China Mobile Ltd signed up a record number of users in a single month in January, as the world's top cellular carrier built on its dominance in the world's largest wireless market.

But its shares slid 2.3 percent on Wednesday as investors -- who had piled into telecoms operators such as China Telecom as speculation mounted that Beijing was close to deciding on a long-awaited reshuffle of the industry -- cashed in their gains amid a broad market sell-off.

China Mobile, which has steadily devoured market share from its sole, smaller rival, China Unicom, for years, signed up 7.044 million subscribers last month, outpacing Unicom's relatively paltry 1 million-plus.

JP Morgan said on Wednesday that China Mobile could potentially exceed the U.S. investment bank's own prediction of about 6 million in average monthly subscriber additions for the firm in 2008, given a sterling January performance.

China Mobile now serves 376.38 million users -- more than the population of the United States. For more detail, please click on

here

The strongest-ever monthly growth, suggesting its enlarging monopoly in China's mobile telecom market, DBS Vickers wrote in a research note on Wednesday.

Such an impressive figure was mainly attributed to continual fixed-to-mobile migration and was also partly a seasonal effect from the Lunar New Year festival.

Unicom stock slid 3.6 percent, while fixed-line carrier China Telecom fell 3.6 percent.

Unicom's aggregate, post-paid GSM cellular service subscriptions level increased to 121.69 million in January, versus 120.56 million in December. Aggregated CDMA cellular service subscriptions rose to 42.23 million from 41.93 million in December.

For a breakdown of China Unicom's operational statistics for January, please click here (Reporting by Edwin Chan, editing by Ken Wills)