WASHINGTON – Toyota Motor Corp. and BMW AG show that automakers can reduce their impact on global warming without sacrificing sales or competitiveness, an environmental group said, according to the Associated Press.

Environmental Defense, a nonprofit environmental group, said in a report that the two auto manufacturers reduced their rates of carbon dioxide emissions from 1990 to 2005, while gaining market share in the United States by improving fuel efficiency across their lineup.

The performance of Detroit's automakers — General Motors, Ford and DaimlerChrysler — was mixed during the span, the report found, citing an increase by about 3- to 5-percent in the three companies' new fleet average carbon dioxide emissions rates since 1990.

Overall, the average carbon dioxide emissions rate from new vehicles dropped 3 percent from 2004 to 2005, Environmental Defense said, but remained up slightly since 1990. The study, based on government data, attributed some of the progress to improved gas mileage for trucks and a shift from truck-based SUVs to crossovers.

Toyota, which has heavily marketed its hybrid vehicles, saw its carbon dioxide emissions fall by 3 percent during the span while its market share increased 7 percent. Its fuel economy levels for passenger cars increased by 13.6 percent, helped by sales of the Prius and Corolla.

The Japanese automaker also saw its new vehicle carbon dioxide emissions in the U.S. grow by 125 percent during the period, the most of any automaker, but the group attributed it to increased sales. Since 2005, Toyota has aggressively sought to increase its profile in the truck segment through its launch of the Tundra pickup, according to AP.

BMW, helped by the success of its Mini Cooper coupe, improved its fuel economy by 14 percent during the period while drumming up sales. The German automaker has bumped up fuel economy on several vehicles, including the 5 Series, 7 Series and X5 SUV.

John DeCicco, senior fellow for automotive strategies at Environmental Defense, said Toyota and BMW offered “a clear example of innovative design paying off for the bottom line and the environment.”

General Motors Corp. and Ford Motor Co., as its market share declined in the U.S., saw a reduction in its overall “carbon-burden,” which measures the annual average carbon dioxide emissions over the lifetime of the company's vehicles.

DaimlerChrysler AG, which earlier this month sold an 80.1 percent stake in Chrysler to Cerberus Capital Management LP, saw its carbon-burden increase by more than 60-percent during the period as its market share increased.

Detroit-based automakers said they expected to see greater progress during the next few years as they retool their lineup to include more passenger cars and adopt more fuel-efficient technologies such as hybrids.

GM, Ford and Chrysler LLC are members of a partnership that has said mandatory emissions caps are needed to reduce the flow of carbon dioxide and other heat-trapping gases into the atmosphere.

Among other automakers:

• Nissan Motor Co.'s carbon dioxide emissions rates increased 9.2-percent during the period, the most of the top six automakers. The company's fuel economy levels for its trucks fell 17 percent during the span. Jeannine Ginivan, a Nissan spokeswoman, noted that since 2005 the company has introduced the subcompact Nissan Versa and the Altima Hybrid.

  
  

• Honda Motor Co. saw a 4.4-percent increase in its carbon dioxide emissions rates during the 15-year period, but the company remained the lead in fuel economy with a combined average of 29 mpg.