Japan's top mobile phone operator, NTT DoCoMo Inc., is negotiating with the world's largest Internet service provider, America Online Inc., to tie up in online business for cellular phones, it was learned Wednesday.

Industry sources said that if the deal is inked, NTT DoCoMo -- part of the Nippon Telegraph and Telephone Corp. group -- would provide technology and knowhow regarding its popular i-mode Internet access service to AOL, while gaining access to information content that AOL currently provides to personal computer users.

Launched in February 1999, i-mode has gained popularity in Japan, with over 8 million subscribers. NTT DoCoMo has 30 million subscribers.