Mark Hurd says he decided that he needed to spend time focusing on his health.
Growth in Oracle's cloud-computing business, however, still lags behind rivals such as Workday and Salesforce.
"This market has no patience for any misses from tech companies, no matter how minor or how explainable the miss."
The company's shares drop more than 7% after its guidance for fourth-quarter cloud revenue misses analysts' expectations.
"Our pivot to the cloud is now clearly in full swing," Oracle co-CEO Safra Catz says.
The software giant reported cloud revenue rose 59% in the first quarter but the higher-margin software licensing business continues to sag.
Safra Catz will share chief-executive duties with Mark Hurd, but still focus on manufacturing, finance and legal operations.
The company’s top three executives are getting plenty of ink for refusing bonuses that were due them. But the eschewed amounts are so small, the motivation for the decision is murky.
