GUETERSLOH, WEST GERMANY -- Bertelsmann, a 150-year-old media conglomerate, catapulted into place as the world's largest media company late last year when it bought two companies that are American household names: Doubleday Books and RCA Records.

Those acquisitions -- added to an empire that includes Bantam Books, Brown Publishing Co., and Parents Magazine in the United States and dozens of companies in European publishing, printing, music, radio, television and film production -- give Bertelsmann gross revenue of more than $5.5 billion a year, outpacing its nearest rival in the media world, CBS Inc., by $1 billion.

Mark Woessner, Bertelsmann's chief executive, said in an interview that what distinguishes the company is not merely its size, but its corporate philosophy, which centers on producing highly motivated employes through strict decentralization and result-linked compensation.

"Some companies have an orientation towards their customers, or technology, or their product lines," the 49-year-old executive said.

"But in the media, there are literally hundreds of different products and branches. And our customer, who is he? Is he the German man who buys Stern {Germany's top-selling news magazine, 24 percent owned by Bertelsmann}, or the Brazilian teen-ager who buys a Whitney Houston LP, or the French woman who buys Femme Actuel? They are all very different. So we decided to concentrate on our employes.

"We decided to create an open and dialogue-intensive corporate culture. This generates creativity and motivation and brings out entrepreneurs on all levels.

"That is the true power and the success of Bertelsmann."

Four employe representatives sit on Bertelsmann's supervisory board and participate in all major strategic decisions. An employe profit-sharing scheme, involving nonvoting equity in the company, dates back to the 1950s.

Linking pay to results has made Bertelsmann one of the highest-paying companies in Germany. Woessner cited with pride a recent Der Spiegel article on the remuneration of top managers in West German industry. Of the top five companies, Bertelsmann was second (averaging $800,000 per senior executive in 1986), while Gruener and Jahr, Bertelsmann's magazine publishing subsidiary, was number five.

The company was founded by Carl Bertelsmann in 1835 as a publishing house specializing in religious publications. Ownership passed to the Mohn family in the 1920s when a Bertelsmann daughter married a minister named Mohn.

Reinhard Mohn retired as chief executive seven years ago but remains chairman of the supervisory board.

The Mohn family still owns 89 percent of the company's common stock.

Mohn initiated the company's rapid expansion in the 1950s, taking it into the highly profitable book club busireaching saturation point in West Germany, and Mohn went for diversification.

A major thrust into the United States came in the 1970s with the purchase of Bantam Books, a 50 percent stake in Arista Records, and a majority stake in Gruener and Jahr, which included American magazines Parents and Young Miss.

Despite its global reach, the company has stayed close to its roots.

Its headquarters remain in Guetersloh, a nearly inaccessible country town (the nearest major airport, Hannover, is an hour and a half away) on the north German plain.

The company still publishes religious books, and is closely involved in a wide range of social programs in Guetersloh, a town that seems to be chiefly composed of facilities for the manufacture and warehousing of Bertelsmann books, magazines, records and compact discs.

Unlike other leading media executives, Woessner keeps no penthouse apartments overlooking the Thames or the East River. Although he spends 60 percent of his time abroad -- relying heavily on the company's Falcon jet -- Woessner said he still lives in a house in Guetersloh "500 meters from the office and next door to Mr. Mohn."

Under Woessner's stewardship, the company has pursued a more controlled expansion.

In the 1970s, Bertelsmann grew sevenfold to a total revenue of $2.4 billion. For the 1980s, Woessner is aiming at only slightly more than doubling total revenue to some $6 billion.

His strategy calls for a geographic split of one third Germany, one third the rest of western Europe, and one third North America, a distribution effectively realized with last year's acquisitions.

In 1986, when Bertelsmann bought Doubleday for $475 million, analysts suggested the price was too high.

Woessner defended that price on the grounds of Doubleday's "strategic value" to Bertelsmann. Doubleday was a major player in its market with a recent history of low profits, ostensibly due to bad management.

Woessner integrated it with Bantam, under the control of Bantam President Alberto Vitale.

"With one acquisition, we became not only one of the biggest trade publishers in the world, but the largest book club group in the United States, the English-speaking world and the entire world," Woessner said. "It is a tremendous thing, and it gives us some important opportunities for the 1990s."

Not unlike Doubleday, RCA Records was a once-great name in its industry that by the 1970s appeared to have lost direction and profitability.

The worldwide Bertelsmann Music Group (BMG), headquartered in New York, is now under the overall control of Bertelsmann executive board member and close Woessner confidant Michael Dornemann.

Dornemann, like Vitale, is what Woessner considers a classic Bertelsmann "entrepreneur": a professional manager with a proven track record in more than one industry and in more than one country.

Dornemann is the first member of Bertelsmann's executive board to be based outside Germany.

Woessner said the reorganized BMG was producing good results faster than he had expected at the time of the takeover.

"We will expand and develop the music business, but not for any price," said Woessner. "Slowly and step by step."

Woessner emphasized that every one of the group's American operations would be 90 percent or more staffed by Americans.

"Twice a year I go to the U.S. to look for MBAs for our group," he said.

One of the more remarkable aspects of Bertelsmann is the political and editorial freedom it allows its editors.

European media companies are notorious for their strong political lines. Springer in West Germany, Hersant in France, and publisher Rupert Murdoch in Britain impose a conservative line on all their publications, while British publisher Robert Maxwell insists that all his papers support socialists.

Stern, like Bertelsmann's first newspaper venture, the Hamburger Morgenpost, has a liberal to slightly left tinge, while the company's business magazine Capital is firmly on the right. Woessner said that editorial independence is a vital element in Bertelsmann's creed of decentralization.

"A monolithic media company can be dangerous," he said. "A decent, pluralistic company is never a problem for society."

Woessner said the next three years will be devoted to digesting the recent acquisitions.

He foresees more growth in the 1990s: a South American division as the fourth leg of its empire, with perhaps joint corporate headquarters in New York and Guetersloh.

"But to be the biggest is not our goal," he said.

"To make very good products and contribute excellent things to society, and to earn so much money that we can continue to develop these businesses, that is what counts."