The wedding was the first for Craft, 34, and the fourth for Ellison, 59, CEO of Oracle, the world's No. 2 software-maker.

The couple married on Dec. 18 at Ellison's 45-acre Japanese-style compound in Woodside. The ceremony was conducted beside a waterfall by Rep. Tom Lantos, D-San Mateo, a close friend of the couple, and attended by Ellison's best friend, Apple computer co-founder Steve Jobs, and his wife, Laurene. Jobs did double duty as the wedding photographer.

"Was it spur-of-the-moment? Yes and no,'' Ellison said in a telephone interview yesterday. "We've talked about getting married but never set a date. The timing just seemed right.''

Craft said Ellison was naturally skittish about delving into another marriage after three tries.

"We reached a point where we knew we would not be breaking up whether we got married or not, so it seemed to make it easier by just getting married,'' she said by phone from one of the couple's other homes, in Atherton.

Ellison referred a question about whether they had signed a prenuptial agreement to Craft, who declined to answer, saying the matter was private.

Craft's third novel, "Man Trouble,'' is scheduled for release in May. The plot revolves around a college professor and romance novelist who goes undercover to seduce a playboy billionaire and turn him into a family man.

Craft said the novel was not directly autobiographical but was inspired by a New York newspaper story that alleged she had been invented by Ellison's public relations department to soften his image.

News of the wedding, which surprised Ellison associates inside and outside Oracle, comes one day after the founder of the Redwood Shores-based company shed one of his titles, the job of chairman. Ellison retains the title of chief executive officer and said he would not step back at all from running the company.

"I expect, if anything, to spend more time at Oracle,'' he said Tuesday.

The manner in which the ceremony took place showed a quieter side to the sometimes-flashy Ellison, who is known for his aggressive business manner. He also has a zeal for high-stakes sailboat racing, as a participant in the America's Cup, and for flying jet fighters. After losing the America's Cup race in New Zealand last year, he challenged the winner, Swiss pharmaceutical giant Ernesto Bertarelli, to a rematch on San Francisco Bay. Ellison's Oracle BMW team emerged victorious in September over the Swiss Alinghi team for the Moet Cup.

The couple spent their honeymoon in the Caribbean at the Grenadine Islands and at Mustique aboard Katana, one of Ellison's two yachts. Ellison owns homes in San Francisco's Pacific Heights, in Atherton and in Malibu, as well as the compound in Woodside, which has been under construction for 10 years. The couple plan to move into the home in Woodside in the spring.

No official wedding photo was available because the photographers -- Jobs and Ellison's son, David -- had not finished preparing them for the photo album yet, Ellison said.

The couple met in a restaurant in San Francisco in 1995. Craft, a native of Pittsburgh, majored in anthropology at Oberlin College, studied archaeology at American University in Cairo and lived in Kenya for a year.

Ellison is the ninth-wealthiest man in America and one of the richest in the world, with $18 billion, according to a recent listing by Forbes magazine.

Shares of Oracle fell 2 percent to $14.36 Tuesday. If anything caused the stock to fall, it was likely uncertainty about the management changes announced Monday, which included leading executive Jeff Henley's giving up his job as chief financial officer to become chairman.

Financial analysts were unruffled at the news of Ellison's marriage.

"He's been fairly obsessed with his company for over 20 years," said Patrick Walravens, an analyst with JMP Securities. "I don't see this changing that."

Business and matrimony have not mixed smoothly for the billionaire business leader in the past. Ellison's third marriage was to Barbara Boothe, the mother of his two children, in the early days of Oracle, and the union was a rocky one, said Mike Wilson, an Ellison biographer.

"Oracle was in its 100 percent-a-year growth phase in those days, and one of the many issues in that relationship, to hear Barbara tell it, was he was mostly interested in being in charge of Oracle, and not in being in a relationship," said Wilson, now the features editor at the St. Petersburg Times. Wilson's book, "The Difference Between God and Larry Ellison (God Doesn't Think He's Larry Ellison)," was recently re-issued in paperback.

Ellison is known to have used a prenuptial agreement in the past; in fact, his marriage to Boothe was nearly called off when Ellison presented her with an 11-page prenuptial agreement just hours before they were to walk down the aisle, according to Wilson's book. Boothe and Ellison were divorced in 1986, less than three years after they wed.

But in those days, Ellison was micromanaging the start-up, Wilson said. These days, the tech titan may have more time for marriage.

"My impression is that he's scaled back a lot from the day-to-day operating; he recognizes that he's more of a spiritual leader of Oracle and company visionary," Wilson said.

Ellison also was married to Adda Quinn (1967 to 1974) and Nancy Wheeler (1977 to 1978). Oracle was founded in 1977.

Management psychologist Gene Morrissy says a CEO's marriage is usually good news for a company.

"If there is an impact, in the main it would be a positive one, in terms of the person's overall demeanor and state of mind," said Morrissy, who works for Chicago management psychology firm RHR International. "Now if it's a fractious marital situation, all bets are off."

Ellison said he is better at his job when his primary personal relationship is working. "When I'm happy, I'm more focused, and I'm a much more effective leader at Oracle," he said. "And I'm very happy.''

Also attending the wedding were Ellison's children from a previous marriage, Megan, 17, and David, 21; Craft's sister, Kira Craft, a fashion designer in London; and Lantos' wife, Annette.

Melanie Craft's latest work, "Man Trouble," will be published by Warner Books in May. And the plot has an eerily familiar ring to it: It's about a romance novelist who seduces a billionaire businessman.

In this excerpt, published as an addendum to Craft's last book, "Trust Me, " a journalist friend, Carter, is trying to persuade the heroine, Molly, to seduce the billionaire to help land a big interview:

"Out with it," she said. "What's the project?"

"Okay," he said. He put down the cup and stared meaningfully at her. "Two words. Jake Berenger."

Molly nodded. "And?"

Her lack of reaction had clearly disappointed him.

"You do know who he is," he said reproachfully. "The hotel mogul? The resort developer? The billionaire?"

"Of course I know who he is," Molly said. "I read the papers. But what's so new about this? You told me a year ago that you were doing a profile on him. You said that the Miami Herald wanted to run it in their Sunday magazine. Last I remember, you were busy interviewing all his former girlfriends."

"Not all of them," Carter said. "that would have been physically impossible if I wanted to publish in this decade. Anyway, it was getting redundant. They all said some version of the same thing. 'Jake was always a gentleman, but I could tell that underneath it all, deep emotional wounds were preventing him from ever trusting me with his heart.' " He rolled his eyes. "Yawn. Spare me, please, from the pop psychobabble of a bunch of models."

Later in the excerpt, Molly questions her journalist friend on why he would write about a billionaire womanizer:

"He sounds like a shallow playboy. Why don't you pick someone more worthy to write about?"

Carter grinned. "He's worth one point one billion dollars on a good stock day. That's worthy enough for me."

Craft's other books are "Trust Me" (2003) and "A Hard-Hearted Man" (1998).

E-mail Carolyne Zinko at czinko@sfchronicle.com and Carrie Kirby at ckirby@sfchronicle.com.

This article appeared on page A - 1 of the San Francisco Chronicle