GM said the hold is unlikely to affect its adjusted earnings guidance of $13 billion to $15 billion for 2022.
In the second quarter, GM dealerships delivered 578,507 vehicles, compared with 683,696 a year earlier.
GM's second-quarter market share grew an estimated 1 percentage point to 16.3 percent, the automaker said, citing J.D. Power data.
"Our long-term momentum will continue to build thanks to the launches of groundbreaking new EVs like the GMC Hummer EV and Cadillac Lyriq, and the tremendous customer response to the Chevrolet Silverado and GMC Sierra," Carlisle said.
GMC delivered 272 Hummer EV pickups during the quarter. The brand sold about 100 Hummers during the first quarter. The Lyriq has been rolling out this spring and summer, with no sales reported yet in the U.S.
GM said it will gradually increase production of the electric vehicles during the second half of the year. Ultium Cells — a joint venture between GM and LG Energy Solution — will begin making battery cells in Ohio in August.
Despite low inventory levels, the heavy-duty Silverado pickup had its best first half in retail sales since 2007, and the heavy-duty Sierra pickup recorded its strongest first half ever.
Overall, deliveries for Chevy, Buick and GMC dropped by double digits, with Buick facing the steepest decline, at 56 percent. Cadillac deliveries fell 6.7 percent.
Brands: Buick, down 56%; Cadillac, down 6.7%; Chevrolet, down 10%; GMC, down 14%
Notable nameplates: Buick Enclave, down 48%; Envision, down 56%; Encore GX, down 65%; Cadillac CT5, up 70%; Escalade, down 15%; XT5, down 37%; Chevrolet Blazer, down 31%; Bolt EV/EUV, down 38%; Colorado, up 52%; Silverado (light duty), down 24%; Traverse, down 54%; GMC Sierra (light duty), down 37%; Terrain, up 37%; Canyon, up 40%; Yukon, down 28%
Incentives: $1,847 per vehicle, down 58% from a year earlier, TrueCar says.
Average transaction price: $50,558, up 9.3% from a year earlier, according to TrueCar.
Fleet mix: 22%, compared with 14% a year earlier. GM's pre-pandemic fleet mix was about 20%. Commercial, government and daily rental deliveries increased 29% combined. Commercial and government deliveries made up 73% of the fleet sales mix.
Inventory: 247,839, up from 211,974 a year earlier.
Did you know? Cadillac is accelerating production of the Lyriq electric crossover, with initial deliveries in process. Orders for the 2023 Lyriq are sold out, and Cadillac opened orders for the 2024 model last month.