– Sales in June fell 7 percent at Fiat Chrysler Automobiles, 5.1 percent for Ford and 4.7 percent for General Motors amid a broader industry decline now entering its sixth consecutive month.

Sales of Ford sport-utility vehicles such as the Explorer, Edge and Flex were strong during the month but were not enough to overcome the 23 percent drop the automaker saw in car sales. The story was similar for GM, where a number of new or recently launched SUVs, such as the Chevrolet Equinox and Buick Envision, could not counteract falling sales of cars such as the Chevrolet Cruze, Malibu and Impala.

At Fiat Chrysler, sales rose 6 percent for Ram and soared for the Alfa Romeo brand but fell 11 percent for Jeep, a surprising decline for a brand that sells nothing but SUVs.

"Yes, Jeep is shifting around its models, but this is Jeep's market and one you would think they would be able to capitalize on," said Michelle Krebs, a senior analyst for AutoTrader.com.

Among Asian automakers, sales increased 2.1 percent for Toyota, 2.0 percent for Nissan and 0.8 percent for Honda. Meanwhile, German automaker Volkswagen, recovering from its diesel emissions scandal, said its sales increased 15 percent in June.

While automakers are still selling cars at a healthy pace, they are spending more money on incentives and using longer lending terms to do so, leading to concerns that sales are poised to fall faster than they were expected to at the beginning of the year.

Edmunds.com, Kelley Blue Book and LMC Automotive all predict overall industry sales in June will fall between 2-4 percent. The projections translate to a seasonally adjusted annualized selling rate of 16.5 million, the industry's weakest first half of a year since 2014.