There was no press release to mark the passing of one of America's most innovative and successful businessmen -- no detailed list of his accomplishments, no lovingly crafted eulogy.

Even in death, Forrest Mars Sr. tried to remain completely anonymous. The 95-year-old patriarch of Mars Inc., the $20 billion multinational candy and pet food enterprise based in McLean, was an elusive and enigmatic figure throughout his life, shunning photographers, rebuffing journalists and keeping himself and his company out of the spotlight.

Mars's insistence on anonymity at times reached comic levels: On Friday, following his death from natural causes Thursday night, a spokesperson for the M&M/Mars candy division refused even to admit that Forrest Mars had worked for the firm.

Not only had Forrest worked for Mars, he was its inspiration, architect and builder -- the man behind such beloved brands as M&M's, Snickers and Milky Way; Uncle Ben's rice; and Pedigree brand pet foods.

While these brands conjure up instant images in consumers' minds, there is no such picture of billionaire Forrest Mars Sr. himself. Though routinely cited as one of the most successful entrepreneurs in America, he was not a household figure like Sam Walton, Warren Buffett or Bill Gates. Nor did he want to be. Forrest Mars never cared about the public's love, respect or admiration; he just wanted every dollar of its business. And he pursued that goal in a way entirely his own.

At a time when most candy companies were small, family-owned firms run in haphazard fashion, Forrest Mars brought the mind of a scientist to his task, rationalizing and systematizing the management of his companies. He drew on the nascent field of operations management to develop, with mathematical precision, his managers' goals, schedules and rewards. To this day, his precepts, distilled into a 30-page manual, govern the company's every move.

To get the best people he paid salaries well in excess of his competitors' but he tied pay directly to corporate performance. Mars employees -- called "associates" -- could earn as much as 15 weeks' extra salary in a good year. But associates -- including Mars -- were also required to punch a time clock, and failure to arrive promptly resulted in a 10 percent cut in your monthly pay.

Forrest Mars also eschewed bureaucracy. He forbade lengthy memos, meetings and fancy corporate perks, and he ran his entire operation with just a handful of managers. Even today, the company's 30,000-person work force reports to a headquarters with just 50 people -- and no private offices.

The company's success was equally driven by Mars's fanatical commitment to quality. He railed against "incremental degradation," the way companies would gradually cheapen products by substituting lower-cost ingredients. He was the first candy maker to scientifically measure the quality of his products. Each Snickers bar, for example, was required to contain 15 peanuts -- no more and no less. The ratio of nougat to chocolate had to be identical in every Milky Way of a given size.

To meet such exacting standards required the most advanced equipment, and Mars would often modify his machinery to achieve efficiencies unheard of elsewhere in the industry.

Mars was the first to use computers to monitor the quality of his product, and even today the company's plants, more than 40 worldwide, are the most advanced in the business.

Every eight hours, more than 100 million M&Ms roll off the company's production lines in Hackettstown, N.J. At the end of the line sit dozens of industrial-sized laundry bins, each one filled to the top with rejected M&Ms -- those on which the color isn't perfect or the "m" missed its mark. These misfits are eventually ground up and returned to the mix, a necessary part of the M&M formula.

Mars's management style presaged many "modern" business practices -- such as total quality management and worker empower- ment -- although without such fancy labels. He gave every associate a sense of ownership in the company. He set the goals, then left it to associates to make their own decisions, and rewarded them for the company's success. Every factory worker had the authority to stop the production line if they noticed something awry -- and they would be fired on the spot if they didn't do just that.

He was a different breed indeed, one long since thought to be extinct: a man who measured himself by accomplishments, not popularity. In these days of celebrity chief executives media frenzy and information overload, Mars was, remarkably, able to elude the paparazzi and confidently ignore America's insatiable appetite for heroes and icons.

In the gated Miami condominium community where Mars spent most of the past five years, his neighbors knew him only as the "nice old man" with the sweet tooth -- an ironic image for an entrepreneurial genius whose life was characterized by driving ambition and a volatile temper.

"I'm not a candymaker. I'm empire minded," Forrest Mars often said.

As early as the 1920s, Mars envisioned a global business strategy. When he failed to convince his father, Frank C. Mars, to expand sales of his Milky Way bar into Canada, Forrest left the company and struck out on his own.

He founded Food Manufacturers Inc., just outside of London, and turned it into one of Europe's leading candy manufacturers. While in England, he oversaw the development of an entirely new industry, canned pet foods, building on potential he saw in a small canning company.

Upon his return to the United States in 1939, he created a new candy, M&M's, that would ultimately transform him into a multibillionaire, and one of the richest men in the world.

And he purchased a newly developed, easy-to-cook, more nutritious kind of rice that he marketed as "Uncle Ben's." But his success depended less on these particular products than on his values and unique management philosophy.

His closest managers admired his cunning business sense and unwavering dedication to the quality of his products, but they also feared Mars's uncontrollable temper. An improperly wrapped candy bar would throw him into a rage; a pinhole in the coating on a Snickers bar would result in a 30-minute tirade.

"Forrest would rant and rave about how we represented the customer inside the factory," said Mark Cross, who worked for Mars in England in the early days. "He was on you like a mosquito if he suspected you weren't doing your job right."

His unique style grew out of careful study of other businesses but was molded by his exacting personality. Those who worked closely with Forrest said he couldn't have run his company any other way.

"It was in his blood," said Duke Vance, one of Mars's top managers. "He never once thought of doing it differently."

Mars delegated tremendous responsibility, in part because he was much more interested in building businesses than in managing them. After putting in place the management systems, he spent his time searching for new products, new manufacturing techniques and ways to improve quality and efficiency.

Those who worked for him described him as a dictator, and much more: He was an explorer, a conqueror, and he was never satisfied.

Perhaps the most remarkable example of his restlessness occurred in 1973, when the 69-year-old Mars retired from the company he had built, turning it over to his sons, Forrest Jr. and John. Forrest Sr. was ready for new challenges.

With a carefully chosen group of managers, Forrest Mars went on to build a new business in Las Vegas. Called Ethel M Candies, it produces liqueur-filled chocolates and fulfilled Forrest's lifelong dream of producing top-quality, handmade chocolates. (Ethel M is now part of Mars Inc.) He also devoted himself to the breeding of racehorses and cattle, trying, in his unique way, to produce faster horses and leaner beef. He even expanded his interests to horticulture, inventing a new formula for plant food that is sold in Europe.

Though a 1994 stroke left him confined to a wheelchair, he remained mentally sharp, and continued to cast a shadow over the company. Associates say Mars never stopped harassing his sons, critiquing their management decisions and offering often unwelcome advice.

But his greatest concern was whether the company could survive into another generation of family leadership. The depth of this concern led him, in 1992, to meet with Nestle Chairman Helmut Maucher to discuss a buyout. Officially, Nestle and Mars deny these talks ever took place, but family members say Mars approached Maucher because he was convinced that the company would be endangered by the difficulties of sharing ownership and control among his 10 grandchildren.

At any given time, as many as a half-dozen of these grandchildren are likely to be working for the company. But there is no clear-cut successor. If Forrest's children have made plans for an orderly transition, they have kept them very close to the vest, not even sharing them with the company's most senior executives, some of whom have left Mars, citing the uncertainty.

This tenuous situation has grown only more complex with recent events. Forrest Jr., 68, quietly retired from the firm in April, leaving his brother, John, as sole president and CEO. This change has increased tension in the executive ranks and made many employees nervous about the future.

Forrest Mars's death can only heighten such unease. Under the terms of the family trusts that hold the company's shares, Forrest Sr. held veto power over any sale of Mars Inc. -- a fact that may have kept his sons from pursuing various possibilities.

Now, however, it is anybody's guess whether this most successful of private firms will stay in the family. Those closest to the brothers believe it is likely that Mars, or pieces of it, will be sold before John's retirement. It is easy to identify companies that might be interested in acquiring Mars assets, given its dominant position (rivaled only by Hershey Foods Inc.) in the U.S. candy market and its global leadership in both candy and pet food.

Some company insiders go so far as to predict Mars will go public, a prospect that may seem inconsistent with the company's long-standing insistence on secrecy. But those who knew Forrest Sr. knew that his aversion to publicity was always subordinate to the needs of the business. What he truly wanted was whatever would make his company a success.

As Forrest Jr. put it in a rare public appearance in 1988, the ability to be secretive "is one of the finest benefits of having a private company. Privacy at times today seems a relic of the non-media past, but it is a legal right -- morally and ethically proper and even desirable -- and a key to healthy, normal living. . . . It allows us to do the very best we can, the very best we know how, and to do so without being concerned with self-aggrandizement," he told a group of business students at Duke University.

In keeping with that tradition, the family remains silent, refusing to say anything at all about the business, their father or the future.

Joel Glenn Brenner is a former Washington Post reporter and the author of "The Emperors of Chocolate: Inside the Secret World of Hershey and Mars" (Random House, 1999).

More than Chocolate

Forrest Mars Sr. built Mars Inc. into a worldwide confectionary giant. The company is best known for its candy...

Dove

Milky Way

M&M

Skittles

Snickers

Starburst

Three Musketeers

Twix

...but it also produces other common products.

Combos

Kal Kan dog food

Kudos granola bars

Pedigree dog food

Whiskas cat food

Uncle Ben's rice

CAPTION: Through the force of his personality, Forrest Mars Sr. built Mars Inc. into a $20 billion global business. "I'm empire minded," he often said. (1984 photo)