The Carter administration will give "the highest environmental priority" to setting aside vast wilderness areas of Alaska. Interior Secretary Cecil D. Andrus said yesterday.

However, Andrus told a House Interior subcommittee, the administration will postpone until the fall recommendations on how much land should be protected from development.

Industry and conservationists are battling over millions of acres in Alaska, where some of the nation's most spectacular scenery sits atop some of its richest mineral and energy reserves.

Congress is preparing to set aside the largest chunk of parkland in the nation's history and the stakes, environmental and financial, are enormous.

"In Alaska, this nation should exercise the opportunity, lost forever in many areas of the lower 48 states, to protect whole ecosystems," Andrus said.

However, developers, backed by the state, say that protecting those ecosystems would lock up potential oil, coal and mineral reserves important to the United States' energy future.

This year is the deadline Congress set for the final major disposition of Alaska territory, which has been largely owned by the federal government since its purchase from Russia in 1867. Congress already has given away 40 per cent of Alaska - 104 million acres to the state and 44 million acres to Eskimos and Indians.

Now, a bill sponsored by Interior Committee Chairman Morris K. Udall (D-Ariz.) and 79 members of Congress would designate 115 million acres as federal wilderness, prohibiting roads, vehicles, buildings or commercial development in the area.

The Udall proposal goes significantly beyond the Republican administration's temporary designation of 83 million acres - an area equal to the New England states plus New York and New Jersey.

Sen. Ted Stevens (R-Alaska) is expected to introduce a bill calling for 25 million acres of parkland with an additional 55 million acres administered by a federal-state commission and open to some development.

The issue has sparked a massive letter-writing campaign from environmental groups such as the Sierra Club, Friends of the Earth and the National Audubon Society. Lobbying on the other side are industry representatives such as the American Mining Congress and the Kennecott Copper Corp.

We stand on the threshold of what could be one of mankind's most epochal conservation achievements," Wilderness Society director George D. Davis said. "In the rest of the country, we see only the remnants of a once-limitless wilderness after years of settlement, resource development and growth.

"In Alaska we have the last opportunity to set aside great pristine, unspoiled expanses first; the opportunity to make wise choices ahead of time about where development is to occur and where conservation is to be given priority instead."

Andrus told the subcommittee that, in setting aside the 83 million acres in 1973, "to a great extent, significant mineral deposits were excluded from the areas recommended for parks and refuges." He said his department is studying the area's geology in more detail.

Andrus said he will not support designating all the land that Udall wants as wilderness. "If all such areas were designated wilderness, it would severely restrict mineral extraction, pipelines and other transportation needs, as well as access to state and native lands," he said.

However, under questioning, Andrus said he does not favor the proposal by Stevens and Alaska Gov. Jay S. Hammond to have most of the land administered by a federal-state commission.

State officials are "asking for a lot of control over land that belongs to the people of the 50 states, without contributing that much themselves," he said.

Alaska's sparse population of 400,000 - somewhat more than half that of Price George's County - is served by only 2,744 miles of paved roads, about the same number as in the District of Columbia and Montgomery County combined, Stevens told the subcomittee.

The impact of designating large wilderness areas "can be tremendous by prohibiting dogsleds, snow machines and other modes of transportation on land as well as precluding riverboat transportation," he said.

John Lagrange of Kennecott said no more than 15 million acres should be closed to mining, timber and other commercial development "in an era of shortage in many mineral and energy commodities."