The Lebanese Army chief of staff and 16 other high-ranking officers today issued an appeal for Army neutrality and warned against involving it in internal disputes or the defense of individuals -- an indirect reference to President Amin Gemayel.

Maj. Gen. Mahmoud Thai Abu Dergham, the Druze chief of staff of the armed forces and vice president of a six-member military council, made an unusual public appearance with a dozen senior officers to issue the appeal.

Any digression from Army neutrality or unity would spell disaster, the chief of staff warned.

The plea coincided with press reports that Lebanese Army units have been removed from the volatile Green Line separating Beirut's Moslem and Christian sectors and sent to reinforce strategic spots in Christian enclaves.

An escalation of fighting along the Green Line this morning led to a four-hour closure of key access routes linking the Christian and Moslem sectors of the capital.

Sectarian divisions and disunity will undermine the Army's credibility, Abu Dergham said, "and the last hope for the Lebanese will be lost. The Army will turn into warring fragments . . . defending individuals, parts of the homeland or artificial entities at the expense of the people."

Three of the officers signing the petition today were Christian; the others were Moslem.

Beirut newspapers reported that Army soldiers withdrawn from the Green Line on the Christian side of Beirut were sent to reinforce positions around Gemayel's summer and winter palaces at Bikfaya and the Beirut suburb of Baabda.

Additional units were dispatched three weeks ago to Douar, above Bikfaya, Gemayel's hometown, to shield it from a possible Syrian-backed offensive by leftist and Moslem militias.

Other battalions have been rotated to beef up Army defenses at the strategic Suq al Gharb axis, the last Army front line facing Druze militias above the presidential palace in Baabda.

The 44-year-old Christian Maronite president has come under fire from Moslem opponents for his reluctance to acquiesce to a Syrian-negotiated pact among Lebanese militia groups and has resisted mounting pressure to resign.

The 8th, 5th and 10th brigades, mostly Christian and assigned to defend Bikfaya and Suq al Gharb, are the Army's best-trained and equipped brigades.

Syria has given no sign that it will get directly involved in a show of force aimed at unseating Gemayel.