The biggest environmental battle of late 1970s, the campaign for the Alaska Lands Act, has reopened over an administration-backed drive to allow sport hunting in several Alaskan national parks.

On one side is a formidable lineup of conservative and pro-hunters' organizations, rallying behind legislation sponsored by Sen. Ted Stevens (R-Alaska) to reopen 12 million acres of national parks in his state to big-game hunting.

Sport hunting is banned in national parks, and many hunters' groups opposed the Alaska Lands Act for that reason. The act created 24 million acres of national parks along with vast wilderness areas and wildlife refuges.

Interior Secretary James G. Watt, a hunting enthusiast, has expressed support for the principle of the bill, if not the exact acreage. Also on board and flooding congressional offices with letters of support are the National Rifle Association and the Wildlife Legislative Fund, a hunters' lobby founded by G. Ray Arnett, assistant interior secretary in charge of parks.

These supporters portray the bill as "the most significant hunting issue in history," in the words of Grits Gresham, shooting editor of Sports Afield, who is one of many outdoors writers editorializing for the bill.

But an imposing lineup of environmentalists launched a counteroffensive yesterday aimed at persuading Congress that the Stevens measure is not a hunters' bill but rather "the most bald-faced, wholesale assault on our national park system in its history."

At a news conference yesterday they announced the revival of the 10-million-member Alaska Coalition that fought for the Alaska Lands Act, complete with endorsements from such prominent supporters of the 1980 act as former president Jimmy Carter, former interior secretary Cecil D. Andrus, photographer Ansel Adams and conservationist Marlin Perkins, host of the television show "Wild Kingdom."

"Every senator and congressman who supports this bill will have to face being seen as a midnight murder squad for the national parks," said Paul C. Pritchard, president of the National Parks and Conservation Association.

The bill would reclassify 12 million acres of eight national parks in Alaska as "national preserves," meaning they would be reopened to big-game hunting. Stevens and his supporters argue that this simply would give sport hunters equal rights with subsistence hunters, who retained the right to hunt in Alaska's national parks.

But the coalition's leaders called the bill a premature attack by special interests on the Alaska Lands Act and the wildlife balance it was designed to preserve. They also called it a dangerous precedent that could lead to hunting in national parks in the lower 48 states as well.

"It's ludicrous for somebody to say we're anti-hunting," said Andrus, a sport hunter. He said only 8 percent of Alaska is closed to hunting, and most of Alaska's prized game--caribou, grizzly bears, Dall sheep and moose--live outside the parks.

"Do they want it all? Do they want no sanctuaries?" Andrus said. "I'm pro-hunting, but I'm also pro-national parks."

There was a noticeable absence at the environmentalists' news conference, though: the National Wildlife Federation, largest of the big environmental groups but also the one with the heaviest hunters' constituency. The federation is nominally supporting the Stevens measure, in deference to its conservative membership, but has declined to testify on it at the first hearing Friday.

Coalition leaders said they fear the administration is using the issue to break the fragile alliance between them and hunters in battling other Watt initiatives.

They recalled a 1981 interview with Field and Stream magazine in which Watt said: "In a conflict between preservationists and sportsmen, we're going to the sportsmen . . . . If there's to be a wedge driven between the conservation community, we'll help drive the wedge."