Car sales are declining across the sector but contrary to some analyst speculations, the struggling General Motors maintained its market share over Japanese automaker Toyota. Still, rising fuel prices at the pump are taking a toll, and drivers are making clear shifts away from once-coveted gas-guzzlers.

On Tuesday, United States automaker Ford Motor (nyse: F - news - people ) said sales of Ford, Lincoln and Mercury vehicles dropped by double-digit decreases in June, driven by steep declines in sales of trucks and sport utility vehicles under rising gas prices.

Sales fell 28.1% to 174,091 vehicles in June, compared to 242,029 in June 2007, including sales of all Ford, Lincoln, Mercury and Volvo models.

Investors were gloomy on the news, trading shares of Ford down 2.1%, or 10 cents, to close at $4.71 in trading in new York. The stock hit a 52-week low this week, and is down 50.0% since its year-ago price of $9.64.

Vehicle sales at General Motors (nyse: GM - news - people ) fell 18.5% to 265,937 units sold compared to 326,300 vehicles sold in June 2007, beating analysts estimates of 21.5% decline. After the stock hit a 54-year low last week, shares in Detroit-based General Motors continued to fall in the morning, but rallied 2.2%, or 25 cents, to close at $11.75 in trading on the better-than-expected results. In after-hours trading, the stock ticked up another 7 cents to $11.82.

Ford vice president James D. Farley, conceded that "the economy enters the second half of the year with a notable absence of momentum and a high degree of uncertainty." He added that rapidly rising gas prices and the consumer shift in preference toward fuel-efficient vehicles has posed challenges as well as opportunities for the capacity adjustments and the production of more cars and crossovers.

Sales in Ford's SUVs led the sales dive, plunging 55.0% to 10,424 units, followed by trucks and vans which dropped 37.8% to 55,006 units sold. Even sales of crossover utility vehicles dropped 15.8% to 28,688 vehicles, and Ford car sales fell 12.0% to 51,597 vehicles.

When customers do buy, they are picking smaller cars, crossovers and hybrids. The demand for more fuel-efficient vehicles has been a boon to Japanese automakers such as Toyota Motor (nyse: TM - news - people ) and Honda Motor (nyse: HMC - news - people ), which rely less heavily on trucks and sport utility vehicles than the Detroit Three.

General Motors' vice president of North America vehicle sales, Mark LaNeve, disagreed. "Make no mistake about this, Asian automakers do not have a monopoly on fuel efficient vehicles. Every month, more and more customers are choosing our brands when shopping for a high value, fuel efficient vehicle."

The numbers don't necessarily bear him out: In General Motor's most recent quarterly report, for the three months ended March 31, the company reported a 0.7% decline in U.S. market share to 22.1%, compared with 22.8% in the year-earlier quarter. The company attributed the decline to macroeconomic factors including higher fuel prices and a shift in customer demand from trucks and utility vehicles to passenger cars and crossovers. General Motors said new models in its portfolio of passenger cars and crossovers had performed well in the period.

When asked about the discrepancy between LaNeve's statement and GM's shrinking share of a declining market, GM spokesman John M. McDonald explained that his colleague was referring to a shift in perception among U.S. consumers from viewing the company as simply a truck manufacturer, and that only Asian automakers produce hybrid and other fuel efficient vehicles. He pointed out that GM's hybrid Chevrolet Tahoe, GMC Yukon 2-mode SUV and 295 Chevrolet Malibu--all hybrids--are brand new to GM's lineup and have been gaining popularity.

Since the vehicles are new to the market, comparable sales data was not yet available.

Some analysts had predicted that Toyota Motor could overtake General Motors in monthly U.S. sales for the first time in June but while both companies were hurt by a sluggish economy and poor sales of trucks and SUVs, General Motors retained its lead.

Vehicle sales at Toyota totaled 193,234 in June, down 21.4% from 245,739 vehicles sold in June 2007. Sales of the automaker's Prius hybrid actually fell 33.7% to 11,765 vehicles, which Toyota attributed to limited availability.

In tune with curbed discretionary spending elsewhere in the market, sales at Toyota's luxury Lexus division dropped 29.8% to 20,253 vehicles.

Shares of Toyota City, Japan-based Toyota Motor fell 0.4%, or 34 cents, to close at $93.66 in trading in New York. After hours, the stock rallied by a penny to $93.67.

The Associated Press contributed to this article.