"Mark was my close and irreplaceable friend, and trusted colleague," said the Oracle founder.
Shares of Oracle declined 5% after the software firm forecast current-quarter profit largely below Wall Street's estimates.
The transaction, valued at approximately $9.3 billion, is expected to close in 2016.
CEO Mark Hurd says the cloud business lets Oracle sell to clients without the budget for hardware or qualified staff.
The company has reported a higher-than-expected quarterly revenue as sales in its cloud business surged.
Going all in on cloud speaks volumes about the hand you're holding.
Oracle introduces a series of new and enhanced enterprise applications.
Dealmaker and finance guru Safra Catz would likely replace Larry Ellison if he were to leave Oracle for good, say Wall Street analysts.
Larry Ellison will be replaced by co-CEOs Safra Catz and Mark Hurd, but he will stay on as executive chairman and CTO.
The lawsuit accused HP of misleading shareholders about its commitment to ethics while its CEO was allegedly engaging in sexual harassment.
A shareholder claims a Facebook policy awarding directors over $150?million stock each annually is unreasonably generous.
Oracle has introduced Oracle Solaris 11.2, delivering modern cloud platform with integrated OpenStack distribution.