Aales of its popular and eagerly anticipated title "Grand Theft Auto IV" reached more than $500 million in its first week, video-game publisher Take-Two Interactive Software Inc. said.

More than 6 million units of Grand Theft Auto IV were sold globally since the game was released April 29.

Only 3.6 million units of Grand Theft Auto IV were sold on its opening day alone, worth a retail value of $310 million worldwide.

"Grand Theft Auto IV" follows the criminal exploits of protagonist Niko Bellic, an immigrant-turned-gangster who travels from Eastern Europe to Liberty City, the game's fictional locale based on New York City.

As Bellic, players can hijack cars, earn cash for criminal activities, shoot innocent bystanders and visit strip clubs.

Critics say the extreme violence in "Grand Theft Auto" video games could be harmful to children, and Mothers Against Drunk Driving has complained that the latest version includes the ability to drive while intoxicated.