China will not allow paid-for calls between computers and conventional telephones for at least two years, according to the head of Tom Online, the Chinese internet portal which has a joint venture with Skype, the internet telephony company.

In the clearest indication so far of when charged telephone services based on the "voice over internet protocol" system will be launched in China, Wang Leilei, Tom Online's chief executive said the government "is not going to issue VoIP licences until 2008".

The news will be a disappointment to Skype, which told the Financial Times in November that it was in talks with Chinese telecoms operators which it hoped would clear the way for the launch of its computer-to-telephone service, dubbed SkypeOut.

Chinese fixed-line operators are concerned that SkypeOut, which allows users to make calls from computers via the internet to fixed-line or mobile telephones at lower rates, could undermine their core business.

Skype currently offers a free computer-to-computer telephony service to its 9m users in China, although calls are limited to five minutes. It also launched a free computer-to-telephone service about a month ago, which has signed up 10,000 users a day.

Mr Wang said that Tom Online, which claims to have more than 70m users, was not disappointed that it could not launch SkypeOut commercially.

"For Tom Online, our strategy is to grow our user base. With a big user base, there is a lot you can do. Revenue [from SkypeOut] is not important to us because we have not put in a lot of cost," said Mr Wang.

Mr Wang also said the company, controlled by Li Ka-shing, the Hong Kong tycoon, would consider acquisitions to lift its user numbers.

But he declined to comment on widespread rumours that Tom Online would merge with its rival Sina, which has 180m users worldwide.

"We have no comment on it. We love Sina. We love their user base," Mr Wang said. Tom Online, which currently generates most of its revenue from wireless services such as text and multimedia messaging, on Friday reported record revenue and profit for 2005 as Chinese mobile users downloaded more songs and ringtones.

Revenue grew by 40 per cent to US$172.11m and net income rose 32.7 per cent to US$45.01m.