Net income climbed to S$41.9 million, or 4.7 cents a share, from S$38 million, or 4.2 cents, a year earlier, MobileOne said in a statement on Thursday.

Sales fell 8.6 per cent to S$186.4 million, reflecting the 'challenging' environment, according to the statement.

MobileOne's customers spent less on international calls as the global recession led to a decline in businesses.

'Roaming revenue, which makes up about 15 per cent of the total, would have been affected by slowing business activity and travel,' Kelvin Goh, an analyst at CIMB Securities, wrote in a report on April 14. He has an 'outperform' rating on the Singapore-based operator.

The wireless operator had to pay less tax after Singapore reduced its corporate tax rate to 17 per cent from 18 per cent.

MobileOne closed unchanged at S$1.47 in Singapore trading, before earnings were reported. The stock has dropped 0.7 per cent this year, while the benchmark Straits Times Index added 7.4 per cent.

'We expect operating conditions for the year to remain challenging in view of the continuing economic downturn and the resultant job losses and decline in economic activities,' Acting Chief Executive Officer Karen Kooi said in the statement.

The operator lost 11,000 mobile-phone customers in the first quarter, taking its total to 1.62 million as of March 31.

Average monthly revenue per user for post-paid customers fell 8.3 per cent to S$59.70 from S$65.10 a year earlier, MobileOne said. Prepaid customers generated average revenue of S$16.30 per month, 15 per cent less than a year earlier.