The Security Council unanimously adopted a landmark resolution today that "condemns unequivocally all acts of hostage-taking and abduction" and calls for the immediate release of all kidnaping victims, "wherever and by whomever they are being held."

It was the first council resolution ever adopted on hostage-taking.

U.S. officials said there had been no information that today's council action might spur the release of the American hostages in Lebanon, but they confirmed that the initiative stemmed from a suggestion by Susan Franceschini, sister of the Rev. Lawrence Jenco, one of the kidnaping victims.

The officials said that recent incidents, such as the Achille Lauro ship hijacking and the kidnaping of four Soviet diplomats in Beirut, had brought home to governments the universal nature of the threat.

After the brief council meeting, at which all 15 members voted for the text but no statements were made, U.S. Ambassador Vernon Walters expressed hope that "all parties that have any influence over groups now holding hostages will take to heart today's clear and unanimous message."

The action makes clear, he told reporters, that "no cause, no excuses, can justify such threats to human rights and human lives."

The resolution also "affirms the obligation of all states in whose territory hostages or abducted persons are held, urgently to take all appropriate measures to secure their safe release and to prevent the commission of acts of hostage-taking and abduction in the future."

It appeals to governments that have not yet done so to ratify various conventions against hostage-taking and other forms of terrorism, and join in the prosecution and punishment of such acts.

It was after Franceschini's suggestion at a Capitol Hill hearing on Oct. 24 that "our ears sort of perked up," said one State Department official.

In early November, Walters conveyed the idea to his Soviet counterpart, Oleg Troyanovsky, and the two worked out an initial draft of the U.N. resolution.

It was discussed at a presummit meeting between Secretary of State George P. Shultz and Soviet Foreign Minister Eduard Shevardnadze, a U.S. official said. It was not until after the Geneva summit meeting later in November that Moscow provided its final agreement to support the resolution. Meanwhile, the other members of the 15-nation council were brought into the consultations, and seven of them -- Australia, Britain, Denmark, France, Peru, and Trinidad and Tobago -- joined the United States in sponsoring the text, after cosmetic alterations.

Earlier, on Oct. 9, a statement issued on behalf of all council members had condemned terrorism in all its forms. At Soviet insistence, that statement also included a specific condemnation of hostage-taking.

Just one week earlier, the four Soviet diplomats had been abducted in Beirut and one was killed.

On Dec. 9, the General Assembly adopted by consensus a resolution condemning as criminal all acts of terrorism. That text was somewhat qualified by references to the "underlying causes" of terrorism, and to the legitimacy of the "struggle for self-determination."

After today's council vote, British Ambassador John Thompson conceded that "it would be naive to think no more hostages are going to be taken, but it is encouraging to see governments agree on steps to fight the problem.