Activision Blizzard, which broke video-game sales records last year with “Call of Duty: Modern Warfare 2,” has another blockbuster on its hands with follow-up “Call of Duty: Black Ops.”

Pre-orders at retailers like GameStop, Best Buy and Walmart had already led to very positive projections for the game’s first day of sales, with demand topping that for last year’s juggernaut.

As of Tuesday afternoon, Activision had yet to officially announce numbers for the game, produced by the Treyarch Studio.

But since the Cold War-set game, priced at $60, started flying off store shelves at midnight on Monday, more than 5 million people have registered to play it online against others, according to Activision insiders.

That would easily top the 4.7 million copies that “Modern Warfare 2” sold in its first 24 hours in North America and the U.K., taking in just north of $310 million — the single-day record for any entertainment release, not just a videogame. It earned $550 million by the end of the first week. That game bowed Nov. 10, 2009.

New title is similarly available on all gaming consoles.

The vidgame biz is eager for a major hit since overall game sales are down this year. One bright spot has been Microsoft’s “Halo: Reach,” which generated sales of more than $200 million in its first day of release in the U.S. and Europe, moving more than 3 million units. Game was exclusive to the Xbox 360.

Sam Worthington, Ed Harris, Gary Oldman and Ice Cube voice characters in “Black Ops,” while helmer-scribe David Goyer served as a consultant.

It’s the seventh installment in the “Call of Duty” franchise, which has earned $4 billion to date. Each year more retailers come aboard to promote the next outing, especially given last year’s surprise performance.

More than 4,400 GameStop stores were open to sell “Black Ops” at midnight, while Best Buy also had 700 stores ready to ring up sales.

Because it takes years to develop each “Call of Duty” installment, the game is divided among developers Infinity Ward and Santa Monica-based Treyarch, whose previous game, “Call of Duty: World at War” sold 13 million copies in 2008.