Mexico signed a $1.6 billion rescue agreement with the International Monetary Fund yesterday that immediately triggered the promise of $2 billion in World Bank loans and intensified pressure on commercial banks to provide more money to help the country through its current debt crisis.

"The effective implementation of Mexico's courageous efforts to deal with its problems will require the full cooperation of Mexico's commercial creditor banks in Europe, the U.S., Japan and elsewhere," said World Bank President Barber Conable.

His view was echoed at a signing ceremony at the Mexican Embassy by IMF Managing Director Jacques de Larosiere, who called for a "major cooperative effort" by the world financial community "to provide the necessary resources."

Major money-center banks remained noncommittal yesterday, saying they had not been informed about details of the latest rescue plan, which became necessary as Mexico's financial plight worsened because of the sharp drop in the price of oil, its major export. Representatives of the banks said they are unsure how much new money Mexico will want from them, although most sources believed it would be in the $5 billion to $6 billion range over the next two years.

The commercial banks, which hold a large part of Mexico's $98.7 billion debt, the second largest in the developing world, will learn details today in New York from Mexico Finance Minister Gustavo Petricioli, who signed the loan agreements with the IMF and World Bank yesterday.

"The banks are not going to do anything until they take a careful look at the agreement," said one banker. Others raised the question of capital flight, believed to be a major cause of Mexico's debt problems, and said the banks are not likely to pour new money into that country unless they are convinced that it will shape up its economy.

But Treasury Secretary James A. Baker III, who was a behind-the-scenes force, along with Federal Reserve Board Chairman Paul A. Volcker, in forging the agreement between Mexico and the IMF, praised the Mexican government's "growth-oriented" economic program.

The agreement appears to be the first successful application of Baker's debt initiative, unveiled in October, to provide for recovery for debt-strapped Third World nations without subjecting them to an IMF austerity program. Key elements of the Baker initiative are the increased participation of commercial lenders and a larger role in the debt crisis for the World Bank.

In a statement issued by the Treasury Department yesterday, Baker singled out "wide-ranging structural reforms" in Mexico's agreement with the IMF that he said were designed to increase the efficiency of the public sector, promote trade liberalization, reduce subsidies to make prices conform to the marketplace and allow more foreign investment.

De Larosiere said the objective of the new agreement "is to help Mexico deal with its economic imbalance, which has been intensified as a result of the oil price drop. We expect this program to lay the basis for a return to economic growth in Mexico."

The new agreement is precedent-setting in at least two ways: it provides for a contingency investment fund to boost the Mexican economy if growth falls below 3.5 percent next year, and allows for extra financing if the price of oil drops to a level between $5 and $9 a barrel.

The reaction of the banks is critical to the success of the plan.

While U.S. banks are under pressure from Baker and Volcker to join in, they are reluctant to become more vulnerable there than they already are. But without their participation, the banks are unlikely to recover the more than $75 billion that Mexico currently owes them, representatives of the banks said.

The most reluctant to loan Mexico more money are small- and medium-sized banks that joined in the syndicates in the late 1970s at the urging of the money-center institutions that are the major lenders.

Petricoli will present details of the IMF agreement to 150 major bankers at a dinner tonight a New York's Hotel Pierre. "It will be a long meeting," predicted one banker. "There will be a long presentation by Mexico and then there will be a lot of questions."

Among the banks invited are the 13 members of the steering committee representing about 700 private creditors. The cochairman of that group, Citibank Vice President William Rhodes, will meet with Mexican negotiators Thursday. The negotiations could take weeks, banking sources said.

Many questions bankers said they will be asking Petricioli, who will be making his first appearance before the world banking community as finance minister since Jesus Silva-Herzog was fired from the job last month, concern Mexico's plan to reform its economy.

"That will be a key question since we are being asked to spend more money," said one banker. "We don't want the money to flow out in capital flight. We want citizens to bring money back in. They will only do that if they think the economy is strong."

Bankers said they will also ask Petricioli if Mexico has tapped other sources of funds, including cash-rich Japan. In April, Silva-Herzog went to Tokyo seeking cash and investment, and there have been reports in the Japanese press that Japan will provide $1 billion