Meet His Royal Highness Prince al-Waleed bin Talal bin Abdulaziz al-Saud, 37, nephew of King Fahd and a scion of the Saudi royal family. Three years ago he stunned Wall Street by putting $590 million into Citicorp when its stock was at a low and some in the industry thought the bank might fail. Smart move: in 15 months, his 10 percent stake doubled in value. Now the prince some call charming has placed another big bet, agreeing last week to invest up to half a billion dollars in Disney’s troubled theme park outside Paris. Could the payoff be as rich as last time’s? ““I don’t give quotes,’’ says the prince. ““But you want one, here’s one: “Four years ago people were saying the investment in Citicorp did not look good. It was fantastic. Disney will be the same’.''

If so, it would be a daring score. Euro Disney’s stock (49 percent owned by Walt Disney Co.) has tanked to one fifth its high; financial buzzards have been circling for months. If al-Waleed’s cash drives them away and helps put the park on its feet, the prince could become the Saudi Warren Buffett. Already he’s a bottom-fisher of some repute. Those who know him say he’s all business. ““He’s a wheeler-dealer on a gigantic scale,’’ says an acquaintance in London. The prince’s move into Disney, as this man tells it, was no idle folly of a dissolute Saudi prince, a place to take goat herds of kids and say, ““All this is yours.’’ No, this guy is ““intense, driven, even a bit manic, a very serious investor.’’ His office in Riyadh resembles more a high-tech pirate’s ““den’’ than a corporate headquarters. Lots of dark marble, wood and heavy desks, surround-ed by television screens, video consoles and communications gear. The prince sits in the gloom, fiddling with his worry beads, monitoring Reuters and the world financial news. Says this source: we will hear more of Prince al-Waleed.

That seems a safe bet. Years ago the prince said he wanted to be worth $5 billion by 1998. With more than $4 billion, he’s nearly there. Among the many-thousanded royal family, he’s a luminary, son of the 23d son of Abdulaziz, the father of postfeudal Saudi Arabia. Raised in Beirut and Riyadh, educated at Menlo College in California and Syracuse University, where he studied business and social science, the skinny and upper-five-footish Royal Highness is, as his official bio puts it, ““the prototype of the emerging Saudi businessman, highly educated and intellectually and spiritually committed to the development of his country.’’ Legend has it that his father (a royal black sheep who liked fast cars and was dubbed the ““Pink Prince’’ for his democratic sympathies) kicked him out of the family palace with only $15,000 and a 130-room, 30-bath bungalow to his name. Seek your fortune, the patriarch ordered, and so the young prince did. He reputedly blew the $15,000 in two weeks, then took out a fat mortgage on his house (from, you guessed it, Citibank) and started a construction company called Kingdom Establishment for Trading & Contracting.

That was 15 years ago. From then on, it was rags to riches, Saudi style. Cash in on the family name to win all sorts of contracts for hotels, office high-rises and military projects. Buy your own bank, United Saudi Commercial Bank in Riyadh, clean it up and be named chairman. Then write humongous checks that no financially troubled institution (such as Citicorp in 1991) could turn down, and watch the money roll in.

Riches are their own reward, at least for Prince al-Waleed. His stock in Citicorp has grown to some $1.6 billion, not counting the $318 million he reaped last year by selling 12 million shares. Among the prince’s more visible holdings: 11 percent of Saks Fifth Avenue, a chain of hotels and supermarkets and a big chunk of the new Arab Radio and Television network, broadcasting four satellite channels around the Middle East. He won’t talk about that pesky royal decree banning satellite dishes in the kingdom. Nor does he discuss his recent foray into France (where he spends a good part of the year floating, off the Riviera, aboard his 264-foot yacht, the former Trump Princess) to join with the giant Sofitel hotel group in bidding for the Meridien luxury hotel chain, owned by Air France.

The prince’s play for Disney puzzles some people. The theme park is losing money not for lack of investment, doubters say, but because Europeans simply aren’t coming in large enough numbers or spending enough money. ““I’m surprised anyone would invest,’’ says one Los Angeles attorney knowledgeable about the deal. But Disney officials say it makes sense for both parties. The prince could give Disney a boost by building, as he plans to do, a $100 million convention center at the park, drawing in conventioneers and their families, who would not otherwise come. Meanwhile, al-Waleed seems to be betting that France’s economy, mired in recession, will soon rebound. Indeed, there are signs that he may have timed this deal just right, says Jessica Reif at Oppenheimer & Co. ““It’s a very intelligent investment. He’s buying at the bottom.’’ Chalk up another one for the prince?