NTT Mobile Communications Network has agreed to use Sun Microsystems' Java programming language in its new i-mode cellular phones, officials of the two firms announced Tuesday.

The two firms will conduct feasibility studies to develop applications based on Java and two other technologies that belong to the U.S. computer company.

Under the i-mode mobile phone system launched last month, subscribers can conduct banking transactions, reserve airline and concert tickets and exchange e-mail using their handsets.

The deal will pave the way for additional services such as upgrading security for financial transactions and the downloading of game software, according to NTT DoCoMo, the country's largest cellular phone carrier.

NTT DoCoMo plans to develop a prototype of cellular phones based on Java with Mitsubishi Electric Corp. by the end of this year with a view to introduce new services around the end of 2000, said Keiichi Enoki of NTT DoCoMo. The carrier also plans to use Java in its next-generation mobile phone system, IMT-2000, which is scheduled to start up in 2001.