The Redwood Shores, California, company's software will allow the Japanese firms to deliver customized Web pages to customers' TVs through cable-television hookups.
The sale could be a key win for the Oracle unit, better known as NCI, as the company attempts to put together similar deals in the U.S. market. NCI competes with Microsoft's WebTV Networks unit, which has had moderate success in retail stores on the backing of huge advertising campaigns.
NCI's new customers include DDI Communication, a telco company, and the interactive cable service units of Mitsubishi Electric, Marubeni, and Sumitomo. The set-top boxes will be supplied by Acer and distributed through the individual companies, NCI said.
End users will be able to use smart cards to access custom Web pages and eventually could customize the device's graphical interface as well.
Financial terms of the agreements were not disclosed. Together, the four telecommunication companies can reach as many as 13 million Japanese households, NCI said.
Reuters contributed to this report.