The European Championship is the second-biggest sporting event in the world after the World Cup. However, audiences for the 2002 World Cup were lower than those for Euro 2000 because of the difference in time zones.
According to research from Initiative, TV viewing this time around will beat the cumulative audience for Euro 2000 across 21 European markets.
The 2000 event pulled in 1.59 billion people, with an average viewing audience per match of 51 million.
The agency predicts Euro 2004 audiences will be bigger because of growing interest in the sport outside Europe.
In the UK, ITV is selling spots in the England versus France game this Sunday based on the match attracting an average audience of 15 million, excluding pub viewing.
However, the media agency Carat is more bullish. It estimates the ITV game could attract 22 million home viewers, with an additional seven million watching in pubs. This represents a total of 52 per cent of the UK population.
There are eight broadcast sponsors this year and these will be rotated around the ad breaks, with two appearing on each occasion.
Unsurprisingly, games involving Germany, Italy, England and France proved to be the biggest draw in the Euro 2000 tournament. England's matches attracted a cumulative audience of 67 million viewers across the continent.
Initiative said the fact that these countries are participating in the tournament again - and that Russia is also expected to provide a huge viewing market - could result in record audience levels.