By Jeff Green and Katie Merx Oct. 1 (Bloomberg) — General Motors Co. , Toyota Motor Corp. and Ford Motor Co. said sales fell in September as waning demand after the “cash for clunkers” rebates cut industry deliveries to the second-slowest rate this year. GM deliveries tumbled 45 percent, while Toyota dropped 13 percent, both worse than analysts had estimated. Ford slid 5.1 percent, and Chrysler Group LLC , Honda Motor Co. and Nissan Motor Co. also posted declines. “We knew sales would slow down significantly after the cash for clunkers surge,” said Stephen Spivey , senior auto analyst at Frost & Sullivan in San Antonio. “October will tell you what kind of rebound comes off that dip.” U.S. auto sales plunged 23 percent, and the seasonally adjusted annual sales rate fell to 9.22 million units, said industry researcher Autodata Corp. of Woodcliff Lake, New Jersey. July and August were the only months in 2009 when the sales pace topped 10 million, a level that Ford and researcher J.D. Power & Associates expect the U.S. to surpass for the year. The industry is coming off an August surge that snapped a streak of monthly sales declines dating to 2007. Buyers responded to the U.S. government’s offer of as much as $4,500 to trade in older, less fuel-efficient light vehicles from July 27 through Aug. 24, with almost 700,000 purchases. Shrinking Inventory Showroom visits fell after the $3 billion program helped empty dealers’ lots. With inventory at a 24-year low at the end of August, customers found fewer choices and automakers less willing to offer discounts. Analysts expected a sales rate of 9.3 million vehicles, based on the average of 8 estimates compiled by Bloomberg. Industrywide light-vehicle sales will be 10.3 million this year and 11.5 million in 2010, Westlake Village, California-based J.D. Power estimates. Last year’s sales were 13.2 million, after averaging 16.8 million this decade through 2007. The lowest pace this year was 9.11 million, in February. The annual rate is important to the industry because manufacturers, suppliers and dealers use it to compare monthly totals by taking into account seasonal buying patterns. September’s results brought the annualized sales rate in the third quarter to 11.5 million, the strongest since the same period a year earlier, when deliveries ran at an annual pace of 12.9 million units. Analysts’ Estimates Analysts’ sales estimates are adjusted for one more sales day this month than in September 2008. Unadjusted figures, used by Bloomberg and some automakers, would be about 4 percentage points lower. September sales at GM, the largest U.S. automaker, slid 47 percent on an adjusted basis, worse than the 44 percent decline projected by 6 analysts. Ford, the second-largest U.S. automaker, fell 8.9 percent on an adjusted basis, worse than the 5 percent average of 6 analysts’ estimates. The decline on that basis was 44 percent for Auburn Hills, Michigan-based Chrysler, matching the average of 5 estimates. Nissan’s adjusted decrease was 11 percent, compared with 2 analysts’ estimates of 7.1 percent, and Honda’s was 23 percent, worse than the estimates of 13 percent. Toyota’s adjusted decline was 16 percent, while analysts projected 13 percent. Light-Vehicle Totals U.S. light-vehicle sales for GM dropped to 155,679 from 282,806. Ford’s total including Volvo was 114,655 cars and trucks, compared with 120,788 a year earlier. Chrysler sales fell 42 percent to 62,197, down from 107,349. Nissan, which like Honda is based in Tokyo, said sales dropped 7 percent to 55,393 from 59,565. Honda said sales slid 20 percent to 77,229, compared with 96,626. Toyota, based in Toyota City, Japan, sold 126,015 Toyota, Lexus and Scion vehicles, down from 144,260. Hyundai Motor Co. , South Korea’s largest automaker, bucked the industry slide with a 27 percent increase. Seoul-based Hyundai said it sold 31,511 vehicles last month, up from 24,765 a year earlier. Industry deliveries totaled 745,997, Autodata said. Ford fell 24 cents, or 3.3 percent, to $6.97 at 4 p.m. in New York Stock Exchange composite trading. The shares have more than tripled this year. Auto sales improved later in September from early in the month as dealers restocked inventory and discounting picked up, said Jessica Caldwell , an analyst at auto-information provider Edmunds.com in Santa Monica, California. Edmunds raised its forecast for September’s annual pace to 9.34 million on Sept. 24, from 8.8 million a week earlier. Prices paid for GM, Ford and Chrysler vehicles rose by $2,000 on average in the second quarter as automakers slashed production, J.D. Power said. Incentives fell by 26 percent from March to August, according to Autodata. “The last two weeks of September could be an important indicator of the underlying rate auto sales are trending at,” Brian Johnson , a Chicago-based analyst at Barclays Capital, said in a note to clients. To contact the reporters on this story: Jeff Green in Southfield, Michigan, at jgreen16@bloomberg.net ; Katie Merx in Southfield, Michigan, at kmerx@bloomberg.net .