LOS ANGELES — High oil prices may be driving down U.S. car sales, but Japanese automakers that depend on the U.S. market for the largest portion of their profits say the adverse conditions could present them with a business opportunity.

The spread of ecology consciousness as well as recent high gasoline prices are prompting consumers in California to buy more energy-efficient cars instead of light trucks, pickup trucks and large sport utility vehicles.

The trend is benefiting Japanese carmakers, which have had a competitive edge in compact car sales over the U.S. Big Three — General Motors Corp., Ford Motor Co., and Chrysler — carmakers and dealers in California said.