BOSNIANS SEEK TO EXPLOIT NATO AIR STRIKES (sw) By KIT R. ROANE c.1995 N.Y. Times News Service SARAJEVO, Bosnia-Herzegovina As NATO warplanes took advantage of clearing skies to pound Serbian targets near Sarajevo, the forces of the Bosnian government were reported to be exploiting the weakened position of the Bosnian Serbs to retake small parcels of territory. In attacks over the last several days, the Bosnians retook an important route to their industrial center of Tuzla and launched small operations, some in conjunction with their Bosnian Croat allies, on several fronts in central and western Bosnia. So far, U.N. officials and Western diplomats say they are unconcerned about the Bosnian government and Bosnian Croat troop movements because they involve land that is likely to go to the Muslim-Croat federation if a peace settlement is reached that divides up the country. But Western diplomats said that larger Bosnian offensives could endanger not only the peace effort but also the ongoing campaign of air strikes. ``It could add political pressure to stop these operations,'' said one European diplomat. ``NATO has always said that these air strikes were not meant to punish the Bosnian Serbs or wage a war party for the Bosnian government. But there is already concern in Moscow that we have taken sides,'' he said. ``If others begin to grumble, then the NATO may find it wise not to continue.'' As the NATO planes continued their attacks, President Clinton on Tuesday began sounding out members of Congress about a $500 million first installment in a multi-billion-dollar reconstruction fund to rebuild Bosnia if peace is secured. Asked about the $500 million figure at Tuesday's White House briefing, the president's spokesman, Michael D. McCurry, said: ``I wouldn't dispute that one estimate. That's among several estimates that are floating around.'' Noting the administration's sensitivity to Congress' reluctance to increase any foreign spending, even for peacemaking in Bosnia, McCurry said, ``We frankly don't want to frighten Congress with what the bill will be.'' McCurry also stressed that ``it's a long ways away before the United States will be paying for any reconstruction in Bosnia'' because the war is still raging. In an interview on the PBS MacNeil/Lehrer NewsHour, Defense Secretary William Perry said on Tuesday that Serbian air defenses in eastern Bosnia had been devastated by NATO attacks, and allied warplanes will be able to fly over Bosnia ``with impunity'' within a few days. This week, American envoy Richard C. Holbrooke will return to the Balkans and his shuttle diplomacy, seeking to flesh out the principles agreed to in Geneva last week under which the Bosnian-Croat federation and the Bosnian Serbs would divide the country. The Bosnian government has pledged not to take advantage of the NATO air campaign in the immediate vicinity of United Nations-declared ``safe areas'' such as Gorazde and Sarajevo. But the Bosnian prime minister, Haris Silajdzic, said during a press conference on Monday that the government had offered no assurances that it would not attack in other strategic areas. ``We never said we would stop our operations,'' said Silajdzic. ``A commitment was asked for as much as Sarajevo is concerned, and we made this commitment.'' Aleksandr Ivanko, a U.N. spokesman in Sarajevo, said: ``We hope that they exercise maximum constraint in their activities. We have asked them to restrain themselves around safe areas and we hope that this will continue. But we are watching them very closely.'' NATO has taken pains to avoid changing the balance of power in the region but as the air strikes against a broad array of Bosnian Serb targets continue, it may become unavoidable. ``We do not want to tilt the military balance, but clearly these air strikes play to the government troops' advantage,'' one U.N. official said. ``We have devalued the Bosnian Serbs' military capability by hitting supply routes, communications centers and ammunition dumps and we have destroyed their air defense system in eastern Bosnia. That has to affect them.'' Silajdzic said that Bosnian troops had taken an important road connecting Zenica to Tuzla in northern Bosnia. Last summer, in a similar but unsuccessful effort to open portions of the route that were blocked by the Serbs, the Bosnian government lost hundreds of lives in a disastrous offensive. Their success this time may reflect a weaker position of the Serbs or it may mean, some diplomats here think, that the Serbs are prepared to concede a zone of central Bosnia to the government: under the terms of the peace plan under discussion, the Serbs will have to give up about one-third of the territory they have conquered in any case. Other government troops are fighting to regain a road to the central Bosnian town of Donji Vakuf, a move that would open the way for government forces to push on to Jajce, the site of an important power plant. There appeared also appeared to be movement on Tuesday by Bosnian Croats near Titov Drvar, which one U.N. official said could foretell an attempt to link with Bosnian government troops in Bihac to the north. NATO air strikes were authorized 14 days ago, after a Bosnian Serb mortar round killed 43 people and wounded more than 80 in a crowded Sarajevo market area. NATO's explicit goal has been to force the Bosnian Serbs to remove heavy weapons from around Sarajevo and lift the siege there. Gen. Ratko Mladic, the Bosnian Serb military commander, has so far refused to retreat from his positions around Sarajevo, arguing that the Bosnian government could launch an attack in the area if he did. There have been few public comments by the Bosnian Serbs about the Bosnian government's recent territorial gains. But the air strikes continue to be the subject of heated exchanges between NATO and the Bosnian Serb leadership in Pale. In an open letter to Clinton, the Russian president, Boris N. Yeltsin, and the British prime minister, John Major, Radovan Karadzic, the leader of the Bosnian Serbs, accused NATO of ``declaring war on the Serbs.'' Foreign ministers from Bosnia, Croatia, and Serbia, the last representing the Bosnian Serbs, signed a U.S.-brokered statement of principles in Geneva on Friday that would separate the country into two roughly equal entities that would remain part of one state. The Muslim-Croat federation would govern 51 percent of the country, while the Bosnian Serbs would rule the rest. Difficult negotiations to flesh out the terms of an agreement will resume this week. But on Tuesday, Karadzic said that the raids could disrupt the deal. ``In the light of the continuing attacks, at the receiving end of which are mostly civilians, the Republika Srpska may well have to reconsider its further participation in peace talks,'' Karadzic wrote, using the formal name the Bosnian Serbs have adopted. NYT-09-12-95 2110EDT