BETHLEHEM, Occupied West Bank (AP) _ Moderate Palestinian leaders on Tuesday applauded Prime Minister Shimon Peres' trip to Morocco and said they hoped it signaled a resumption of Middle East peace efforts.

But the surprise visit was denounced by supporters of Yasser Arafat in the Israeli-occupied West Bank and they vowed to fight any proposals that exclude the Palestine Liberation Organization.

The summit with Morocco's King Hassan II seemed certain to aggravate differences among PLO factions and between pro-Jordanian moderates and Palestinian nationalists.

Tensions have heightened in the territories captured by Israel in the 1967 Middle East War in the two weeks since Jordan's King Hussein shut 25 Amman offices of Arafat's Al Fatah wing of the PLO.

Palestinian nationalists expressed concern that by meeting Peres the Moroccan monarch was throwing more Arab weight behind Hussein's anti-PLO crackdown.

''If that's what this visit does we will strike and demonstrate and do everything to oppose it,'' said Mustafa Kawaja, 20, a student at Bethlehem University.

Some Arafat supporters praised Peres' move. Hanna Siniora, editor of the East Jerusalem-published Al Fajr daily, called it ''a bold step,'' and compared it to the late Egyptian President Anwar Sadat's historic trip to Jerusalem in 1977 that paved the way for Israel's first peace treaty with an Arab country.

''But in order to achieve peace in the region, the Palestinian people and the PLO must be represented,'' said Siniora.

Mayor Elias Freij of Bethlehem, who endorses Hussein's policies, said he believed ''it's a very important trip. I hope the two leaders can agree on getting the peace process started on the basis of a territory-for-p eace exchange.''

''With all the bad news we have in this area, this meeting could produce something. Let us cross our fingers and wish them good luck,'' Freij added.

News of Peres' trip dominated conversation on Bethlehem University campus, a stronghold of Palestinian nationalism. Students said they feared Peres' trip, like Sadat's 1977 journey, could lead to what they called a sellout of Palestinian rights.

Many of the 1.4 million Palestinians in the West Bank and Gaza Strip accused Sadat of being a traitor for failing to secure Palestinian statehood in the 1979 Israel-Egypt peace treaty.

''We are against all of them - Jordan, Morocco, Saudi Arabia - all those who are trying to replace the PLO,'' said student council chairman Ahmad Jardat, 25, of Hebron. ''There will be no peace without the PLO.''