President Corazon Aquino's difficulty in extending her authority to provincial and local governments is a growing source of concern to her supporters here, who, along with political commentators, believe she is moving clumsily in this matter and risks splitting her fragile coalition.

Political analysts and Aquino supporters agree that her government must quickly dismantle the political patronage machine with which former president Ferdinand Marcos controlled the countryside during his 20 years in power. But disagreements over how to share control of local governments have intensified and focused attention on the latent tensions between the two main parties in Aquino's coalition government.

More than any policy issue, the questions that have troubled Aquino's coalition have been those -- such as government appointments and the abolition of the National Assembly -- that will determine which parties will get to keep their political bases in the new regime.

In the clearest demonstration of the apparently growing split, a senior leader of the United Democratic Organization (Unido) -- the larger and better organized party in Aquino's government -- late last month denounced her "dictatorial orders," which he said were favoring the smaller coalition partner.

Among various politicians, diplomats and commentators interviewed in recent days, there were no suggestions that the growing tension in the coalition immediately threatens Aquino's government. But, as Aquino tries to balance and stabilize the odd mix of traditional politicians, military reformers, civil rights lawyers and businessmen now running the country, the partisan squabbling -- and Aquino's failure to quash it -- worries many.

"What we need most is stability, and this is creating instability," said Homobono Adaza, a leading member of Unido.

Some Philippine and foreign observers go further, suggesting that Aquino has a unique opportunity to cut back the traditional patronage system, which evolved over centuries and was chronically corrupt long before Marcos. They contend that she risks losing her best chance to defuse a Communist insurgency if she fails to act decisively against the patronage system and the abuses that have turned rural populations toward the Communists.

"If she asserted her moral leadership in the countryside, she could cut down on the corruption that helps feed the Communists -- although she'd never get rid of it completely," a western diplomat said.

In this nation of more than 7,000 islands, where it historically has been difficult for central governments to assert authority, local government is seen as particularly important.

"To control this country, you must control local governments," a diplomat said, "and Marcos used his party as his personal machine to do this."

Aquino has repeated publicly that she wants appointments to local governments -- as well as to government agencies and corporations -- to be made on merit rather than political affiliation, but breaking the Philippine patronage habit has proven difficult.

Doubts about the strength of the coalition have persisted ever since it was formed last December. Against the wishes of some party leaders, Unido chief Salvador Laurel gave up his own presidential bid to join Aquino as her running mate.

Aquino was already supported by the Philippine Democratic Party-Laban, itself a coalition of two opposition parties, including that of her assassinated husband, former senator Benigno Aquino Jr. She agreed with Laurel to run under the Unido party label.

But now Unido politicians, who believe their party's nationwide organization was essential to Aquino's victory, feel that she is cheating them out of their share of power by favoring PDP-Laban. Unido leaders began grumbling openly when they received only four of the top 20 posts in Aquino's government -- and got none of the key domestic ministerial positions.

Unido, which was by far the largest pro-Aquino party in the National Assembly, lost that source of influence when Aquino abolished the assembly with her provisional government.

The party's number two leader, Rene Espina, accused Aquino of assuming "dictatorial powers" and announced that Unido legislators would join Marcos' party in a defiant protest session of the assembly later this month.

"Cory has not kept her promises to Unido," said Max Soliven, publisher and columnist for the Philippine Daily Enquirer. "Laurel, to his credit, is trying to preserve unity in the government," Soliven said, "but he's getting a lot of flak from Espina and Unido."

Increasingly, Unido members charge that Minister of Local Governments Aquilino Pimentel, a PDP-Laban member, is appointing overwhelmingly his own party loyalists to administer provinces and towns, pending planned local elections. Former Unido legislator Adaza accused Pimentel of naming scores of unqualified appointees -- including his wife's former driver -- to administer a town in Ilocos Sur Province.

"This is pure patronage," Adaza said. "He is choosing PDP-Laban people to try to build himself a political base in the provinces." Press reports quoted Pimentel as responding that the driver and others were appointed for their work on behalf of the opposition movement that elected Aquino.

Guillermo Parrel, a PDP-Laban officer close to Pimentel, denied the charges of patronage. Pimentel "names the appointees on the basis of the recommendations from within the party" but also from outside PDP-Laban, Parrel said.

Nonpartisan observers, such as diplomats and publisher Soliven, agreed with the theory that Pimentel is trying to expand PDP-Laban beyond its current base, largely limited to Metro Manila. "Pimentel seems to be loading the dice for his group, not for the sake of Cory Aquino," Soliven said. "As their unhappiness grows, Unido will look for the right issue on which to challenge Cory," a diplomat said.

Several observers said that Aquino's popular mandate leaves her relatively free of debt to traditional political machines, and to the conservative local and regional elites that have opposed rural reforms such as land redistribution.

One diplomat argued that, moreover, Aquino is a committed opponent of traditional Philippine machine politics because of personal experience: "Her husband's assassination fell well within the bounds of normal Philippine politics."

The diplomat added that in the countryside there is a popular desire for change that Aquino might be able to tap, much in the manner of the popular uprising in Manila that installed her in power. He points to the rapid growth of Bayan, an umbrella group of leftist organizations that was formed last May and within six months organized impressive strikes in various parts of the country.

There is disagreement of the chances for sweeping political changes. Various observers suggest that it would take a long time to build institutions that could spread Aquino's desired reforms throughout the archipelago.

"We are not going to see that kind of change in the near future," Adaza said. "It will take generations, not years," to break down the old political systems, he said.

But even those who are hopeful of fundamental change in the Philippine political system are worried by what they see as a critical lack of resolution from Aquino, and they cite the controversy of local governments as an example. With the appointment issue dividing her coalition and raising protest in towns where popular local officials have been removed in favor of Pimentel's appointees, political observers wonder at Aquino's failure to rein in her minister.

"She should put her foot down, but, as we've seen on other issues, she's just too kind," said publisher Soliven.

"But the fruits of her labor over the next two or three years are going to depend on how well she grasps the mechanisms of power in the first few months," a diplomat said. "She hasn't done it so far."