The Security Council issued a unanimous statement today condemning the "unjustifiable and criminal hijacking" of the Italian cruise ship, Achille Lauro, as well as "other acts of terrorism, including hostage-taking."

Although the statement offered no specific remedies for terrorist acts, diplomats said it was the first time in its 40 years that the council had issued any broad-ranging condemnation of terrorism.

The text was read by the presiding officer, U.S. Ambassador Vernon Walters, at a brief council meeting convened after all 15 members had agreed privately on the wording.

Meanwhile, a resolution was submitted to the General Assembly today that would invite Palestine Liberation Organization Chairman Yasser Arafat to speak at the U.N.'s 40th anniversary ceremonies later this month. The resolution, sponsored by India, Iraq, Kuwait, Nigeria, Senegal and Yemen, also would invite Sam Nujoma, president of the South-West Africa Peoples' Organization.

Assembly action was delayed as U.S. and and other western diplomats made intense backstage efforts to prevent it from being put to the vote. They lobbied among Third World delegates with the argument that Arafat's appearance could prove the final blow to the tattered U.N. image in the West.

Privately, U.S. officials reacted with outrage to the proposal, saying it had broken the gentleman's agreement under which all decisions on arrangements for the ceremonies had been made by unanimous consent.

Arafat addressed the General Assembly once before, in 1974. This time, however, he would be taking the floor as an equal to the kings, presidents and prime ministers who will be speaking during the ceremonies from Oct. 14 to Oct. 24. The United Nations previously invited the heads of member governments as well as governments with observer status. The PLO, which has U.N. observer status, has been excluded from participation because the invitation was extended to governments only.