Fred Meier

USA TODAY

Cadillac will unveil a high-performance "V" version of its ATS rear-drive compact sedan at November's 2014 Los Angeles Auto Show.

The smaller V will be a sibling, at least in spirit, of Caddy's hot CTS-V line that is the brand's racing model.

The ATS is Cadillac's entry in the competitive small premium sport sedan segment pioneered by and still dominated by BMW's 3-Series. The ATS-V, which would go on sale next year, would be a direct rival for the high-performance "M3" version of that BMW.

Cadillac confirmed the November debut for the ATS-V, but has not provided details of the coming performance model, nor has it said what will power it.

The power plant is widely expected to be a new-design, twin-turbo, 3.6-liter V-6 that was introduced in the V-Sport model of Cadillac's redesigned 2014 CTS midsize sedan. In that CTS model, the V-6 puts out 420 horsepower and 430 pounds-feet of torque and gives the sedan a 0-to-60 mph time of 4.4 seconds, according to Cadillac.

Dropping it into the smaller, lighter ATS should create a sedan hot enough to be a credible rival to the BMW M3, which is powered by a 425 hp, 3-liter, twin-turbo inline 6.

The current CTS-V line — offered as a sedan, coupe and sport wagon — still is based on Cadillac's last-generation CTS and is powered by supercharged 556 hp., 6.2-liter V-8. It boasts a 0-to-60 mph time of 3.9 seconds, according to Cadillac.

The brand is expected to unveil the first model of a new CTS-V line, based on the new-generation CTS, in January at the North American International Auto Show in Detroit. The new CTS-V is expected to get a version of the 650 hp., 6.2-liter supercharged V-8 that powers the new "big nasty" Corvette Z06 reported on here last week.

Cadillac needs to build some new buzz around both the ATS and CTS. The ATS, the brand's new entry, made its debut as a 2013 model and got off to a fast start, but sales so far this year are down 20.8% from the period a year ago, according to Autodata. The CTS — all-new and a true midsize for 2014 — has sales through July this year up just 0.1% from the period a year ago.

Meanwhile, sales of Cadillac's SRX crossover — an aging design unveiled as a 2010 model and last freshened in 2012 — are up 15.7% year-to-date, and it is Caddy's top-seller. And sales for the big Escalade SUV, redesigned for 2015, are up 34.7% this year, according to Autodata.

The Los Angeles Auto Show opens with a media preview on Nov. 19.

Contributing: Kelsey Mays, Cars.com