Note: This story contains an added clarification of Oracle's investment in Eloqua, pertaining to "cash on hand."

Vienna, Va.—Oracle Corp. today agreed to buy Eloqua Inc., a provider of cloud-based marketing automation and revenue performance management software, for $23.50 per share, or approximately $871 million. Counting Eloqua's cash on hand that Oracle will gain with the acquisition, the effective purchase price is about $810 million.

The deal is expected to close in the first half of 2013.

Eloqua shares closed Wednesday at $17.92 on the Nasdaq.

The companies said the acquisition will allow marketers to provide a highly personalized and unified experience across channels, create brand loyalty and drive more qualified leads.

“Modern marketing practices are driving revenue growth and is a critical area of investment for companies today,” said Thomas Kurian, exec VP-Oracle development, in a press release. “Eloqua's leading marketing automation cloud will become the centerpiece of the Oracle Marketing Cloud and is an important addition to the Oracle Customer Experience offering, which includes the Oracle Sales Cloud, Oracle Commerce Cloud, Oracle Service Cloud, Oracle Content Cloud and Oracle Social Cloud.”

Eloqua clients include ADP Inc., Aon, Dow Jones & Co., Fidelity Investments, National Instruments and Polycom Inc. The company was founded in 1999 and went public in August.