Can a new-and-improved Mario and an elite squad of “Halo” troopers lead a successful battle against the recession? The video-game industry is about to find out.

After initially proving resilient to the economic downturn, sales of video game hardware, software and accessories have suffered six straight monthly declines in the U.S. — pointing to a difficult struggle ahead as game companies prepare for the critical holiday shopping season.

Microsoft Corp., Nintendo of America and Sony Computer Entertainment America have all cut prices on their consoles in recent weeks as part of the natural lifecycle of video-game hardware. That promises to help overall unit sales during the holiday season, but the lower prices could still translate into reduced revenue in the end.

Overall, video games promise to fare better than many other sectors over the holidays, but analysts say the industry will still feel the effects of the tough economic times.

“An awful lot of merchandise is still going to go out retailer doors this holiday season, because video games are still at the top of many kids’ wish lists,” said Michael Goodman, an independent video-game consultant in Boston, Mass. “But maybe instead of getting two games, you only get one game. Or instead of getting a peripheral, you just get a game. Those are the kinds of decisions I think parents are going to be making.”

The direction of the overall industry has significant implications for the Seattle region, which includes Microsoft’s Xbox and game divisions, Nintendo’s American headquarters and many independent game developers. A 2007 study by the Washington Interactive Network found more than 15,000 video-game related jobs in the region and more than 150 companies or divisions involved in games.

Through August, total 2009 sales of video game software, hardware and accessories were $9.07 billion in the U.S. — down 14 percent from the same period last year, according to the NPD Group market research firm.

Rather than taking lots of big risks on new franchises, game publishers and console makers are leaning heavily on new adaptations of tried-and-true titles — tapping into well-established audiences. Nintendo, for example, will release “New Super Mario Bros Wii” on Nov. 15, updating the venerable game for the Wii console and its motion-sensitive controller.

Nintendo is billing it as the first Mario game with a true multiplayer mode. Cammie Dunaway, Nintendo of America’s executive vice president of sales and marketing, said the company hopes the game will appeal to new gamers, potentially lifting sales of the Wii, but also to experienced gamers who already own one of the Nintendo consoles.

“It’s one of these Nintendo games that operates on multiple levels,” Dunaway said.

Other key titles coming from Nintendo include Wii Fit Plus, due out Oct. 4, a new version of the software for its pressure-sensitive Wii Balance Board accessory.

Microsoft, meanwhile, will be looking for a continued boost from “Halo 3: ODST,” the recently released new installment in the blockbuster science-fiction-based, first-person shooting game for its Xbox 360 console. Other key titles will include “Forza 3” and “Left 4 Dead 2.”

Sony’s PlayStation 3 will also be counting heavily on sequels, including “UNCHARTED 2: Among Thieves” and “Ratchet and Clank Future: A Crack in Time.” The company says more than 25 exclusive titles will be available for PlayStation platforms this holiday and early next year.

Anita Frazier, an NPD Group analyst, said the gaming companies would likely be leaning on sequels regardless of the economic situation.

“Well-known and loved franchises are the bread and butter of the industry and new franchises are risky, as always. I also don’t think the economy is playing a part here,” she wrote in an email. “Remember that most games take two-plus years to develop, so games planned for this holiday would have been in development prior to the economic meltdown.”

At the same time, analyst Goodman noted that some future new games that might have been given the go-ahead in better times were no doubt axed behind the scenes this year because of the economy.

Sony’s console is in third place behind No. 1 Nintendo and No. 2 Microsoft in the battle for market share. Sony kicked off the recent trend of console price reductions by dropping the price of the 80GB PlayStation 3 by $100 to $299.99 in August, and introducing a new PS3 “Slim,” with a 120GB hard drive, for the same price. The company said subsequently that unit sales of the PlayStation 3 had risen by 300 percent following the price drop.

Microsoft on Aug. 28 dropped the price of the 120GB Xbox 360 Elite by $100, to $299.99. (The company also offers the Xbox 360 Arcade model, without a hard drive, for $199.99.) In addition, the company has been offering a rebate that effectively drops the price of the Xbox 360 Elite by an additional $50 until Oct. 5.

“At $249 the Elite is a great value and we certainly expect a lot of consumers to respond positively to the offer,” said David Dennis, a Microsoft spokesman. Microsoft cites NPD data showing that Xbox 360 unit sales in the U.S. rose nearly 17 percent in the first eight months of this year, making it the only console to show overall growth during that time period.

Console makers traditionally decrease the price of their hardware after it’s on the market for a number of years, as the cost of manufacturing declines and they need to reach a broader audience. Nintendo followed Sony and Microsoft on Sept. 27 by droping the price of its Wii console to $199.99. Nintendo had charged $249.99 for the console since its launch nearly three years ago.