Major U.S. search engines and Web directory operators Google Inc. and LookSmart Ltd. have increased their footprint in the Japan market with the signing of deals here this week.

Google has become the default search engine on Yahoo Japan, a site that claims top spot as the country's leading search engine. The deal represents Google's largest step into the Japanese market. Yahoo Japan counted over 10 million unique visitors in February and led the market with a reach of 72 percent, way ahead of its nearest competitor, the Nifty portal and ISP, which had 6.2 million unique visitors and a reach of 44 percent, according to data from NetRatings Japan Inc.

BTLookSmart, the joint venture of LookSmart and British Telecommunications PLC, has signed a deal to become the exclusive directory provider to Excite Japan Co. Ltd.'s search engine service. Excite's Japanese Web attracted 2.3 million unique visitors during February and had a reach of 16 percent, according to NetRatings.

The deals come as both companies are trying to expand their reach in Japan. Earlier this year both announced deals with NEC Corp. to integrate their respective search and directory services into the Japanese company's Biglobe portal, Biglobe is one of Japan's largest service providers. Google also launched this year a search engine for NTT DoCoMo Inc.'s hit I-mode wireless Internet service.