The Brazilian-born billionaire's skirmishes with Mr. Zuckerberg over the future of Facebook were dramatized in the 2010 film "The Social Network," which portrayed Mr. Saverin as a naive entrepreneur.
Mr. Saverin was squeezed out of Facebook early on, and found his stake in the Internet juggernaut diluted to less than 10% from 34%. Today, after more dilution and sales of some of his shares, his stake is about 2%, according to a person familiar with the matter.
But 2% can go a long way, given that Facebook filed documents Thursday to go public with a valuation of up to $96 billion. It can go especially far in Singapore, a financial center better known for banning the sale of chewing gum than for a thriving technology scene.
Since his arrival in 2009, the 30-year-old Mr. Saverin has attracted intense interest here. Singaporeans avidly track his nocturnal social habits. Many hoped he would fund local tech start-ups, but so far his local investments, which include a cosmetics firm, have been limited.
Mr. Saverin is regularly spotted lounging with models and wealthy friends at local night clubs, racking up tens of thousands of dollars in bar tabs by ordering bottles of Cristal Champagne and Belvedere vodka, according to people present on these occasions. He drives a Bentley, his friends say, wears expensive jackets and lives in one of Singapore's priciest penthouse apartments.
Mr. Saverin didn't respond to multiple interview requests.
Other Facebook founders have followed a somewhat different path, at least publicly. Mr. Zuckerberg is most often seen in public walking his dog, and continues to wear his signature zip-up hoodies and drive an Acura. Fellow Facebook co-founder Dustin Moskovitz launched a work-collaboration start-up and has pledged, along with Mr. Zuckerberg, to give half his wealth to charity. Chris Hughes worked for Barack Obama's presidential campaign and recently bought a controlling stake in the New Republic magazine.
In Singapore, Mr. Saverin is a Kardashian-like figure, with scores of fans hoping for a sighting. Local websites have set up forums with threads entitled "Where does one meet Eduardo Saverin in Singapore?" Bloggers and journalists have written long posts after spending mere seconds with the billionaire.
Singapore's Tatler, a society magazine, added him to its "300 List," which celebrates the biggest power players here, including a shipping-container magnate. Mr. Saverin's Facebook posts, which range from updates on his investment company to pictures from travels across the region and nostalgic reflections on Facebook itself, get thousands of "likes" and comments, and hundreds leave messages hoping to meet the man in person.
"Eduardo, I need to talk to you sir. For real! Hit me up," said one Facebook user on Mr. Saverin's public Facebook page.
Mr. Saverin, who hails from a wealthy Brazilian family, has never fully explained why he moved to Singapore, but he has mentioned its strategic location and business-friendly environment in his few public appearances. Those close to him say he once stopped off here while traveling in Asia and liked it.
The city-state has tried to become an Internet hub, with limited success. But it is increasingly known as a playground for the rich, with the world's highest percentage of millionaires, and its glitzy night life.
Its tightly controlled local media is largely free of the tabloids that hound celebrities in places like the U.S. Local press reports have referred to Mr. Saverin as a "Facebook legend," "nice and humble" and "generous" when spending on his friends in nightclubs. Night-life magazines refer to him as one of "Singapore's hottest partygoers."
Though Mr. Saverin speaks at select conferences, he is extremely media-shy, often declining to talk to the media.
Mr. Saverin has invested in a number of start-ups, mainly back in the U.S., including Shopsavvy, a price-comparison mobile application; Qwiki, a multimedia video website; and Jumio, a mobile-payments start-up. He put more than $6.5 million each into those companies.
Mr. Saverin's most notable local investment is in Singapore-based Anideo, headed chiefly by Andrew Solimine, a longtime friend. The company has developed a video-streaming application, Denso, that specializes in selecting videos based on a user's personal taste.
Although many of his investments are viewed as promising, none has been nearly as successful as Facebook, to the disappointment of local techies who had hoped his presence would kick-start the country's entrepreneurial scene.
"Eduardo doesn't invest in much. He doesn't invest in Singapore companies," grouses John Fearon, CEO of Singapore start-ups dropmysite.com and dropmyemail.com that back up emails and website content. He says he didn't ask Mr. Saverin for money. "He doesn't set up his stall and say, come to me for investment."
Some of Mr. Saverin's other projects have been less conventional, including a cosmetics line launched in 2010 by Rachel Kum, Singapore's 2009 entry in the Miss Universe pageant. Mr. Saverin invested an undisclosed sum in the company, according to people familiar with the matter. He appeared in a TV news report about the line's debut in footage showing him flanked by models.
Government and corporate leaders routinely invite him to speak at conferences and other functions, but he doesn't have a great record of showing up, though, organizers say.
Mr. Saverin was invited to judge pitches for start-ups last June at Echelon 2011, a conference sponsored by Microsoft Corp., Amazon.com Inc. and others. "It was exciting because "The Social Network" movie had come out, [and] there was a buzz about him being in Singapore," said Joon Ian Wong, who then worked for E27, the event's organizer. "Start-ups wanted to…see Saverin in the flesh."
But hours before he was due onstage, Mr. Saverin canceled via text message, saying he wasn't well. People familiar with the matter say he has canceled other appearances at the 11th hour.
None of that has dimmed his star in Singapore. Mr. Saverin's activities are good for the city-state, says Ash Singh, an investor and the CEO behind "Angel's Gate," an Asia-based reality-TV series focusing on investment and entrepreneurship. "Is Eduardo an entrepreneur? I don't know," he says. "But he did well for himself, he has come here, there is a movie about him, and people aspire to be like him."
Sam Holmes and Geoffrey A. Fowler contributed to this article.