A heralded offshore oil agreement between Interior Secretary Donald Hodel and a group of California lawmakers appears to be unraveling, raising the possibility of another congressional battle to renew a moratorium that has blocked drilling off much of the state for four years.

The tentative agreement, announced in July, would have opened 150 tracts of ocean floor -- nearly a million acres -- to exploration.

More than 6,300 tracts would have been off limits until the end of century, except in cases of national emergency.

The pact was widely praised by environmental groups, but Hodel has been under increasing pressure from other administration officials and the oil industry since it was announced.

More than 200 oil firms and drilling companies have blasted the agreement, and Energy Secretary John S. Herrington attacked it last month as "not in the best interest of America's energy future."

In an effort to appease those critics, Hodel now says he will attempt to persuade Congress to revise the agreement and switch some of the agreed-upon tracts with others deemed to have more commercial appeal. In hearings in California last month, "the key question that arose is 'do we have the wrong 150 tracts?' " he told United Press International yesterday.

Environmental groups already have warned Hodel that any attempts to "abandon or significantly alter" the agreement will invite lawsuits and a new push for a congressional moratorium.

Rep. Leon E. Panetta (D-Calif.), who led the California negotiating delegation, said he found Hodel's suggestion "a little surprising," considering that the initial tracts were selected on the basis of the Interior Department's geological analyses.

"We asked Interior to present tracts of the most interest to the oil industry," he said. "My question to him is: What information do you have now that you didn't have then?"

Panetta said California lawmakers were not ruling out minor changes in the tentative agreement, but "at no time did we consider taking 150 off the table and starting over."

The California pact, considered a key step in the administration's efforts to increase offshore oil exploration, was expected to find its way into the continuing budget resolution, which must be passed by Sept. 30. If the agreement with Hodel collapses, Panetta said Congress could either move the legislation without Hodel's support or could attempt to reimpose the moratorium that is due to expire Oct. 1.