Mexico's stiffening resistance to International Monetary Fund budget-cutting demands is focusing new attention on government plans to divest money-losing industries, a drive officials and business analysts say is being stalled by political and financial obstacles.

More than two years after officials announced Mexico's intention to sell scores of "nonessential" state enterprises, 26 companies have been sold and 45 firms on the auction block "are still looking for customers," Mario Barreiro, deputy minister of energy and state industry, said recently.

"The private sector demands that we put these businesses up for sale, and then they refuse to buy them," a senior Mexican official complained.

The privatization campaign's slow progress is one reason Mexico is finding it hard to conclude negotiations for a new IMF loan pact, the first step in its quest for a $7 billion financial rescue package. To satisfy IMF demands, Mexico must substantially reduce the budget deficit, which, by the latest independent projections, could swell this year to 15 percent of gross domestic product (GDP) -- triple the relative size of the U.S. deficit.

Government disagreements involving budget cuts broke into the open May 17 with the abrupt resignation of Finance Minister Jesus Silva-Herzog, who in his four years in office had consistently favored deeper spending reductions. Silva-Herzog had expected to present a revamped budget plan to IMF officials committing the government to a gradual narrowing of the deficit over the next year to 6 to 8 percent of GDP, government and diplomatic sources said.

Silva-Herzog apparently was overruled by Cabinet rivals who persuaded President Miguel de la Madrid that a further slashing of subsidies to state companies and agencies could provoke a dangerous popular backlash. His sudden departure shocked foreign bankers here, leading many to question Mexico's commitment to spending restraint.

Nearly half of Mexico's deficit is generated by the financing of the country's internal debt, of which 70 percent is directly traceable to chronic state industry overspending, the Private Sector Economic Studies Center recently reported.

In 1985, a year of slumping oil income and higher than expected inflation, the federal government managed to trim its expenditures to 15 percent less than its budgeted allotment, according to the Mexican central bank's annual economic report released last month. Yet state industries, which account for about 45 percent of the federal budget, last year spent 17 percent more than they had been allocated, the central bank said.

State enterprise also has contributed disproportionately to Mexico's foreign debt crisis. As of March, the Finance Ministry reported, government industries owed international banks $29.2 billion, a foreign debt bigger than that of most governments and half again as large as the total debt contracted by Mexico's private sector.

The sale of state industries is a key to narrowing the gap between government spending and income, bankers and Mexican officials long have agreed. But officials and creditors dispute how far and fast privatization can go, with many Mexicans arguing that wholesale divestiture would be tantamount to dismantling the system that has given their country a half century of political stability.

"Some businessmen say they will take these companies over only if they can shut half the place down, cancel labor contracts and fire half the workers," a high-level presidential adviser said. "We can't allow that."

Two weeks ago, the powerful labor arm of the ruling Institutional Revolutionary Party (PRI) proclaimed its opposition to further budget cuts and called for a strengthening of state industry. Such pronouncements are taken seriously: The estimated 2.3 million unionized public sector workers formally affiliated with the PRI constitute the core of the government's political base. Loyalist labor groups fear the loss of thousands of jobs if big state firms are sold, streamlined, or, as appears the only alternative in many cases, shut down.

These political problems must be overcome, some creditors insist. "We are tired of being told that things can't be done because of political taboos," a U.S. banker here said. "How can a government claim that it is nearly bankrupt when it could cancel most of its debts tomorrow by selling steel and petrochemical plants, or a small part of its oil reserves?"

In one vivid warning of the consequences of state factory closures, some 9,000 steelworkers put out of work by the closure of an antiquated government-owned foundry publicly burned their PRI union cards in protest last month. Analysts agree that the government had little choice -- private investors were unwilling to acquire a company that in a decade of state ownership had lost money every year while amassing a $380 million foreign debt. In 1985, according to data presented to employes along with their pink slips, the foundry's operating expenses were $414 million while its sales totaled just $185 million.

"Either this is evidence of a fundamental shift in the government's thinking about state business, or it means that its cash situation is more desperate than we had thought," said Francisco Bunt, the board chairman of Grupo Tolteca, one of many Mexican business leaders who said they were surprised and pleased by the politically difficult decision to close the plant.

Despite the political fallout, the government is preparing plans to shut down several unprofitable, labor-intensive sugar refineries and fertilizer plants, a senior Mexican official said.

In a signal that the privatization effort will proceed, De la Madrid recently reiterated his commitment to divest businesses that are not of "strategic or priority interest." The companies being put up for sale, many of them acquired by the state when they were verging on bankruptcy, comprise bicycle factories, textile mills, luxury hotel chains, supermarkets, tile companies, an airline, nightclubs, auto parts makers and other disparate firms.

"Can this be considered strategic?" a cabinet minister asked, hoisting a bottle of mineral water produced by state-owned Garci-Crespo, one of the largest companies being transferred to private investors. "It is hard to see how making soda water should be a job for the government."

Yet bankers and Mexican businessmen argue that privatization and plant closures should strike far closer to the heart of the government's vast industrial empire. With virtual monopoly control of such businesses as oil and air transport and domination of key industries like steel and mining, state enterprises produce at least a quarter of Mexico's industrial output, economists calculate. In this year's first quarter, with falling oil prices halving the government's normal petroleum revenue, publicly owned companies still accounted for more than half of the country's export income.

Especially singled out by private sector critics favoring divestiture are such giant budget-draining conglomerates as Conasupo, a staple foods importer, wholesaler and retailer, which accumulated a $930 million deficit last year; the Federal Electricity Commission, the government power company, which absorbed some $735 million in subsidies in 1985; Fertimex, a fertilizer manufacturer, which operated at a $295 million loss; and Sicartsa, a sprawling Pacific Coast steelworks, which ended 1985 $245 million in the red.

Yet economic and financial problems also have limited the extent of divestiture, business experts say. Many of these companies, they note, are burdened with surplus capacity, outmoded machinery and massive debts. As is the case with privatization campaigns everywhere, investors want to acquire profitable state companies, while the government is eager to divest money-losing enterprises, analysts say.

Even when proffered state properties are judged economically attractive, there is a critical scarcity in Mexico today of potential buyers with ample spare cash, businessmen acknowledge. Foreign investors, meanwhile, have recently turned down invitations to acquire minority equity interests in government steel mills and engine factories, while meeting resistance in their offers to assume control of potentially profitable state airlines and petrochemical plants, business and government sources report.

Mexican leaders still adamantly reject creditor demands that private investors be invited into areas now legally reserved for the government, among them railroads, power generation and the drilling and refining of oil -- all politically sensitive industries that were controlled by foreigners before their nationalization.

The government "will never, never, never relinquish those strategic enterprises which, if not under our control, would place us at the mercy of foreign minority interests," De la Madrid said last month.