A night of heavy shelling that intensified this morning, striking deep into residential areas, postponed a symbolic encounter between Lebanon's highest Moslem and Christian religious authorities today.

Routine clashes along Beirut's traditional confrontation lines yesterday afternoon deteriorated rapidly into the fiercest bombardment in two months of the Kesrouan hills, the countryside around the presidential palace in the Christian heartland, and Beirut's Moslem Shiite suburbs.

The death toll rose to 40 today, with more than 120 wounded. The Barbir Hospital received seven direct hits and eight persons were killed instantly in the Credit Libanais Bank in Moslem-controlled west Beirut. Most of the casualties occurred in the overpopulated Shiite outskirts of Beirut.

A scheduled visit by the newly appointed Christian Maronite patriarch, Nasrallah Sfeir, to the Sunni mufti of the republic, Sheik Hassan Khaled, in west Beirut was cancelled. The encounter, planned in response to a courtesy call by Khaled last month, had been deemed significant as a potential bridge between the two communities.

It would have been the first trip by a Maronite patriarch, Lebanon's most senior Christian religious figure, to the Moslem half of the capital in nine years. Khaled's visit on April 28 had been scoffed at by Moslem factions closely allied with Syria, such as the Shiite Amal movement.

"I would hate to think that the intention behind the outburst was aimed at postponing the visit [by Sfeir], which was meant to create a new climate and clear the black clouds hanging over Lebanon," Khaled said.

Shells slammed around the Maronite patriarch's hilltop headquarters seven miles north of Beirut. One Lebanese soldier was among the fatalities, but the remainder all were civilians.

Schools in Christian and Moslem areas sent students home today out of fear of continued fighting. The Amal movement charged tonight that the Lebanese Army and the Christian militias were to blame for the carnage.

A group of Christian politicians and militia chiefs is promoting a draft plan for reforms and an end to Lebanon's 11-year-old civil war. Gemayel, a Christian Maronite, has distanced himself from the plan and has yet to announce his position.