marcos' claims "distorted and overexaggerated." The United States declined to grant official recognition to the Maharlika as an anti-Japanese guerrilla force, a fact that undermines Marcos' past claims about his wartime role, but one which sat unnoted in Army archives for 40 years.

If Marcos and the Maharlika were not engaged in anti-Japanese activities, what were they up to? The story of Marcos' father Mariano suggests an answer.

Not only did Marcos' father welcome the Japanese to the Philippines, he became a full-time propagandist for the occupation. With an armed Japanese escort, he toured villages in northern Luzon, the principal Philippine island, making what a Japanese civilian interpreter called "impassioned" speeches on behalf of the Japanese.

In 1945 Mariano Marcos was executed by anti-Japanese guerrillas. The American colonel who commanded the unit involved described the incident in a 1948 affidavit (written in defense of the execution): "When questioned [Mariano Marcos] readily admitted his activities, and stated that he had been recommended to the Japanese area propagandist by his son," a reference to Ferdinand Marcos.

Marcos' own statements and his history of the Maharlika include at least three descriptions of situations in which, he acknowledges, he and his allies were intimately involved with the Japanese. Marcos tries to suggest that these are examples of how clever the guerrillas were and how dangerously they lived, but the descriptions are also open to a very different interpretation -- that Marcos had cordial relations with the Japanese.

In the history of the Maharlika that Marcos gave the U.S. Army, he wrote that at one point "the order was issued for several of the Maharlika officers to seek employment with the Japanese Kempei Tai [political police], with the puppet constabulary and the puppet government."

Also in the history, Marcos wrote that to finance the Maharlika, he and his associates formed a trading company called The Ex-Servicemen's Corp. (TESCO). Offices of the company were located in the Regina Building in Manila -- a risky site for an anti-Japanese organization, as it was one of seven locations in Manila "most frequented by Jap spies and collaborators," according to a Philippine agent's report found in U.S. intelligence files.

In an affidavit and a formal statement on his wartime activities, both written after the war, Marcos described another situation in which he seemed to expose himself to great risk, if indeed he were an anti-Japanese operative. From June to August 1943, he said, he was hiding in the Philippines General Hospital in Manila and was being treated for -- in one of his accounts -- Black Water Fever, or -- in another -- "gastrix [sic] ulcer."

The General Hospital had been taken over at the time by the Japanese as a military hospital. Marcos' stay there coincided with the recuperation of his political idol, Jose Laurel, who was recovering from the assassination attempt on the golf course in June. Files Looked Impressive

In November 1943, Ferdinand Marcos set out from Manila for the guerrilla camp of Col. Wendell L. Fertig, an American officer operating clandestinely on the southern island of Mindanao. That Marcos undertook this mission is confirmed by records from another guerrilla base at which he stopped en route.

On their face, the documents that Marcos brought to Fertig's base camp were impressive. They describe an aggressive young guerrilla leader -- Marcos -- with excellent lines into Manila's top leadership, and who had agents in every province of Luzon.

One of the documents Marcos brought -- preserved in U.S. archives -- was a short, handwritten note to Manuel Quezon, the prewar president of the Philippines still recognized by the United States, and then living in the United States. The note said that the Maharlika "greets Your Excellency with a pledge of loyalty and fealty. We await orders from Your Excellency and General Douglas MacArthur."

A separate letter was addressed to MacArthur: "Your old men from Bataan and Corregidor . . . await your orders and return." Marcos added a request for "immediate financial aid."

Marcos sent along a roster of Maharlika's "general staff and district commanders." His father, the Japanese propagandist, was listed as "inspector general."

The two most detailed documents dealt with the status of Japanese forces in Luzon and with recent political developments, including the installation of the Laurel government.

The "Military Intelligence Report" is extensive and detailed. The report not only lists the number of troops at each camp on Luzon but also the number of trucks, tanks, artillery pieces and other materiel. The information was obtained, the document states, by "a system of simultaneous countings by agents." This would have been a formidable undertaking by itself, but the report adds: "The counting has been repeated three times, the last of which took place on Oct. 31, 1943."

According to this Maharlika "intelligence" report, the Japanese had 142,000 men on Luzon in October 1943, including 10,000 in hospitals. Maharlika rated Japanese morale as "very high" and said "enemy equipment is in very good condition."

Marcos' figures were far off the mark. Historian Stanley Falk, who helped write the U.S. Army's histories of the Pacific campaign, wrote in 1968 that in late 1943 Japanese strength in all of the Philippines grew from 40,000 to 60,000.

The second long Maharlika document Marcos brought to Fertig's camp was called "Memorandum on Political Developments." It amounted to an apologia for Jose Laurel, and an apparent attempt to persuade Quezon, the prewar president, that Laurel was doing his best to uphold Philippine nationalism and follow the precepts of Quezon himself.

The memorandum was not signed, but the author is identified in other Maharlika documents as Modesto Farolan, a cousin of Marcos and a prominent Manila journalist. At war's end Farolan was Laurel's governor in Ilocos Norte province. American troops arrested him for collaboration with the Japanese and turned him over to the Philippine government.

The memorandum describes at length the jockeying for power among various Philippine leaders. It is contemptuous of them all save Laurel: "Nobody in public life seems to doubt his political integrity and honest purpose."

The memo also said Laurel regarded himself as only a surrogate for the popularly-elected Quezon. For example, on the occasion of the signing of a Philippine-Japanese treaty of alliance, Laurel reportedly turned to his foreign minister, Claro M. Recto, and said: "Clarito, you take care of this for Quezon. You sign it, not me."

The memorandum also said that Gen. Manuel Roxas, the man Quezon had designated to act in his name when he fled the islands in 1942, had given Laurel crucial support.

Quezon never saw this memorandum. When it reached MacArthur, the general decided to file it away. Letters Quote Guerrillas

The archives contain other Marcos material from the war including another Maharlika roster forwarded to MacArthur headquarters in the summer of 1944. In this one, Marcos' father Mariano, the Japanese propagandist, is listed as commander of Maharlika's northern forces.

Two other documents of interest are "open letters" from Maharlika, evidently written in late 1943. Documents in the archives attribute one of these to Marcos; the author of the second is not specified, but might be Marcos as well.

Both letters can be read as attempts to discredit the anti-Japanese guerrilla movement. They were distributed in the guise of clandestine guerrilla newsletters that quoted Maharlika's open letters.

The letter not attributed directly to Marcos is addressed to "Juan de la Cruz," a name that to Filipinos combines the American concepts of Uncle Sam and John Q. Public. "Juan," it appears, has sent to "Maharlika" a newspaper article about some killings carried out by guerrillas, and Maharlika offers a defense of sorts for the killings.

Those slain, it says, had engaged in "graft and corruption, cruelty and inhuman treatment to prisoners, lying and deceit while engaged in espionage resulting in the death of comrades."

The anonymous author writes that personally, "I do not believe in war or its necessity . . . . " He says, "Yes . . . I am tired of fighting and hiding . . . More and more these days I dream of home . . . Does the mist still linger in the hollows?"

The author reveals to Juan: "About two weeks ago, I came to town on a mission. I passed by home and many other homes. It was fiesta, and there was laughter . . . there was singing, there was music.

"I found that I was . . . out of tune with the singing and the music . . . . Because in my heart there is no laughter, there is no singing, there is no music. There is only bitterness. Yes, you are right, after all, there is only hardness in my heart. There is only hatred. And I must go on as I am until I can quench this hatred, until I can wash away this bitterness."

In other words, the guerrillas are not fighting for any political objective. They are driven only by hatred, and put their countrymen at risk merely to satisfy their passion. They haven't the sense to return home to join the "laughter" and "singing."

The second letter, attributed to Marcos, was written as a response to a Japanese offer of amnesty of all guerrillas made by Col. Akira Nagahama, commander of the Japanese Kampei Tei in Manila.

Marcos writes that he has great regard for Nagahama's sincerity, and says the offer of amnesty "has wrung from my men and myself tears of regret that we should face gentlemen of honor and chivalry, bearing the Oriental strain of which we are inordinately proud."

Marcos writes that he can even accept Japan's geopolitical objectives, assuring Nagahama that he and his men believe in an "Oriental Sphere of Co-Prosperity." But he sharply rejects the claim, made by the colonel in his offer of amnesty, that the guerrillas were fighting for the United States. Marcos denounces the Americans as "transgressors" who "robbed our country of its independence."

These sentiments are preceded in this open letter by an introduction purportedly written by the editors of this clandestine guerrilla bulletin. Maharlika, it says, "is still groping for the true meaning of Japanese intervention in his native land . . . .

"He cannot admit because of conceit that he has been fighting all this time in vain, for a false cause. But it is the beginning of his conversion into the new way of life of Greater East Asia. The winning tone of the letter of the cultured [Japanese] chief of military police [that is, Nagahama's offer of amnesty to the guerrillas], which convinces instead of threatens and pleads instead of bulldozes, works its way into his heart."