LOS ANGELES — The shelves are crammed with boxes of baseball cards at Mike Mittrick's store. It gives his customers lots of choices, but also illustrates how the hobby's landscape had become cluttered and confusing for collectors.

Faced with declining revenue over the past decade, the baseball card industry — once composed of four major manufacturers — has been halved in a matter of months.

One company closed its doors. Another had its license to make products in 2006 dropped, and the oldest, most recognizable brand was rumored to be up for sale.

Insiders hope the shakeup will bring the struggling industry out of its slump and help reclaim its main demographic — boys who are spending their money on other diversions such as video games and the popular Yu-Gi-Oh! game cards.

"We felt the best way to position it for growth was to have fewer manufacturers producing cards," said Evan Kaplan, director of trading cards and collectibles for the Major League Baseball Players Association, which along with Major League Baseball charges manufacturers licensing fees to produce cards.

"We don't expect it to get back to the way it was like in the 1950s or 1960s, but this new model will be better than we have now," Kaplan said.

The downsizing is a mixed bag for retailers such as Mittrick, who runs 52 Mantle Card Co. in the Orange County city of Brea. He opened his store in the early 1990s, when the sports card industry posted revenue of more than $1 billion as speculators scooped up cards hoping for a big return on their investment.

Baseball cards then comprised 80 percent of the industry's revenue but now account for less than half — an estimated $120 million.

The rising cost of cards has played a major role in the decline. Collectors spent between 89 cents and $3 on a pack of cards in the mid-1990s. Today, the average price is about $5 as companies include goodies such as autographs, small pieces of jerseys or even bat slivers in a small number of packs to drive sales.

Some packs guaranteed to have the extras can command up to $150.

"People just do not have enough disposable income nowadays to be able to spend a ton on cards," said Jeff Beals, 19, of Nashua, N.H., who estimates he spends about $200 a month on his hobby.

"If the companies place quality over quantity ... it will help the hobby a lot," he said.

Mittrick, 36, is one of the survivors. He said he sometimes makes only $5 to $10 profit on an entire box of cards. He's squeezed even more these days because his rent increased after he moved his shop to a new location. To supplement his income, Mittrick has been engraving plaques for the past couple of years.

Industry downsizing will allow him to trim the $6,000 a month he was spending to offer a competitive selection of cards. But it could also cut into his already shrinking profits.

"Life isn't any easier," he said. "I'm getting less customers because of the move, and now I will have fewer products."

Dwindling interest in the hobby coupled with exorbitant costs to put memorabilia into packs of cards helped sink New Jersey-based Fleer. Saddled with more than $30 million in debt, the company went out of business in May and rival Upper Deck of Carlsbad, Calif., bought its name and toy car business for $6.1 million at auction.

Fleer plans to auction off some of its remaining memorabilia this month to pay a list of creditors that includes dozens of professional athletes.

In July, collectors were stunned when MLBPA opted not to renew its contract for 2006 with Donruss/Playoff of Arlington, Texas. The company laid off 30 of its 100 employees but will keep making football cards.

MLBPA's decision leaves only Upper Deck and the publicly traded Topps, which has been around since the 1950s but recently announced a 20 percent drop in first quarter sales for its cards, collectibles and other entertainment products.