China Unicom, the country's No?2 cellular carrier, is bracing for disappointing subscriber growth figures this month as the Sars outbreak accentuates last month's slowdown. China Unicom executive vice-president Shi Cuiming said: 'Since people hardly go out now, this will certainly affect our branches in signing up new users.' Because of the outbreak, China Unicom has halted a GSM 1X high-speed data transmission trial with Qualcomm in Suzhou, Jiangsu province. 'We stopped the trial because it's difficult to send our people there,' Mr Shi said. China Unicom, which operates global system for mobile (GSM) and code division multiple access (CDMA) mobile networks, was planning a commercial launch of GSM 1X later this year. Mr Shi said China United Telecommunications Group, the red chip's parent, was also monitoring the Sars situation to decide if it should delay its multi-billion yuan CDMA third-phase expansion plan. China United originally planned to invite equipment vendors to tender for the expansion by the end of the year. The plan would increase the network capacity to 50 million users and upgrade it into a 2.5G network. China United completed its second-phase CDMA expansion last month, doubling its network capacity to 35 million and upgrading to a CDMA 1X network. China Mobile chief financial officer Xue Taohai said Sars was affecting subscriber growth, especially in Beijing and Shanghai. But he believed the effect would be temporary. On Tuesday, the mobile duopoly revealed a slowdown in subscriber growth last month as the Sars outbreak deterred shoppers and promotions. China Mobile said its subscriber growth fell 16 per cent month on month to 1.7 million new subscribers last month, the smallest monthly increase this year. In the first three months of this year, the company added an average of more than two million new users a month. China Unicom saw a 5.6 per cent month-on-month decline in subscriber growth last month, with 1.183 million new users added to its GSM network, taking its total number of GSM subscribers to 58.063 million. It signed up 555,000 new CDMA users in April to bring the total to 8.58 million. In the past four months, China Unicom added only 2.335 million new users for its CDMA network.