The widow of assassinated Philippine opposition leader Benigno Aquino formally was drafted as a presidential candidate today, widening a split in the country's opposition that could erase any chance for victory in an election battle with President Ferdinand Marcos.

Most analysts here give the opposition no chance of winning the Feb. 7 election if the anti-Marcos vote is divided between Corazon Aquino, 52, and the opposition's other front-runner, former senator Salvador Laurel, 57.

Laurel was nominated by his party, the United Nationalist Democratic Organization, last June. Today, a newly formed coalition known as People's Struggle issued a draft for Aquino, who until her husband's assassination in 1983 had played no significant role in politics.

"She is expected to announce her decision to run very shortly," said Jovito Salonga, leader of People's Struggle.

Marcos and his ruling New Society Movement, which called the presidential election now set for Feb. 7, are watching the rivalry with glee from the sidelines.

"The more the merrier," Marcos was quoted as saying recently.

The Philippine opposition spans the spectrum of left to right and includes businessmen, church leaders, labor organizers and conservative politicians frozen out of positions of influence. It has been unable to close ranks against Marcos, who is now in his 20th year of power.

Dogged by reporters and television cameras, Laurel and Aquino have met repeatedly in recent days to try to work out a compromise, a withdrawal by one or a joint ticket. To date, nothing has emerged, and, by many accounts, the hostility between the two camps has grown.

The two have radically different styles and organizations. Laurel, verbose and energetic, represents the center-right and in many ways is a machine politician in the old Philippine style.

He was born into one of the country's large landowning families, and his father was president under the Japanese occupation during World War II. Laurel says he has organizers in 1,500 towns and cities.

"I believe that I can fight Marcos and beat Marcos," he said recently. "We have been working for the last five years organizing this entire country."

The ever-reluctant Aquino, meanwhile, has yet to say definitely that she will run. But few people believe she will turn away now; some, in fact, say a master politician has already emerged. At ceremonies last week to mark the birthday of her late husband, she quoted him as saying, "I will not be able to live with myself knowing that I could have done something but did nothing."

His death thrust her from the role of housewife to spiritual leader of the anti-Marcos movement. Only in recent months, as left-leaning members of the opposition grew increasingly dissatisfied with the prospect of Laurel as the standard-bearer, did people start talking of her as a candidate.

In October, she said she would run if a million people signed petitions urging her to do so. A support group began a nationwide campaign through newspapers and door-to-door solicitation and claimed on Monday night to have assembled 1,005,882 signatures.

Such a drive was unprecedented in Philippine history. Aquino's fans contend that her freshness, sincerity and lack of ties with any machine would carry the day with Philippine voters.

"They do not like politicians, and Cory is not a politician," said Joaquin Roces, using Aquino's nickname. A former newspaper publisher, Roces has headed the drive to draft her.

Emotions have run high in the two opposition camps' feud. Earlier this month, the woman heading an opposition umbrella group set up to select a single candidate to face Marcos, resigned after a heated exchange in a closed-door meeting with Laurel, who accused her of bias against his candidacy.

Laurel's critics within the opposition continue to snipe at him as a copy of Marcos. Columnist Luis D. Beltran, writing in the antigovernment weekly Veritas, said he had a friend who maintains that no one but Laurel can beat Marcos.

"For one thing, he says, no one else can think like Marcos, act like Marcos and be like Marcos enough to be able to replace him," he wrote.

Aquino's critics tend to be a bit more circumspect, given her reputation for prayer and her position of honor in the opposition. They point to her lack of experience and self-admitted ignorance of the skills needed to run a country of 55 million people. The reluctance of male voters to vote for a woman is also cited.

Marcos, meanwhile, has joined in dismissing Aquino.

"She's a candidate you sympathize with but won't vote for," he told the Hong Kong-based Asia Week magazine recently.

Associates say Marcos relishes what lies ahead.

"He's at his best when there's going to be an election campaign, political combat," said Adrian Cristobal, special assistant to Marcos. "He's much more responsive, bouncier, because there's going to be a fight."

Marcos has managed to manufacture some suspense about whom he will pick as his running mate. Speculation continues that he will name his powerful wife, Imelda, who serves on his Cabinet as minister of human settlements.