The Commerce Department has unveiled what it calls an agreement aimed at ending all Japanese whaling in three years, but the pact has been blasted by environmental groups as too lenient and by the Japanese government as "extremely unreasonable."

Under the agreement, Japan can violate an International Whaling Commission ban on hunting sperm whales in the North Pacific without having to face the threat of U.S. economic sanctions.

In return, Commerce said, the Japanese will withdraw their objections to the current IWC ban and a broader one that will bar all commercial whaling around the world, beginning in 1986.

Essentially, if the Japanese agree to drop their objections to the bans -- the one way in which countries can legally exempt themselves -- they would be allowed to ignore the bans until 1988. The United States, in turn, has agreed not to pursue economic sanctions, as required under legislation sponsored by Sen. Bob Packwood (R-Ore.). The sanctions would reduce Japan's rights to fish in U.S. waters.

In Tokyo, United Press International reported that Hiroya Sano, director general of Japan's Fisheries Agency and head of the Japanese negotiating team, called the talks "extremely unreasonable."

"It is unfortunate for Japan that there exists such a U.S. law," said Sano, referring to the 1979 Packwood amendment requiring that the sanctions be imposed.

Craig Van Note, executive vice president of Monitor, an environmental consortium here, said the Japanese "really have given up nothing, and in return the U.S. is capitulating on the sanctions. We're livid." He said the "agreement" was really no such thing, because the Japanese can still renege on it later.

Commerce Secretary Malcolm Baldrige said, "The negotiating is over. It is now up to the Japanese to take the appropriate actions to bring an end to their whaling activities."