Software giant Oracle Corp. disclosed that another of its top executives defected from the company Friday, continuing a management drain that has raised investor concerns.

Jay Nussbaum is stepping down as an executive vice president of service industries after 10 years at Oracle to accept a job at one of the company's business partners, CEO Larry Ellison said in a memo to employees Friday. Without specifically identifying the company, Ellison said Nussbaum is "joining one of (Oracle's) largest and most important partners in a very senior role."

The company is in the Washington D.C. area, according to Oracle sources.

Nussbaum, 58, becomes the third top Oracle executive to leave the company during the past 17 months. The defections have worried investors who believe Oracle is better off with a group of seasoned executives to counterbalance the mercurial Ellison.

Last year, Ray Lane left as Oracle's chief operating officer after a falling out with Ellison. Gary Bloom, the executive who oversaw much of Oracle's push to become the world's leading maker of Internet software, departed a few months later to become CEO of a smaller Silicon Valley company, Veritas Software.

Like Bloom, Nussbaum apparently decided to leave because Ellison doesn't intend to step down as Oracle's CEO anytime soon. An Oracle spokesman said Nussbaum is leaving on "amicable" terms.

In Friday's letter, Ellison thanked Nussbaum "for all his hard work and sincere friendship over the past decade."

In previous interviews, Ellison has characterized the executive defections as a source of pride. He believes Oracle is becoming a high-tech version of General Electric, which has long been a training ground for executives who go on to run other companies.

Ellison will divide Nussbaum's position among four other Oracle executives: Kevin Fitzgerald, who will manage the company's higher education and health care business; Steve Perkins, who will manage government services; George Roberts, who will manage financial services, communications and utilities; and Keith Block, who will oversee the company's consulting division in North America.

Nussbaum leaves Oracle as a wealthy man. He cashed in $22.2 million in stock options during the fiscal year ending Aug. 31 in addition to his $1.4 million paycheck.