November 26, 1983

Most of the two million square feet of unused air rights that remain over Grand Central Terminal are being acquired by a real-estate partnership that plans to use them for development near, but not above, the landmark depot. The partnership, First Boston Real Estate, a subsidiary of First Boston Inc., is studying five sites, one of which it owns, for the transfer of at least 1.5 million square feet of air rights. Frederick W. Rovet, vice president of the Penn Central Corporation, which owns the air rights, said the agreement with the partnership ''eliminates forever the threat of building over Grand Central Terminal, the tabernacle of transportation.'' Site Occupies Entire Block That threat seemed largely removed in 1978 when the United States Supreme Court sustained a refusal by the city's Landmarks Preservation Commission to allow a proposed tower to be built over the terminal. The ruling, however, focused on the specific Penn Central proposal but did not preclude the development of other plans. Neither Mr. Rovet nor G. Ware Travelstead, chairman of the partnership, would discuss the value of the air-rights transfer.

The Foreign Ministers of Syria and Saudi Arabia announced today that rival Palestinian factions had agreed to stop fighting here and withdraw from the area within two weeks. But the Palestinians later cast doubt on whether the agreement would be put into effect. At a news conference here, Yasir Arafat, the chairman of the Palestine Liberation Organization, said the forces opposing him had sent in reinforcements overnight and that ''we expect tomorrow they will try another big attempt.'' Saturday is the day that rebels in the P.L.O. have threatened to begin fighting Mr. Arafat in the streets of Tripoli. In Damascus, the Syrian capital, Col. Abu Khaled al-Omlah, the chief of staff of the rebels, indicated that his faction was unwilling to comply with a provision of the agreement that requires the withdrawal of all Palestinian guerrillas from Tripoli and its environs. 'We Will Never Leave' ''We will never leave these camps,'' Colonel Omlah said of the Beddawi and Nahr al Bared refugee settlements near Tripoli. ''They are our camps. We are the only ones who can insure the protection of our people in these camps.'' At his news conference, Mr. Arafat seemed not to have seen the full text of the agreement, which was announced in Damascus, and possibly had not given his final endorsement.

News Analysis MOSCOW, Nov. 25 - In the aftermath of the Soviet withdrawal from the Geneva talks on medium-range missiles, Western diplomats here say they believe that whatever chance there was of a settlement may have fallen victim to the leadership uncertainties in the Kremlin. Principal among the uncertainties is that Yuri V. Andropov appears to be slipping in authority because of illness. As a result, diplomats say they doubt there has been any voice in the Politburo strong enough to argue for more flexibility in Geneva. Developments in the missile talks this week have followed a script set out months ago by Moscow. Mr. Andropov and other leaders had long warned that once deployments of new American missiles in Europe began, there would be no ground for continuing the Geneva negotiations.

The Reagan Administration took a cautious stance today toward reports that Nicaragua had been making conciliatory gestures toward domestic opponents and reducing political support for the guerrilla movement in El Salvador. Both White House and State Department officials questioned whether the Nicaraguan leaders were seriously seeking a political settlement of the conflict in Central America or undertaking token gestures intended to ease pressures on the Sandinista regime. Senior officials acknowledged interest in what the State Department characterized as ''the current relaxation of restrictions'' against internal political critics in Nicaragua, as well as other moves by the Sandinista leadership in Managua. 'Feeling the Heat' ''I think they're feeling the heat,'' said one senior official. ''The $64,000 question is: Are they just sending signals or are they serious?''

Poland is so eager to earn hard currency to prop up its battered economy that the Government is taking a loss of as much as $9 million by reselling Libyan oil on the open market, according to industry sources. The decision dramatically illustrates the plight of the Polish economy, which is heavily dependent on Western raw materials and spare parts and has been deeply affected by a cutoff of credit from Western nations. In effect, Poland is increasing its overall debt to obtain dollars needed to buy Western materials. But viewed another way, Poland is converting a credit granted by Libya into hard currency at relatively low cost.