The new grand sedan is likely to take design cues from other contemporary Cadillacs like the CTS, pictured.

Detroit - As it strives to energise its Cadillac brand that once led the US luxury car market, General Motors has announced that it will launch a new "top-end, high-technology car" by the end of 2015.

The as-yet unnamed flagship sedan will be positioned "above today's CTS and XTS product lines," and "will add to rather than replace any model in the portfolio," GM said in a statement.

First sales in the United States are likely by the end of 2015, and sales in China about the same time, said Cadillac spokesman David Caldwell.

FOR THE TOP CLASS

The new odel will be in "the elite class of top-level luxury cars," said Cadillac President Johan de Nysschen in the statement. He added that the car, which is in development, will be rear wheel drive-oriented, using "completely new, custom-designed materials on a unique vehicle architecture."

De Nysschen came to GM this year and is charged with repositioning the 112-year-old Cadillac brand to truly compete with luxury leaders BMW and Mercedes-Benz.

The sedan's public debut will be in the first half of 2015. It will be built at GM's Detroit-Hamtramck plant, where the plug-in electric Chevrolet Volt, Opel Ampera and the Cadillac ELR are made, as well as the Chevy Malibu and Impala.

Cadillac sales through the end of August were 172 000 worldwide, up 10 percent from a year ago.

The top market for Cadillac remains the United States, but sales are growing quickly in China. It is those sales in China that allows for the development of the as-yet unnamed flagship sedan, Caldwell said.

TECHNOLOGY LEADER

The new Cadillac flagship sedan will compete with the Mercedes-Benz S-Class, BMW's 7-Series, and Audi A8.

GM is likely to use this Cadillac to introduce its latest technological developments, including the ability for the car to operate autonomously, said Caldwell.

But a true "self-driving" ability will not be available initially. Truly autonomous cars in mass production are still a few years away. Caldwell said when such a feature is offered, it is likely to be a high-end option.