MILLIONS of children pick up Lego bricks each year to spend hours - 5 billion, in fact - creating their own imaginary worlds.

Now the manufacturer of the little plastic playing blocks wants to take them online to "Lego Universe," a virtual world for fans of the ubiquitous toy.

Lego Universe joins an established trend where toys and video games are cross-promoted, such as Nintendo Co Ltd's Pokemon TV show, game card, toys and video game franchise, and Mattel Inc's Barbie online shopping and gaming portal at barbie.com.

To launch next year as a massively multiplayer online game, or MMOG to those in the gaming community, Lego Universe will let players create online versions of themselves and interact with each other.

"We want to make the connection between digital play and physical play," said Mark William Hansen who is in charge of Lego Universe. "The physical experience is our core, the digital experience will never replace the physical experience, but it's a nice add-on."

Hansen, speaking at the headquarters of Europe's largest toymaker, said he had been working on his doctoral thesis with Lego Group on mass customization and ended up joining the family-owned company to create the game.

Photographs: Stock Xchange