Research In Motion Ltd. (RIM) is working with the world’slargest cellular phone service provider, China Mobile (Hong Kong)Ltd. to launch its popular BlackBerry mobile e-mail services inChina by the end of May, a spokeswoman said Thursday.

“We are now working very closely with China Mobile for thelaunch,” said Katie Lee, spokeswoman for RIM in the Asia-Pacificregion, in an e-mail.

The deal would make BlackBerry available to the world’s largestmobile phone market, giving RIM a shot at attracting a larger shareof the world’s users with its push e-mail services and devices.

The number of Chinese mobile subscriptions reached 404 millionat the end of February, according to Chinese governmentstatisticians. Over half of Chinese users rely on China Mobile fortheir wireless service, a total of 254.9 million as of the end ofFebruary, according to the company. The company alone has moremobile phone subscribers than the entire U.S.

Lee also confirmed that RIM has no relationship with a rivalservice in China called RedBerry.

The RedBerry push e-mail service was announced earlier thismonth by China United Telecommunications Corp. (China Unicom), thecountry’s second-largest mobile operator.

The company said it chose the name in part due to “people’sfamiliarity with the BlackBerry brand name” which it described asthe most successful application of push e-mail technology.

The BlackBerry service is currently available in several Asianmarkets, including Hong Kong and Singapore.