China Unicom's below-par performance is taken by some as a sign that China's booming mobile market could be slowing.

The figures follow subscriber figures for February released earlier this week, which showed that a January spike in signups had waned.

About 20% of China's 1.2 billion people have mobiles, but phones may still be too expensive for most of the rest.

Growth

In general terms China still ranks as a fast-growth market, growing 2% in February.

It is already the biggest market in the world by subscriber numbers, with a 282 million customers.

China Mobile - a unit of the country's main fixed-line operator, China Telecom - has about two-thirds of these, with Unicom picking up most of the rest.

Like many operators, it gives subscribers free or deeply discounted handsets and then locks them into contracts.

Churn

The 8.3% fall in after-tax profits to 4.22bn yuan ($510m; �280m) is largely the result of 1.22bn yuan in one-off charges related to its paging business.

But churn - the number of customers defecting to other firms' services - is also increasing as competition picks up, particularly from low-cost intra-city wireless services.

Revenue per user has also weakened.