From a church in Buffalo, to a hospital in New Jersey, to a school in Baltimore, the rumor is once again spreading out of control, whispered in offices, mailed in anonymous pamphlets, tacked on to bulletin boards.

The rumor, which has plagued Procter & Gamble for years, is that the nation's largest maker of household products -- from Crest toothpaste to Ivory Snow -- is in league with the devil.

Today, officials of the $13 billion conglomerate staged an extraordinary press conference in the gilded Louis XVI reception room of the Waldorf-Astoria here to "denounce false and malicious rumors associating the company with Satanism."

The company announced it has hired the detective agencies of Pinkerton Inc. and Wackenhut Corp. to track down the rumormongers. It has mailed more than 50,000 pieces of literature to schools, churches and media outlets, particularly in mid-Atlantic states, in an effort to contain the damage.

"We are prepared to take legal action against individuals or organizations spreading these stories," said P&G Senior Vice President W. Wallace Abbott. "This is so farfetched and unbelievable that it is often treated as a joke. . . . But this is a serious matter to us."

The company has set up a toll-free number (800-354-0508) to answer calls about the rumors, which are flooding its Cincinnati headquarters at a rate of more than 5,000 a month.

The recent outbreak of devil stories came just as the company thought it had finally quashed a similar plague of satanism rumors, which peaked in 1982. Then, P&G was getting as many as 15,000 calls and letters a month from consumers who had heard the company was giving part of its profits to the "Church of Satan."

The company launched a massive public relations effort at the time, enlisting religious leaders Billy Graham, Jerry Falwell and Archbishop Joseph Bernardin to denounce the rumor-fed boycott campaign aimed at Christians. P&G filed five lawsuits, all of them eventually settled, against people who spread the rumors, including an Atlanta television weatherman and four distributors of Amway products.

The rumor campaign is spread mostly through photocopied sheets or chain-letters featuring a drawing of the company's trademark, a man in the moon figure with 13 stars, which the letters claim is a symbol of the Church of Satan. The company logo, which is featured on all products, was registered as a trademark in 1882 and symbolizes the 13 colonies, according to P&G spokesmen.

A sample of a rumor sheet, which the company released today, declared that the president of Procter & Gamble had appeared on the Phil Donahue show and "stated that a large portion of Procter & Gamble's profit goes to the Church of Satan, also known as the Devil's Church."

The rumor sheet listed 45 products from Duncan Hines cookies to Tide Detergent and asserted, "All Procter and Gamble products now have the symbol of the Church of Satan on their labels. . . . Christians should always remember that if they buy any products with this symbol on them, YOU WILL BE TAKING PART IN THE SUPPORT OF THE CHURCH OF SATAN." The company is unable to measure any effect of the rumors on sales, it said.

Similar pamphlets allege that the P&G president had appeared on "Sixty Minutes" or the "Merv Griffin Show." No P&G official has ever appeared on either of the shows, a spokesman said.

However, since the new wave of rumors began about six months ago, starting in western New York and Pennsylvania and spreading to New Jersey, Maryland and Virginia, NBC's Donohue show has been flooded with calls.

In New Jersey, according to P&G spokeswoman Carol Taylor, a rumor sheet was posted on the bulletin board of Blue Cross and Blue Shield in Newark. The Archdiocese of Newark sent out a letter March 27 declaring: "It has recently come to our attention that a false rumor is being circulated by some groups in our parishes charging that the Procter & Gamble company has a connection with the 'Church of Satan' or devil-worship. We have been assured there is no truth to this rumor."

P&G officials said that while many of the 1982 rumors appear to have been spread by fundamentalist Christians, beginning in the South and Southwest, much of the recent activity is centered on Roman Catholic parishes, which are more populous in the Northeast. One Buffalo parish, St. John Kanty, reprinted the rumor pamphlet in its church bulletin last May, but retracted it the following week.

While P&G's spokesmen say no connection has been uncovered, the company was the target of a boycott in 1981 by the Coalition for Better Television and fundamentalist religious leaders who criticized the company's sponsorship of allegedly violent and profane television programs.