Variety is reporting that Grand Theft Auto IV, like many assumed a month ago when pre-sales went through the roof, has surpassed ‘Halo 3′ and ‘Pirates of the Caribbean: At World’s End’ to be the biggest opening week of an entertainment product ever.

Publisher Take-Two Interactive is set to confirm today that “Grand Theft Auto IV,” from its Rockstar Games label, sold over six million units in its first week, grossing over $500 million in consumer sales.

‘Halo 3′ grossed $300 mill in its first week, but it was only available on the XBOX 360, while Grand Theft Auto is also available on the Sony Playstation 3. ‘GTA IV’ sold roughly 3.6 million units in its opening weekend, worth about $310 million.

The $500 million-plus figure is even higher than the $400 million that sources close to Take-Two had been expecting based on retailer orders several weeks ago. Daily Variety, April 16)