Mobile phone carrier NTT Docomo and Amazon Japan said Wednesday that they launched a service in which NTT Docomo's "d Point" reward points can be earned and used on the Amazon shopping website.

It is the first time for Amazon Japan, a unit of U.S. e-commerce giant Amazon, to tie up with another company's reward points program.

NTT Docomo aims to attract users and expand the market scale of its reward points scheme through the collaboration.

Under the d Point program, users can earn points without subscribing to NTT Docomo's mobile phone service. The program had roughly 100 million users as of the end of March, according to the company.

Users who sign up online for the joint service can earn d Points worth 1% of the purchase amount, with a limit of 100 points, for each purchase on the Amazon site totaling ¥5,000 or more including tax. One point is equivalent to ¥1.

NTT Docomo subscribers who sign up for monthly membership plans of the Amazon Prime online video streaming service will be awarded 120 d Points every month.

"The d Point will become a points program even closer to people's lives," NTT Docomo President Motoyuki Ii told a joint news conference with Amazon Japan on Wednesday.

"The experience of earning and using points on Amazon will evolve to the next stage," said Jasper Cheung, president of Amazon Japan.