Oracle Corp struck a deal to buy RightNow Technologies Inc for around $1.5 billion, agreeing to pay a nearly 20 percent premium for the cloud-based customer service company.

Oracle said on Monday it would pay $43 for each share of RightNow. The company's shares closed at $35.96 on Friday.

Oracle said it expects the deal to close in late 2011 or early next year.

(Reporting by Michael Erman in New York, editing by Gerald E. McCormick)