NORFOLK -- Blaming scandals at other television ministries, Marion G. (Pat) Robertson said yesterday that a drop in donations has forced him to lay off 470 employes -- 200 of them full-time workers -- at his Christian Broadcasting Network. "We are laying off godly, dedicated, wonderful people . . . because we just don't have the money to pay their salaries," said Robertson.

Robertson, who is weighing a bid for the 1988 Republican presidential nomination, said his Virginia Beach-based network has been hurt by scandals at the PTL ministry, formerly run by Jim and Tammy Bakker in Fort Mill, S.C.

"We have probably the finest forecasting and budgeting processes in the evangelical world, but it is impossible to forecast an atomic explosion," Robertson said on his flagship television program, "The 700 Club." "In the history of American Christianity we have never seen anything like this. That scandal has hit the evangelical world like a bombshell."

He also blamed the Rev. Oral Roberts, who had said he would die this spring if he did not receive donations.

"The direct result of the two things that have been going on in the evangelical world since the first of this year have cost us through May $12 million in lost revenue," he said. He projected a $28 million loss by the end of the year.

A recent Gallup poll showed that half of all donors to religious radio and television programs have stopped giving, Robertson said.

His network employed 2,100 people on an annual budget of $177 million as of March, said Gailon Totheroh, a CBN spokesman. Robertson laid off 41 employes and sold three television stations to cut costs in April 1986.

Those who were laid off yesterday, apart from the full-time employes, were 300 part-time or temporary workers, said Tim Robertson, Pat Robertson's son and the network's president.

Pat Robertson also announced that the network is dropping its toll-free telephone line and will scale back its Operation Blessing, which distributes money for charity.

With the announcement came a plea for more donations.

"This is an emergency and we need help now," Pat Robertson said. "In 25 years, I've never been someone to cry wolf."

But he predicted that the network would emerge from the crisis stronger than ever.

"I am convinced that God is going to do a miracle in the midst of all of this," he said.

Robertson mentioned that his frequent absences from "The 700 Club" for political travels may have hurt donations, but he placed most of the blame for his troubles on the Bakkers and Roberts.

Jim Bakker resigned from PTL in March after confessing adultery with a church secretary and payment of hush money to silence her. Since then, he has been defrocked by his denomination, the Assemblies of God, accused of homosexual encounters and is under investigation by the Internal Revenue Service, the Justice Department and postal officials for alleged financial improprieties.

Robertson read comments during yesterday's program from two callers, one of whom said "my husband will not allow me to watch TV ministries because of PTL." Another viewer, Robertson said, told CBN, "I have given to the PTL for years, and I'm very disappointed and cannot give until I get over this hurt."

At least one CBN employe blamed the network's fiscal crisis on Robertson's presidential ambitions.

"We need him in the White House, but it may cost CBN to do it. People are giving him money for that instead of for us," the employe, who was not identified, told The Virginian-Pilot.

A University of Virginia sociologist who studies the evangelical movement said Robertson probably is right to blame the Bakkers and Roberts.

"These controversies or these scandals have called into question the integrity of the personalities leading these businesses, as well as raised very serious questions about the way these businesses are conducted," said James Davison Hunter, an assistant professor of sociology at U-Va. "Consequently, it's going to affect everyone.

"Once this becomes a dead issue and a matter of speculation and interpretation on the part of historians and sociologists, at that point I think there's a good chance that these industries, or these ministries, will rebound," Hunter said.

In the meantime, Robertson can do little to stop the slide, Hunter said. "He'll just have to ride it out."