Mercedes-Benz sold more than 2,300 CLA coupes in its first week of availability, helping the brand post a 7 percent September gain and widen its U.S. luxury-vehicle lead.
The CLA, which takes Mercedes into a new price category, stickers for $30,825, including shipping.
Mercedes also boosted E-class deliveries by 17 percent to 5,647 last month. Mercedes sold 24,697 vehicles, according to a statement.
Sales of the BMW brand rose 8 percent in September from a year earlier to 23,568. Deliveries of the BMW 7 series more than tripled.
The September results expanded Mercedes' lead over BMW for 2013 to 2,491 vehicles -- 215,056 to 212,565 -- up from a margin of 1,362 through August. BMW has sold the most luxury vehicles in the United States in the past two years.
The figures don't include Mercedes' Sprinter vans and Smart cars or BMW's Mini.
Lexus, the top-selling luxury brand in the United States for 11 years through 2010, slipped 4 percent in September. Deliveries slid to 19,522.
Cadillac sales rose 10 percent for the month to 13,828 vehicles.