The Bush administration yesterday confronted two of its most pressing environmental challenges, pleasing some environmentalists with a plan to restrict offshore oil development and outraging others with a proposal on the northern spotted owl designed to save timber industry jobs in the Pacific Northwest.

In the first of two back-to-back news conferences, administration officials announced suspension of planned sales of undersea oil tracts off southern California, northern California, Oregon, Washington, southwestern Florida and New England's Georges Bank pending new environmental studies.

Hours later, environmentalists who had greeted that announcement with praise were denouncing a plan outlined by Interior Secretary Manuel Lujan Jr. and Agriculture Secretary Clayton Yeutter that called for "balancing" the needs of the threatened owl with the timber industry.

As part of the plan, the administration will propose changes in federal laws protecting endangered species so economic factors are given more consideration in deciding how to protect threatened animals.

"I think they're trying to divert attention from this new assault on endangered species," said George T. Frampton Jr., president of the Wilderness Society. "The White House could not have taken a more extreme position toward forest protection . . . I really feel terrible to be in this position when the administration has done such a terrific job on" the offshore oil decision.

Administration officials acknowledged that the timing of the two events was more than coincidence. "There is a certain political symmetry to packaging a very good environmental decision with one that isn't particularly good," one official said.

The offshore oil decision is a substantial retreat from Reagan administration plans for the nation's Outer Continental Shelf, the federally controlled offshore area that generally begins three miles from shore and encompasses more than a billion acres. During the early years of the Reagan administration, then-Interior Secretary James G. Watt caused an uproar with plans to open the entire shelf to development, and Congress responded with a series of temporary drilling bans that remain in effect.

So far, except for drilling off southern California that predated the bans, most offshore development has occurred in the Gulf of Mexico

During his 1988 presidential campaign, Bush announced that he would study planned lease sales in contested areas off California. Politics clearly remained a factor in yesterday's announcement, since Sen. Pete Wilson, the Republican gubernatorial candidate, is dead set against oil development off the California coast and so are most voters in the state.

The president's concession on offshore oil also reflects political reality in Congress, whose opposition was hardened by last year's Exxon Valdez oil spill. It follows the recommendation earlier this year of an interagency task force that called for more study of the California and Florida tracts. A National Academy of Sciences panel also has concluded that the administration does not have adequate scientific information to proceed with offshore leasing.

"The combined effect of these decisions is that the coast of southwest Florida and more than 99 percent of the California coast will be off-limits to oil and gas leasing and development until after the year 2000," Bush said in a statement.

In addition to the California and Florida delays, Bush handed environmentalists several unexpected bonuses, calling for leasing delays off Washington and Oregon and in New England's Georges Bank, as well as a permanent drilling ban in California's Monterey Bay.

While environmentalists were generally surprised by the extent of the delays, the president's announcement did not satisfy those who have been seeking a permanent offshore ban. Nor did it address oil drilling in many other parts of the country, such as off Alaska and the mid-Atlantic states.

"Are they saying that North Carolina is less sensitive than northern California, or that that the New Jersey coast doesn't deserve the same protection as southern California?" asked Lisa Speer, senior scientist with the Natural Resources Defense Council.

Reaction to the spotted owl announcement was far stronger.

The steps outlined yesterday marked the administration's response to last week's decision by the Interior Department to formally declare the northern spotted owl a threatened species. Earlier this year, a federal scientific panel concluded that saving the bird from extinction would require setting aside large areas of the old-growth forests where most of the owls are found as "critical habitat."

But a study by the U.S. Forest Service later estimated that the panel's recommendations would cost 20,000 timber jobs over the next decade, and White House officials then overruled Forest Service officials who wanted to adopt it.

"It is imperative that we find legitimate ways to bring to bear relevant economic considerations in these sensitive decision-making processes," said Yeutter, who oversees the Forest Service. "We want to have the capability of looking at the interests of human beings as well as the interests of non-human inhabitants of this planet."

To that end, Yeutter and Lujan announced creation of an interagency task force to draft a new owl-protection plan. In addition, if the Forest Service is unable to sell timber without jeopardizing the spotted owl, the administration plans to seek an exemption to the Endangered Species Act.

The act allows the administration to convene a Cabinet-level committee to consider exemptions, but officials called for a "broadening" of the committee's powers to set environmental policy. And in what is sure to set the stage for a contentious battle on Capitol Hill, the administration wants Congress to prohibit lawsuits by environmentalists that challenge its actions under the Endangered Species Act and other environmental laws.