Mexican Finance Minister Jesus Silva Herzog ended three days of talks yesterday with Reagan administration officials without a commitment for further financial help from the U.S. government, sources said.

The discussions, which at times also included Federal Reserve Board Chairman Paul A. Volcker, were requested by the Mexican officials, who have said that, because of falling oil prices, they need $9 billion to help them with their balance-of-payments requirements.

Sources said that the American view expressed to the Mexicans was that Mexico can meet its payments with funds that already are committed to it.

The sources said the Mexicans are beginning to think about elections that will be held in two years, and want the $9 billion to help them avoid reducing their domestic spending to meet their international obligations.

The U.S. position has been that the Mexican government needs to improve its internal financial problems before it can expect more help from outside. Treasury Department and Fed officials refused to comment on the meetings.

New York bankers who hold some of Mexico's debt said that the Mexicans did not hold formal talks with them yesterday as expected and left for Punte del Este, Uruguay, where the Cartegena group of 11 leading Latin American debtor countries is meeting to discuss what to do about the region's $370 billion debt.

Mexican President Miguel de la Madrid said in a speech on Friday that his country needs another approach to the worsening debt crisis in light of the sharp collapse of oil prices in recent weeks. Mexico is a major oil exporter and relies heavily on oil revenue.

The most controversial aspect of de la Madrid's speech was his suggestion that Mexico will have to limit payments on its debt because of plummeting oil prices. However, de la Madrid stressed that Mexico does not plan to take unilateral action against the banks and that the country will have to cut its budget to replace lost oil revenue.

Mexico owes nearly $100 billion to foreign banks and has said that it may not be able to pay its current obligations, which would be about $12 billion this year.

"Now it is the turn of our creditors to make at least an equivalent effort to the sacrifices made by the people of Mexico," de la Madrid said in his speech on Friday, suggesting to analysts that Mexico wants at least to get an agreement from the lenders to reduce the country's interest costs.

The Cartagena group is scheduled to discuss an Argentine proposal to limit interest payments.

In testimony yesterday before the House Banking Committee, Volcker did not discuss Mexico by name, but said that the adverse effect on oil-exporting debtor nations of the fall in oil prices "should be manageable if there is cooperative effort among all involved parties here and abroad."