'I think one company will come out on top when all this shakes out,' ACNielsen eRatings.

com executive director for North Asia Forrest Didier said.

'There is room for one, maybe two of us.'

But ACNielsen eRatings.com - a partnership between ACNielsen and NetRatings - will not grab the lucrative measurement market without a fight. SAR start up iamasia was the first out of the blocks in the race to get established, releasing its survey results earlier this month.

ACNielsen's Hong Kong numbers will not be out until October.

Iamasia communications director Steve Yap said that as ask-no-questions dotcom investment money dried up and advertisers became more sceptical about audience claims, so there had been increasing interest in survey panels as a more reliable way to measure Web activity.

'I do not think it is a secret any more that there is tremendous market opportunity out there,' he said. 'There is going to be extreme competition as everyone strives to be seen as the single currency of measurement.'

Iamasia has been in business for only one year - started by former ACNielsen executive Kevin Tan.

By comparison, the American company has been in the television audience measurement business for almost 80 years.

Iamasia landed the first blow of the battle by having its numbers out more than a month ahead of everyone else, but ACNielsen is not showing any fear.

'I do not think it really matters to us,' Mr Didier said. 'Our goal is still to set the global standard.'

But the competition is not limited to a David and Goliath struggle between the small Hong Kong company and its US counterpart.

With no commonly agreed way of measuring Internet audiences, all of the large players are trying to establish themselves - and their technology - as the industry standard.

French firm NetValue also is moving aggressively into the Greater China region. In April, it established Hong Kong as its headquarters for regional operations - Hong Kong, the mainland, Taiwan, South Korea, and Singapore.

According to officials, the company intends to release its first Asian Internet data in October.

NetValue chairman for Asia Herve Le Jouan said the company has established itself in Europe and the US, and planned to dominate the Asian market.

Clients include Procter & Gamble, Microsoft, Yahoo!, Excite, Salomon Smith Barney, BNP Paribas and King Fisher.

While US-based Media Metrix has not announced plans to move into Hong Kong, industry sources expect the company to look at the Greater China market.

Jane Jung, Media Metrix's marketing communications manager, said the firm has been expanding globally and also laid claim to 'setting the standard for Internet and Digital Media measurement worldwide'.

At stake in this battle is the premier position in providing information which will help decide where online advertising dollars go.

By 2005, the Asian market - excluding Japan - is expected to be worth US$5 billion.

Panel surveys are used in much the same way as public-opinion polls.

A demographically representative group of participants is recruited in an area and software is installed on their computers to track online activity. The raw data is factored over the whole population to give a wider picture of what people are doing.

Iamasia, for example, has a survey size of 2,000 participants in Hong Kong. ACNielsen has 3,000. Overall, ACNielsen has 110,000 individuals under real-time measurement in the US, Japan, Australia, Britain, Singapore, New Zealand and Ireland.

Proponents see the method as far more accurate than traditional Web measurement which has relied on page hits and self-reporting by Web page operators - who often have been accused of inflating the numbers.

Jennifer Ho, a manager with PricewaterhouseCoopers in Hong Kong, said there was big demand for accounting methods which provided accurate data. Although her firm did not use survey panels, she said there was a role for them in the market.

'There are various Hong Kong Web sites which claim millions of hits per day,' she said. 'But we are seeing more and more scepticism in the market and people want to know what is really going on.'