In a move that has the potential to bring accurate global sales information to the gaming community, a new alliance has been formed between four industry leading market research firms – GFK (Europe), Chart-Track (UK), NPD (US) and Enterbrain (Japan) – to cooperate in providing a monthly “Top Global Markets Report.”

The reports are based on software point of sale data from the world’s three largest games markets and will track titles, unit sales, share, dollar sales and other stats. The first Top Global Markets Report reveals that Grand Theft Auto IV is the biggest seller this year to date, with a total of 6,293,000 units sold despite being released in late April and only in two of the three monitored regions.

The Nintendo Wii accounted for the second, third, and fourth best-selling games with exclusive titles Super Smash Bros. Brawl (5,433,000), Mario Kart Wii (4,697,000) and Wii Fit (3,604,000), while Guitar Hero III: Legends of Rock rounded off the list with 3,475,000 units.