The publisher of The Los Angeles Times warned yesterday that mounting public pressure to curb the nation's press will not subside until the news media adopt the same standard of ethics they expect from others.

Tom Johnson, in remarks prepared for delivery at the Fourth Annual Frank E. Gannett Lecture, said the current suspicion of the news media will persist "until we are willing to apply to ourselves the same standards we demand of others.

"We ought to admit it; there are too many violations of journalistic ethics . . . The fact is that many in our profession have been guilty of conflicts of interest, have been guilty of presenting outright fiction as fact, have been guilty of irresponsible and prejudicial reporting."

Johnson said the news media are quick to investigate conflicts of interest on the part of public officials and insist on public explanations for the actions of private corporations. Yet, he said, "We insist on greater access to government, to the courts, to the corporate board rooms. But too many of us apply a double standard when inquiries are made into the probity of our own actions."

Johnson warned that "we cannot have it both ways--pleading our rights under the First Amendment while opting to remain silent under the Fifth." He said the news media have too much power to try to exempt itself from accountability while demanding it of others.