It was announced today that Japan’s largest mobile carrier, NTT DoCoMo, is partnering with Google to provide customers Internet searches and other services from the search engine giant. NTT DoCoMo currently uses its own i-mode to provide mobile Internet services.

By spring of this year, Google will be set as the default search portal page. Keyword-based advertisements will appear on search result pages through Google’s AsWords advertising platform. DoCoMo also plans to develop cell phones that can use Google’s Android mobile software. Android is expected to be available in Japan in the last half of this year.

NTT DoCoMo has nearly 53 million subscribers which represents more than half of Japan’s mobile phone market. In recent months it has struggled to sign-up new subscribers because of competition from KDDI and Softbank. These competitors have cut rates and conducted aggressive sales promotions.

Japanese cell phone subscriptions exceed 100 million, with 70 million users accessing the internet with their mobile phones. Yahoo Japan is currently the mobile search engine leader in Japan. This partnership will give Google better access to the Japanese search engine market.