The CLA starts at $30,825 with shipping. The GLA is expected to be priced higher, but still several thousand dollars less than the GLK.
The GLA will be launched with all-wheel drive and later offered with fwd. The high-performance GLA45 AMG debuted last week at the Detroit auto show.
With growing demand for premium crossovers, Cannon said the GLA could be even hotter than the CLA.
"Dealers feel there is a lot more potential in that car," he said. "It could be hotter -- the feedback is phenomenal."
The GLK had a conquest rate of more than 60 percent when it was launched in 2009, and Cannon said he expects the GLA's percentage to be higher.
Meanwhile, Daimler AG CEO Dieter Zetsche said Mercedes is looking for ways to boost production for all its new fwd compact cars, including the A- and B-class hatchbacks sold in Europe.
The automaker will likely add a third shift at the plant in Hungary that makes the CLA, but Zetsche admitted not much can be done to increase production of the current-generation compacts.
"Scarcity is not the worst thing for a product," he said. "You do not want to choke your pipeline."
The B class will be sold in the United States only as a battery electric car when it debuts this summer. Cannon said he does not expect high volumes, but he would not give sales targets.