Mexico yesterday turned down an American request that it help pay for millions of dollars in damages and cleanup operations stemming from the massive Mexican oil spill that began June 3.

In a sharply worded statement delivered to the U.S. embassy in Mexico City last night, the Mexican government said it was not willing to hold talks about responsibility for damages "because there exists no basis in international law" that could hold it or the state oil company legally responsible.

The contents of the message were made public by the Mexican foreign ministry.

The State Department had announced earlier that Mexico had been asked to help pay the cost of cleaning up the Texas coast, which has been blackened in the largest oil spill in history.

"We believe we should now begin discussions on various issues related to the oil spill," Robert Krueger,the U.S.COORDINATOR for Mexican affairs, had said.

According to a top Mexican government official, Mexico was particularly annoyed that the U.S. message was published in Washington before a Mexican reply had been prepared and because "it implies beforehand that we are guilty. This is not the way to go about it."

Since June 3, up to 30,000 barrels of Mexican light crude oil has been gushing daily from the Ixtox I drilling platform, 600 miles from the Texas coast.

Jorge Diaz Serrano, head of Mexico's national oil company, said his company hopes to cap the well next month. The blowout flow into the Bay of Campeche has been reduced to about 10,000 barrels of oil a day.

The Mexican official said the State Department had "nerve" to suggest that Mexico may have to pay compensation for the spill.

"When has the U.S. paid damages for the vast industrial waste pouring into the Mississippi which has poisoned the Gulf for decades?" he asked. "Or for the damages caused to people's health by lead fallout from the El Paso smelters, or for the salinity of the Colorado River which has caused huge losses to Mexican farmers?"

Mexico has long-standing claims of U.S. pollution of its territority.

The State Department said last night that it would not comment on Mexico's decision until today.

The blowout reportedly resulted from malfunctioning safety equipment operated by Sedco, a prominent Dallas drilling firm founded by Texas Gov. Bill Clements.

Sedco was drilling the well under a contract with Pemex, the Mexican national oil company.

Earlier this month, Clements touched off criticism during a tour of Texas beach communities when he said the spill was "much to-do about nothing."

Yesterday in Corpus Christi the Coast Guard reported that a 35-mile-long oil slick has washed ashore on Padre Island and a Port Aransas oceanographer said a recent shore bird count was down 91 percent from last year because of the spill.

Krueger told reporters that the U.S. government has spent an estimated $3 million for cleanup so far.

Krueger brushed aside suggestions that the United State move to press Mexico for damages was linked to the on-again-off-again natural gas negotiations under way between the two countries since August 1977. "The natural gas talks have been conducted purely as natural gas talks; there has been no linkage" he said.