Oracle Corp. announced on Wednesday that it will buy Portal Software Inc., a maker of billing and revenue management software for the communications and media industry, for $220 million.

The database and applications company is making a cash offer of $4.90 per share. Subject to regulatory and other approvals, the transaction is expected to close in June, Oracle said in its press release.

Portal's software enables communications companies to bill and manage a wide range of services, including wireline and wireless phones, broadband, cable, voiIP, and IP television, music and video.

Oracle said it will integrate its ERP applications and the CRM software it acquired through the purchase of Siebel Systems with Portal's billing and revenue management capabilities. Over time, Oracle may consider expanding the use of Portal's software in products for other industries.

Although attention has been mainly focused on Oracle's recent acquisitions in the open-source arena when it snapped database engine vendors Sleepycat and Innobase, the company has continued to steadily buy software companies: Retek in retail, i-Flex in financial services, and TimesTen and HotSip in the communications industry.

Oracle is also busy integrating the applications it gained through the multibillion-dollar purchases of both Siebel and ERP and CRM player PeopleSoft.

The bulk of Portal's customers, 96%, also use Oracle's database, and 57% of Portal customers use Oracle's applications. Portal's software is in use at 240 installations in 60 countries supporting more than 150 million subscribers.

Portal's management and staff will form a global communications business unit focused on billing and revenue management. Bhaskar Gorti, Portal's senior vice president of worldwide sales, services and marketing, is set to head up the unit, with Dave Labuda, Portal's founder and CEO, becoming the unit's chief technology officer.