Toyota Motor Corp. overtook Ford Motor Co. as the second-biggest U.S. automaker, after Ford’s sales dropped 14 percent last month. General Motors Corp. posted a surprise gain of 6.1 percent as it sold more pickups.

Toyota’s sales declined 2.8 percent to 233,471, while Ford’s slid to 217,170 cars and light trucks. GM said in a written statement that its total on that basis rose to 385,529. Chrysler LLC’s fell 6.1 percent to 168,203, Nissan Motor Co.’s climbed 6.3 percent to 95,527 and Honda Motor Co.’s gained 4.7 percent to 158,342.

Ford, which has held the No. 2 rank in annual sales since 1931, went into last month with a lead for this year of 9,597 cars and light trucks over Toyota. Ford, GM and Chrysler in July held less than half of the U.S. market for the first time, and analysts estimated that sales of each would drop again in August.

“It’s inevitable that Ford will get passed by Toyota,” said Bradley Rubin, an analyst with BNP Paribas in New York. “They are trying to focus less on rental sales, which aren’t as profitable, and that’s a good thing.”

Toyota’s sales of cars and light trucks through August were 1,788,603. Ford’s on that basis were 1,781,815. Including medium- and heavy-duty trucks, Ford sold 1,792,229 vehicles this year.

Ford’s August sales decline for cars included a drop of 36 percent for the Mustang sports car and a decrease of 15 percent for the Focus small car, the company said in a written statement. Ford has been reducing low-profit deliveries to fleet customers such as rental companies.

The company’s truck sales, including medium- and heavy-duty models, fell 2.4 percent to 153,468. F-Series large pickup trucks, which account for almost a third of Ford’s total sales, declined 9.9 percent to 69,220.

Ford said it plans to increase fourth-quarter production in North America 5.6 percent to 640,000 vehicles. In 2006’s final quarter, Ford had slashed output 24 percent, the largest decline since the 1980s, to clear dealer lots of unsold cars and trucks.

Toyota’s sales fell from 240,178 a year earlier, the Toyota City, Japan-based company said in a written statement. Jim Lentz, executive vice president of its U.S. sales unit, said “reduced credit tied to the subprime squeeze challenged consumer confidence this month.”

Sales at GM, the largest U.S. automaker, rose 17 percent for light trucks while declining 7.8 percent for cars, the company said in a written statement. Including medium- and heavy-duty trucks, Detroit-based GM’s total climbed 5.3 percent to 388,168.

Sales of Chevrolet Silverado large pickups increased 32 percent to 67,486, the automaker said. The gain for GMC Sierra large pickups was 34 percent. GM increased average incentives on its pickup trucks by $440 a vehicle last month from July, company sales analyst Paul Ballew said on a conference call.

Chrysler’s decline, from 179,165 a year earlier, was the Auburn Hills, Michigan-based automaker’s first monthly report since DaimlerChrysler AG sold an 80.1 percent stake in the company to Cerberus Capital Management LP on Aug. 3.

Nissan’s sales of Nissan and Infiniti vehicles rose to 95,527 from 89,848 a year earlier, Mark McNabb, U.S. sales chief for the Tokyo-based company, said in an interview.

Honda said its sales for August were its best for any month. The Tokyo-based automaker said in a written statement that it benefited from gains for Fit subcompacts, midsize Accords and CR-V small sport-utility vehicles.

Industrywide sales for the month may have fallen to 15.8 million cars and light trucks, the average estimate of analysts and 22 economists in a Bloomberg survey. The rate was 16.1 million in August 2006, according to Bloomberg data.

The analysts had estimated August declines of 12 percent at Ford, 5.9 percent at GM and 5.8 percent at Chrysler.

The effect of defaults in the subprime mortgage market probably added to automakers’ woes in August. Loans have become more costly and harder to get in the wake of the subprime mortgage crisis, prompting some analysts to lower their forecasts for auto sales.

Brian Johnson, a Lehman Brothers analyst in Chicago, reduced the low range of his estimate for industry sales this year from 16.4 million vehicles to 16 million, which would be the lowest since 1998.

“Cars run on gasoline, but car sales run on credit,” Mr. Johnson said in a note to investors. “There has been a systematic tightening of credit standards” for auto loans during the past year.