Mobile telephone operators are likely to see a 10 per cent to 15 per cent rise in subscriber spending following last week's launch of wireless application protocol (WAP) services, according to an industry analyst. Tim Storey, Goldman Sachs executive director of Asia investment research, said the ratio of voice to WAP-spending could rise even higher in coming years as forthcoming electronic commerce applications may help to generate further revenues. All of Hong Kong's six mobile carriers plan to launch data-based WAP services - which include handset-accessible Internet, messaging and e-mail - in the next three months. Mr Storey predicted WAP and other data-based applications would generate $2.4 billion in revenues for SAR mobile operators by 2003. By that time, about 30 per cent of the estimated 1.6 million cellular subscribers in Hong Kong would be using WAP applications, he said. Stock prices of SAR mobile operators are likely to rise as more advanced services are released. Japanese mobile operator NTT DoCoMo launched a data-based service similar to WAP, called i-Mode, in February and subsequently saw its share price rise 309 per cent. 'We've seen a huge increase in the market for stocks like SmarTone (Communications),' Mr Storey said, although he declined to comment on whether telecommunications stocks in Hong Kong are overvalued.