More than 53 million people in Japan use a mobile device to access the Internet, according to comScore.

That is nearly equal to the 53.7 million who went online either at home or on a work PC.

"Mobile Web is a significant opportunity," said Maru Sato, managing director of comScore, Japan, in a statement. "Advertisers can now reach 53 million consumers online. The mobile audience is especially important to marketers trying to reach younger audiences."

Three-quarters of mobile Web users checked their e-mail by phone. More than one-half accessed news and information. An equal number searched or got directions from their handsets.

Japanese consumers still spend less time Web browsing on mobile phones than on PCs. Mobile phone Internet usage averages 8.1 hours per month versus 18.9 hours by PC. Internet users under age 34 accounted for 64% of mobile Web users and 45% of PC Web users.