(Updated) Mark Hurd, Larry Ellison, Steve Jobs?

What exactly do these Silicon Valley executives have in common?

Ellison with wife No. 4. Photo via Sify Finance

Mark Hurd and Hewlett-Packard’s (HPQ) executive board might have thought the worst was behind them, but Oracle’s (ORCL) Larry Ellison couldn’t leave well enough alone.

Hurd stepped down Friday after an internal sexual harassment inquiry found that he had filed inaccurate expense reports, with all parties to the original claim agreeing that, as actress Jodie Fisher put it, “Mark and I never had an affair or intimate sexual relationship.”

Then, in an e-mail to the
New York Times
, the man whom the
Washington Post
once referred to as the “Lothario of the pocket-protector set” managed to keep the story alive for yet another news cycle by linking it to Apple’s (AAPL) Steve Jobs.

“The H.P. board just made the worst personnel decision since the idiots on the Apple board fired Steve Jobs many years ago,” Ellison told the Times. “That decision nearly destroyed Apple and would have if Steve hadn’t come back and saved them.”

Ellison criticized the HP board for taking the advice of its PR firm and ousting Hurd even though the board had, in Ellison’s words, “fully investigated the sexual harassment claims against Mark and found them to be utterly false.”

But Oracle has different ethical standards than HP — or, for that matter, Apple.

As the Times points out, Oracle president Charles Phillips is still holds his job after admitting earlier this year to an eight-year relationship with a woman other than his wife.

And Ellison also stays on as Oracle CEO despite a long history of office dalliances and at least one sexual harassment lawsuit (decided in his favor). Four times married and thrice divorced, the world’s highest-paid executive (total compensation over the past decade: $1.84 billion) has become a symbol of corporate excess in his own right.

Below: The Ellison section of a
Washington Post
feature about boardroom sex written at the height of the Clinton-Lewinsky scandal.

Sexual involvement with a subordinate can add to an executive’s mystique. One of the most envied men in Silicon Valley is Larry Ellison, 54, chief executive of Oracle Corp., one of the richest men in California. He’s the thrice-married Lothario of the pocket-protector set, frequently attending business events with a beautiful young subordinate on his arm. Some of his relationships have been with recent Stanford University alumnae in their first real jobs.

In his 1997 book, “The Difference Between God and Larry Ellison (God Doesn’t Think He’s Larry Ellison),” St. Petersburg Times reporter Mike Wilson described Ellison conducting simultaneous romantic relationships with as many as three female employees. That sometimes created confusion — Ellison openly described to Wilson an incident in which a woman employee arrived at the executive’s house one night, only to find another girlfriend-employee there.

Ellison’s most notorious romance ended up in court. A relationship bloomed when a junior-level marketing employee named Adelyn Lee encountered the boss in the elevator and asked him for a ride in his Ferrari, according to court testimony. Ellison offered, via e-mail, to let her drive. After 18 months, the relationship soured. Lee was then fired. She sued the company for wrongful termination and obtained a settlement, but was later jailed over allegations that she doctored e-mail messages she had used to bolster her claims.

Ellison has suffered no apparent repercussions from his behavior, and remains widely respected for his innovations in the computer industry. Oracle representatives declined to comment.

With a friend like this, do Hurd and Jobs need enemies?

UPDATE (1:57 p.m. Aug. 11): Although the original article made it clear that the sexual harassment suit against Ellison was decided in his favor and included more detail in the Washington Post excerpt, he complained that it was negligent because it didn’t say higher up what happened to his accuser. His e-mail is reproduced in full:

From:    Larry Ellison
Subject:    Hey Jerk
Date:    August 11, 2010 1:00:55 PM EDT
To:    PHILIP ELMER-DEWITT

Adelyn Lee went to jail for a year for falsely accusing me of sexual harassment. Why did you leave that out of your story you scum bag? Let me guess … your job is telling half-truths. Fortune Magazine must be very proud of you.