Oracle is paying $220m in cash for Portal Software which makes billing and "revenue management" software.
The database giant is paying $4.90 a share or about $220m.
Charles Phillips, president at Oracle, said the combined firm offered the first end-to-end software suite for the communications industry.
Portal Software offers billing software which runs on Oracle databases. The company's staff will form a communications business unit at Oracle led by current VP of worldwide sales Bhaskar Gorti and Dave Labuda, Portal's founder, will become the unit's CTO.
Oracle hopes the combination of itself, for databases, Siebel, for CRM and now Portal for billing will sell well to communications and media companies.
In the last year or so Oracle has bought a bunch firms including: Retek, single sign-on firm Oblix, database maker TimesTen, database rival Siebel and Finnish developer InnoBase.
The takeover, subject to the usual regulatory approval, should close in June.
More details from Oracle here.®