In 2007, the last year U.S. light-vehicle sales topped 16 million, 28 U.S. dealership groups raked in $1 billion or more in revenue, Automotive News reported.

Last year, only 17 did, according to the latest Automotive News list of the Top 125 Dealership Groups in the United States.

For dealership groups battered by last year's sales collapse, size offered no haven. That's one conclusion from a look at the Top 125 Dealership Groups.

The largest groups mostly held onto their rankings. Over the past five years, there have been more changes in the No. 11 through No. 20 ranks than in the top 10. Since 2004, the only new company in the top 10 arrived when the 2008 collapse of Bill Heard Enterprises let the Larry H. Miller Group of Cos. in Sandy, Utah, step up to No. 10.

But the top 10 got walloped last year.

All reported declines, often sharp, in revenue and new-car sales from a weak 2008, as 2009 U.S. industry sales fell 21 percent to 10.4 million.

Between 2007 and 2009, industry sales crashed 5.7 million units or 35 percent.

In those two years, the top 10 groups lost 38 percent of their combined new-vehicle sales, led by No. 1 AutoNation Inc. of Fort Lauderdale, Fla. Its 2007 sales of 328,963 new units fell 45 percent to 179,521. AutoNation's revenue fell 39 percent to $10.76 billion last year from $17.62 billion in 2007.

With unit sales off, cost cutting became the rule. No. 6 Asbury Automotive Group centralized many operations and moved its headquarters from New York to Duluth, Ga., outside Atlanta. Another publicly traded group, No. 4 Group 1 Automotive Inc. of Houston, says it trimmed $120 million, or 15 percent of its costs, in 2009.

All of the top 10 except privately owned No. 5 Van Tuyl Group of Phoenix; No. 7 Hendrick Automotive Group of Charlotte, N.C.; and No. 8 Staluppi Auto Group of North Palm Beach, Fla., reduced the number of dealerships they owned over the past two years. Some of that may have been cost cutting, but the elimination of brands by General Motors Co. and franchise cancellations by GM and Chrysler Group also played a part.

With fewer stores and lower industry sales, the ranks of dealership group giants dwindled. The number of dealership groups that sold 10,000 or more new retail units slid from 76 in 2007 to 42 in 2009.

Or consider fleet sales. Once they were the fast route to high sales: The factories sell the vehicles to fleets, and dealers handle the paperwork for a slim fee. In 2007, nine dealership groups, including three of the top five, had fleet sales of more than 10,000. That tumbled last year to just two dealerships that specialize in fleets: No. 49 Bommarito Automotive Group of Ellisville, Mo., and No. 54 Burt Automotive Network of Centennial, Colo.