Aug. 8 (Bloomberg) -- General Motors Corp., the largest U.S. automaker, lowered its forecast for U.S. industrywide sales of cars and trucks, citing the weaker housing market and higher gasoline prices.

The automaker expects sales of 16.5 million to 16.6 million, after estimating 16.6 million to 16.7 million on Aug, 1, Chief Financial Officer Fritz Henderson said today on a conference call. That includes medium- and heavy-duty trucks. Toyota Motor Corp. and Ford Motor Co. also have trimmed their forecasts.

A declining U.S. auto market may hurt GM, which already is losing sales at home to Asian companies led by Toyota. GM, based in Detroit, sold 9.4 percent fewer cars and light trucks this year through July from a year earlier, while Toyota's sales rose 6.1 percent. The industrywide total fell 3.2 percent.

``We have an industry that is clearly underperforming normal levels,'' GM chief sales analyst Paul Ballew said on the conference call. ``The combined headwinds of housing and energy prices are factors that continue to impact us in this market and will probably be with us going into 2008.''

For all of last year, sales of cars and light trucks were 16.6 million, according to Autodata Corp. of Woodcliff Lake, New Jersey. U.S. deliveries of medium- and heavy-duty trucks totaled 544,581 during 2006, according to Southfield, Michigan-based Ward's AutoInfoBank.

Toyota, Ford Forecasts

Toyota today forecast U.S. industrywide car and light-truck sales of 16.3 million this year, about 2 percent fewer than in 2006. Jim Lentz, the Toyota City, Japan-based company's U.S. sales chief, said Toyota expects a rebound in 2008.

Ford yesterday cut its industrywide sales outlook for this year to 16.5 million to 16.8 million, including medium-and heavy- duty trucks. Its previous forecast was 16.8 million.

In January, GM chief economist Mustafa Mohatarem predicted U.S. industry sales of 17 million this year, including medium-and heavy-duty trucks.

The U.S. average retail price for regular gasoline rose as high as a record $3.22 a gallon in May and has averaged $2.73 this year, an increase from $2.66 a year earlier, according to U.S. government figures.

Forecasters including the National Association of Realtors have said the housing slump will persist into next year. The median new home price is expected to fall 2.3 percent this year to $240,800, the Chicago-based Realtors said today. That would be the first decline since 1991. New-home sales are projected to fall 19 percent to 852,000 this year.

Housing starts are considered a key indicator for sales of light trucks such as pickups. Light trucks are about 60 percent of GM's U.S. sales and about 53 percent of industry sales.

International Growth

GM hasn't posted a sales gain in the U.S. since 1999 and has been increasing international sales to offset declines in its home market.

GM may sell as much as 5.4 million cars and trucks outside the U.S. this year, an increase of about 8.7 percent from 2006, Ballew said. The automaker got 55 percent of its sales volume outside the U.S. last year. Chief Executive Officer Rick Wagoner has said he wants such sales to account for more than 60 percent of the company's global total.

Industry sales worldwide may reach 69.8 million this year, rising from 67.3 million in 2006, Ballew said. GM said it expects global sales of 81.4 million by 2011 and 94 million by 2016.

Henderson reiterated his comments from July 31 that GM will achieve $9 billion in cost reductions this year.

GM shares rose $1.34, or 4 percent, to $34.82 at 4:01 p.m. in New York Stock Exchange composite trading. Ford's gained 57 cents, or 6.9 percent, to $8.87. Toyota's American depositary receipts increased 81 cents to $123.22.

To contact the reporter on this story: Greg Bensinger in New York at gbensinger1@bloomberg.net

Last Updated: August 8, 2007 16:11 EDT