NEW YORK, SEPT. 21 -- Who is the world's richest person? It depends on your choice in business magazines.

Fortune and Forbes are squaring off with rival lists of the world's billionaires that bear little resemblance to each other.

Forbes says the world's richest person is Yoshiaki Tsutsumi, a Japanese landlord who it says is worth $20 billion.

Fortune gives top honors to the "free-spending sultan of oil," Sultan Muda Hassanal Bolkiah Mu'izzadin Waddaulah of Brunei, who it says is worth $25 billion.

Fortune says Forbes rushed its list into print this week to beat Fortune to the newsstand by a week. Forbes admits it, but notes that it has been printing its own list of the 400 richest Americans since 1982.

"It was a bizarre move on their part to do this," Fortune spokesman Gary Belis said today of Forbes' decision to hurry up its list.

"If that somehow strikes Fortune as unfair, I cannot imagine the ground on which that protest would rest," responded Sheldon Zalaznick, Forbes' managing editor.

Calculating the wealth of billionaires seems to be more art than science, judging from the discrepancies between the two magazines' calculations.

Forbes' list is heavy with Japanese, while Fortune's is strong on Arab royalty and North Americans.

Tsutsumi, No. 1 on the Forbes list, is the 53-year-old head of Seibu Railway Group, which is Japan's biggest and richest landlord.

The empire consists of railways, more than 30 hotels, some 25 golf courses, ski resorts and other land.

Fortune, however, gives Tsutsumi credit for just $2.5 billion. Its own No. 1, the 41-year-old Sultan of Brunei, owns practically everything in the Delaware-sized country of Brunei on the island of Borneo.

Forbes says it disqualified the sultan from its list along with others like King Fahd of Saudi Arabia "since their power is political first and economic only secondarily."

Forbes' cover story includes only foreign billionaires, but the magazine issued a news release today with the names of the top 49 Americans on its annual Forbes 400 list, which will be in its Oct. 26 issue.

Only three individuals or families make the top 10 on both magazines' lists of combined U.S. and foreign billionaires.

They are Albert, Paul and Ralph Reichmann, Canadian real estate, newsprint and oil magnates; Kenneth Roy Thomson, a Canadian with interests in news media and real estate, and Sam Moore Walton, the discount retailing king from Bentonville, Ark.

The last big flare-up between business magazines came when Forbes remade the cover of its June 15 issue to resemble Business Week's in an effort to draw attention to its allegations that Business Week had copied its idea for reports on executive pay. Forbes List

Here is Forbes magazine's list of the 10 richest individuals or families in the world, including age, nationality and source of wealth.

Forbes grouped the billionaires in broad categories and did not offer specific estimates of wealth for each person.

More Than $15 Billion Yoshiaki Tsutsumi, 53, Japan, transportation, hotels.

More Than $10 Billion Taikichiro Mori, 83, Japan, property development.

More Than $5 Billion Brenninkmeyer family, West Germany and the Netherlands, retailing interests.

Yohachiro Iwasaki, 85, Japan, logging, property.

Shigeru Kobayashi, 60, Japan, real estate.

Hans and Gad Rausing, Sweden, liquid packaging.

Albert, Paul and Ralph Reichmann, Canada, real estate.

Kenneth Roy Thomson, 64, Canada, news media, oil.

Sam Moore Walton, 69, United States, discount retailing.

Haruhiko Yoshimoto, 63, Japan, real estate.

Fortune List

Here is Fortune magazine's list of the 11 richest individuals or families in the world in descending order of wealth, including age, nationality, estimated fortune and source of wealth.

Sultan Hassanal Bolkiah, 41, Brunei, $25 billion, oil, foreign investments.

King Fahd, 67, Saudi Arabia, $20 billion, oil.

Sam Moore Walton, 69, United States, $8.7 billion, discount retailing.

Samuel I. Newhouse Jr., 59, and Donald E. Newhouse, 58, United States, $7.5 billion, publishing, cable TV.

Queen Elizabeth II, 61, England, $7.4 billion, real estate, investments.

Kenneth Colin Irving, 88, Canada, $6 billion, oil, shipbuilding, forest products, newspapers.

Lester Crown, 62, United States, $5.7 billion, major stake in General Dynamics Corp., real estate, sports teams.

Kenneth Roy Thomson, 64, Canada, $5.5 billion, newspapers, retailing, real estate.

Forrest E. Mars Sr., 83, Forrest E. Mars Jr., 56, and John F. Mars, 52, United States, $5 billion, owners of Mars Inc.

Albert Reichmann, 58, Paul Reichmann, 56, and Ralph Reichmann, 53, Canada, $5 billion, Canada, real estate, newsprint, oil.

Sheik Jaber al Sabah, 61, Kuwait, $5 billion, oil.