Motorola, the world’s second-largest mobile phone maker, could partner with a Japanese manufacturer to launch appealing phones that will help it boost its presence in Japan. The Chicago area-based communications technology company is setting its sights on one of the world’s most sophisticated mobile phone markets as well as other regions in Asia even as it solidifies its strength elsewhere. Japan accounts for less than 10 percent of global mobile phone demand but has been at the forefront of a global shift to high-speed mobile services since 2001, when NTT DoCoMo became the world’s first mobile operator to launch a commercial third-generation service based on the W-CDMA standard, one of two competing 3G formats.