Oct. 24 (Bloomberg) -- Oracle Corp., the world's second- largest software maker, agreed to buy RightNow Technologies Inc. for $1.5 billion, gaining customer-service expertise to bolster a new Internet-based product.

RightNow investors will get $43 a share, Oracle said today in a statement. That's 20 percent more than Bozeman, Montana- based RightNow's closing price on Oct. 21.

The acquisition will add software that helps companies serve customers using call centers, Internet and social networks. Oracle is making its biggest purchase since Sun Microsystems Inc. last year after introducing the Oracle Public Cloud, which delivers software online via cloud computing, to spur demand for its programs.

'Oracle is getting serious about its own cloud,' said Richard Williams, an analyst at Cross Research in Livingston, New Jersey, who has a 'buy' rating on the stock. 'This is the first infrastructure buy, and it means they're putting the plumbing for the cloud together.'

Oracle gained 0.3 percent to $32.23 at 8:10 a.m. New York time before the opening of the U.S. markets. RightNow added 0.8 percent to $35.96 at the close on Oct. 21 and has advanced 52 percent this year.

'RightNow's leading customer service cloud is a very important addition to Oracle's Public Cloud,' Redwood City, California-based Oracle said in the statement.

After gobbling up more than 70 companies in a $40 billion buying spree, Oracle said this month it is focusing on smaller deals and building on its own products to find growth. Oracle embarked on its run of acquisitions in 2005 when it bought the human-resources software maker PeopleSoft Inc.

RightNow's acquisition is Oracle's biggest since the purchase of Sun Microsystems, completed in January 2010, according to Bloomberg data. Oracle has relied on takeovers to boost sales to $35.6 billion in the fiscal year ended in May.

To contact the editor responsible for this story: Peter Elstrom at pelstrom@bloomberg.net