SmarTone Telecommunications Holdings and CSL have accused larger rival Hutchison Telecommunications of stalling progress towards an agreement that would allow video calls to be made across the operators' networks. A delay could hamper the development of the market for third-generation (3G) services. More mobile-phone users are expected to migrate to 3G in the second half, with Sunday Communications scheduled to launch its services in the second quarter. Without an interconnection agreement among operators, subscribers would be deprived of one of 3G's major benefits: the ability to place video calls. SmarTone, which launched advanced services last month, blames Hutchison for being unco-operative, saying it is delaying technical trials. Chief technology officer Stephen Chau said the trials should be a 'very straightforward task', as the competing operators were essentially using identical equipment. 'We have told them to [start the ball rolling] for interconnection ... technically, we don't believe there will be any problem but they are just not being co-operative.' According to Mr Chau, Hutchison has cited personnel changes for the delay. Earlier this month, Hutchison Telecommunications International, the listed telecommunications arm of Hutchison that oversees Hong Kong mobile operations, fired 270 employees. Mr Chau added that SmarTone completed technical trials with CSL in just 'one to two weeks'. A source at CSL also said Hutchison had been unco-operative in working towards video-call interconnection. Hutchison, which has signed up about 220,000 3G subscribers in Hong Kong, has little incentive to interconnect with its smaller rivals, which have signed up just a few thousand 3G customers so far. An industry analyst said this gave Hutchison the upper hand at the negotiating table. '[Hutchison] can lay tough demands on the interconnection terms ... the tables may turn only when SmarTone and CSL can successfully migrate additional 2G subscribers to 3G.' Agnes Nardi, the managing director of Hutchison Telecom, hit back at the criticism by saying an interconnection agreement depended on how the other two operators 'progress with their respective technology'. In the meantime, SmarTone has called on the Office of the Telecommunications Authority (Ofta) to referee the dispute. 'If Hong Kong is to live up to its claim of being a liberalised telecoms hub, why can't [mobile users] interconnect yet with video calls?' Mr Chau asked. An Ofta spokeswoman said the regulator encouraged video-call interconnection among the operators. She said there were 'technical issues between two operators that had not been sorted out', without naming the companies. This is not the first time interconnection of services has been the subject of prolonged negotiations. In 2001, interconnection of short messaging services suffered an eight-month delay as the six mobile operators tussled over billing details.