MANILA, JULY 22 -- President Corazon Aquino decreed a sweeping land reform today, ordering most of the country's agricultural estates, including her own, dismantled and distributed among the Philippines' 2 million peasants.

Aquino signed the long-awaited executive order to fullfill a 1986 campaign pledge and to defuse an explosive political and social issue that has fueled the country's persistent communist insurgency.

The growing expectation here that the government would enact land reform measures has led some large hacienda owners on sugar-producing Negros island to begin buying weapons and training private armies to defend their estates.

Aquino issued the presidential decree five days before the scheduled opening session of a newly elected Congress that many here suspect will be too hamstrung by special interests ever to enact a meaningful land reform program. Once Congress convenes, Aquino effectively will be stripped of the vast lawmaking powers she has enjoyed for the past 17 months since the old assembly, dominated by allies of deposed president Ferdinand Marcos, was abolished.

Aquino's presidential decree, however, sidestepped some of the thorniest questions still unresolved in the land reform debate, leaving it to Congress to decide such controversial issues as the acreage that landowners will be allowed to retain for their own use and the deadline for completing the massive redistribution.

Some political analysts and leftist farmers' groups criticized Aquino's proposal as skeletal and largely symbolic, leaving too many key details for Congress to decide. Other observers predicted that Congress is likely to pass its own watered-down version of a land reform program, setting up the first test of strength here between the president and Congress under the voter-approved, U.S.-style constitution.

"I would like to believe that Congress and the Executive Branch can work hand-in-hand," Aquino said at a news conference. If Congress cannot act within 90 days to draw up the implementing regulations for her program -- including the question of land retention -- then a newly formed executive body will make those decisions on its own without help from the legislature, she said.

Aquino also said that her own family's sugar plantation, Hacienda Luisita in Tarlac, will "definitely" be included under the new program. "Nobody is above the law and that includes me," she said.

Aquino said her brothers and sisters had met and agreed to participate voluntarily in redistributing their estate, but she gave no details as to the timing. Under Aquino's program, landowners are allowed to enter into government-approved voluntary arrangements to distribute their land among farmers.

Under her program, the government will compensate landholders for the "fair market value" of their land, based mainly on a declaration that all landowners must make by the end of the year.

Landowners will be compensated first with 10 percent of the fair market value of their land in cash, and 10 percent in land bonds each year after that. Landowners would be allowed to purchase government assets that Aquino is trying to sell to private owners.

Aquino's program allots $2.5 billion to fund the land reform program over the next five years, with the money coming mostly from the sale of the lucrative assets left behind by Marcos and his business associates, called "cronies" in the Philippine lexicon.

The presidential commission charged with tracking down and recovering Marcos' "ill-gotten wealth," which has been filing lawsuits daily against Marcos and his associates, named a surprise defendant today -- former defense minister Juan Ponce Enrile.

Enrile was a candidate for the Senate in May's election, and will likely be declared the winner of the last of the 24 seats. But the snail's pace of the counting, and some unexpected legal challenges, have prevented the election commission from proclaiming the final two Senate winners, with just five days before Congress convenes.

One commission member said this week that the panel may also file a lawsuit naming Sen.-elect Edgardo Angara, an Aquino ally, for his role in helping the "cronies" when he served as Enrile's law partner. That suit, if filed, would put the commission in the politically delicate position of targeting two Senate members.

Since Spanish colonizers first came here and began distributing land to encourage Spanish settlement and reward soldiers loyal to the crown, Philippine history has been littered with ambitious land reform schemes that have failed for a variety of reasons. Even Marcos announced -- but only moderately pursued -- a plan to redistribute rice paddies and cornfields.

Aquino said her plan differed from past programs because she has included, for the first time, credit support for the peasant farmers who will become new landowners but lack the means to make the land profitable. Also, Aquino's plan covers the vast sugar and coconut plantations -- producing the country's principal export crops -- that have been exempted from most past proposals.

Aquino has been sharply criticized by Philippine and foreign analysts -- and the country's powerful Roman Catholic Church -- for not having moved faster over the last 17 months to make good her campaign pledge, take advantage of her popularity and institute genuine land reform before Congress convenes and any program gets bogged down in the legislative process.

The World Bank also has recommended land redistribution as a way of getting the country to diversify a farming system still heavily dependent on a few crops vulnerable to international market fluctuations.

Today Aquino said the delay was caused not by any lack of commitment, but out of a desire to consult all the parties affected on such a potentially explosive issue.

"We wanted an agrarian reform program that would succeed," she said. "Turning out a program in a hurry and missing out on the needed consultations would not have contributed to success."