MEXICO CITY -- Mexico's tough-minded treasury secretary has become the first political casualty -- some say scapegoat -- of Mexico's two-week-old currency crisis.


President Ernesto Zedillo sacked Treasury Secretary Jaime Serra Puche on Thursday and announced an emergency program to confront the financial crisis triggered by the peso's plunge. Zedillo said Mexico would accept an international financial package to help stabilize its economy.


"To undertake and execute this emergency economic program with the credibility demanded by the circumstances, I have accepted the resignation of Jaime Serra Puche," Zedillo said.


"We recognize that we underestimated the problem, and that his underestimation was very grave," he said.


Zedillo's comments were his first public answer to criticism from Wall Street and elsewhere that his month-old administration had lost control of the economy. The ouster of Serra Puche was the first Cabinet shakeup since Zedillo began his six-year term on Dec. 1.


"People wanted blood," said Felix Boni of the Mexico City stock brokerage firm Interacciones.


Serra Puche had spent only 19 days on the job.


Mexico's currency crisis began on Dec. 20 when the peso was devalued. The government two days later said it would stop supporting the currency, which led to further declines that pushed its value down more than 30 percent.


At the root of the peso's difficulties was speculative selling that began months ago and worsened due to tensions between the government and rebels in southern Chiapas state.


Angry foreign investors accused Zedillo of misleading them. "The government said all along it wouldn't devalue. Overnight, it devalued," said David Solin of Foreign Exchange Analytics in New York.


Solin noted Serra Puche had told Mexican media late Dec. 21 that the government would no longer support the peso. Foreign investors weren't advised until the following day, and U.S. investors lost as much as $10 billion in Mexican stocks during the crisis.


"I think Jaime Serra Puche put his head on the plate ... saying the peso would not be devalued when it was clear there was a lot of pressure to devalue it," said Sergio Sarmiento, a private analyst.


Serra Puche had served as commerce secretary under past President Carlos Salinas de Gortari and was highly regarded as Mexico's negotiator for the North American Free Trade Agreement. He, like Zedillo, was a graduate of Yale University.


The ousted treasury secretary will be replaced by Guillermo Ortiz Martinez, the current communications and transport secretary.


Zedillo said in his comments Thursday that his economic plan would fight wage and price inflation and count on unspecified emergency funding from the world community.


The United States, Canada and the other members of the Group of Seven industrialized nations have discussed a package of up to $10 billion to help stabilize the battered peso. Officials here and in Washington said Mexico has so far not drawn on a package of currency swap loans to stabilize the peso.