Plan to Proclaim Bosnia Peace Is Dropped : Balkans: Shipboard talks fail. Muslims want access to sea and more territory.

Western mediators abandoned a plan to proclaim peace across this war-ravaged country today after failing at an eleventh-hour meeting aboard a British warship Monday to ease Muslim fears that a proposed partitioning will be Bosnia’s death warrant.

Only hours before a scheduled truce-signing ceremony, which the mediators had called in apparent hopes of wringing a negotiated settlement out of the warring parties, the would-be peacemakers’ spokesman conceded that the combatants still refused to sign.

Bosnia’s Muslim-led government rejected a formula for division drafted in secret by Serbian and Croatian rebels and demanded access to the Adriatic Sea and more of the territory lost to “ethnic cleansing.”

But both Serbian and Croatian leaders have rebuffed appeals that they withdraw from any more land, and Bosnian President Alija Izetbegovic has said he will not endorse a treaty without those concessions.

“There was a need for all three parties to show some additional flexibility, but it wasn’t sufficient,” the mediators’ spokesman, John Mills, said after six hours of talks aboard the British aircraft carrier Invincible in the Adriatic Sea failed to resolve the remaining territorial disputes.

With no hope of compelling the faction leaders to pledge an end to the 17-month-old war, mediators Thorvald Stoltenberg of the United Nations and Lord Owen of the European Community scrapped plans for the meeting they had called for today at Sarajevo airport.

As if to underscore the receding prospects for peace, fighting between Croats and Muslims continued in several areas of central and southern Bosnia-Herzegovina in violation of a cease-fire that was to have taken force at noon last Saturday.

The latest setback has sparked fears that heavy fighting could resume in Sarajevo, which has been spared severe shelling for almost a month, although machine-gun battles and sniper fire continue to menace the capital.

A spokesman for the rebel Serbs ensconced in this mountain hamlet near Sarajevo that they consider their capital said he doubted the impasse would be the end of diplomatic efforts to end the war.

“I believe this is just maneuvering on Mr. Izetbegovic’s part,” said Slavisa Rakovic, a chief adviser to Bosnian Serb warlord Radovan Karadzic. He predicted that the nearly vanquished government will eventually give in to the rebels’ terms for a partitioning that will create three ethnic ministates.

The mediators have also sought to pressure Izetbegovic into a virtual surrender by warning of the coming winter and the prospects for mass starvation.

Monday’s shipboard session drew together Izetbegovic, Karadzic and Bosnian Croat chieftain Mate Boban, as well as Serbian President Slobodan Milosevic and Croatian President Franjo Tudjman. Inclusion of the latter two amounted to an acknowledgment by the mediators that the Serbian and Croatian heads of state effectively call the shots in the war through their Bosnian proxies.

Tudjman’s spokeswoman, Vesna Skare-Ozbolt, said the Croatian president had no intention of conceding to Sarajevo’s demand that the mostly Muslim ministate include the port of Neum on Bosnia’s minuscule coastline, a predominantly Croat-populated region.

U.N. officials have privately questioned whether Neum could ever be developed into a major shipping terminal, because massive dredging of the shallow waterfront and pier construction would be necessary.

In the face of the international community’s refusal to enforce U.N. resolutions to roll back the nationalists’ war gains, Izetbegovic agreed in July to accept ethnic partitioning as the price for ending the war that has killed 200,000 and driven 2 million from their homes. Most of the casualties and victims of displacement have been Muslim civilians.

But Geneva-based talks to determine the boundaries of the three ethnic ministates collapsed Sept. 1.

Owen and Stoltenberg unexpectedly announced Thursday that they had convinced all three sides to sign a peace treaty today and to put off the remaining land disputes for future resolution.

But in the last few days, all three parties cast doubt on prospects for a truce.

Izetbegovic told Bosnian Radio on Saturday that he strongly doubted the accord would be signed.

Boban later objected to a provision granting Bosnia’s U.N. seat to the government, on the assumption that the Serbian and Croatian ministates will eventually annex themselves to their patron republics.

Monday’s edition of the Belgrade daily Politika quoted Karadzic as saying he would not sign the armistice unless the United Nations agreed to lift sanctions on the rump Yugoslavia, which has armed and supplied his forces throughout the rebellion they launched in April, 1992.

Special correspondent Danica Kirka, in Zagreb, contributed to this report.