Eager fans greet "Call of Duty" video game launch

* Fans line up for midnight release

* Game could be among top-selling of all time

By Gabriel Madway and Robert MacMillan

SAN FRANCISCO/NEW YORK, Nov 10 (Reuters) - Activision Blizzard Inc's (ATVI.O) hugely anticipated "Call of Duty: Modern Warfare 2" video game went on sale early Tuesday morning, welcomed by eager fans who lined up hours in advance of the release.

The first-person shooter game is set to be one of the biggest and fastest-selling titles in history, challenging records set by blockbuster releases from the "Grand Theft Auto" series.

This despite a dicey economic climate that is pinching consumer spending. Video game industry revenue in the United States, the world's largest market, is down 13 percent this year, according to industry tracker NPD.

But Call of Duty arrives amid high expectations and plenty of hype. Activision partnered with retailers including GameStop Corp (GME.N) and Best Buy Co (BBY.N) for more than 10,000 midnight store openings in North America.

At the GameStop store near Union Square in New York City, around 80 mainly young people were lined up Monday night ahead of the launch, some for two hours.

"This is the only game I'm probably going to do this for," said Paola Altamirano, 21, who was waiting in the queue. She said she planned to play Call of Duty against another friend online later that night.

With what Activision called a record level of preorders, there was little doubt about the strong demand for a game.

"Gamers are enthusiastic about picking this stuff up at midnight," said Paul Swiderski, who works at the Union Square Gamestop.

Analysts' sales estimates for the $60 game range from 11-13 million units by the end of 2009. Call of Duty is likely to account for a sizable chunk of Activision's profits in the fourth quarter, analysts say, so there is plenty at stake in the launch.

HARD-CORE AUDIENCE

The audience for the latest Call of Duty -- the sixth instalment in the franchise -- is primarily younger men, the gaming demographic that makes up the core of the estimated $50 billion global industry.

John Paneto, 20, was lined up outside a Best Buy store in San Francisco with about 10 others at around 10 P.M. Monday. He said he played a number of the other games in the Call of Duty franchise.

"I'm going to be up all night playing it, until I crash," he said.

Analysts say so-called hard-core gamers are unlikely to be dissuaded from buying a big-name title by economic concerns, as some casual gamers are.

But Call of Duty will have to turn in an impressive performance to top that of last year's mega-hit from Take-Two Interactive Software Inc (TTWO.O), "Grand Theft Auto IV." The title sold 3.6 million units on the first day, and 6 million in its first week or more than $500 million in sales.

Key to Call of Duty's success will be its international performance. Analysts say shooter titles are mainly popular in the United States and Britain.

And the game is facing little competition from other big-name titles. Industry watchers say Activision's rivals either pushed up the dates of their key releases or decided to delay them into next year.

Santa Monica, California-based Activision's stock, up more than 30 percent this year, closed up 2.6 percent at $11.54 on the Nasdaq on Monday. (Reporting by Gabriel Madway in San Francisco, with Robert MacMillan and Franklin Paul in New York; Editing by David Holmes)