NEW YORK (TheStreet) -- The U.K. is Europe's second largest auto market and investors are concerned that Brexit will have a negative impact on the entire European auto sector.

Shares of the big three companies, Ford (F), General Motors (GM), and Fiat Chrysler (FCAU) have been declining due to investors' fear that sales will slow down in Britain and eventually across Europe, reported Phil Lebeau on CNBC's "Closing Bell."

European automakers such as BMW, Volkswagen, and Daimler are down more than 11% as a result of what is happening in Europe, he said.

"These are some ugly numbers," Lebeau noted.

Britain's luxury automakers such as Bentley, Rolls Royce and Aston Martin shouldn't be too effected by the Brexit.

"Their biggest market southern California, Shanghai, the place where the ultra-wealthy live around the world. Those large markets, sales expected to remain robust," said Lebeau.

European carmakers have not made a decision to relocate operations yet and Lebeau says they probably won't any time soon.

"Keep in mind with some of the British automakers, they're owned by the European automakers. They're owned by BMW and Volkswagen and not moving the operations. Aston martin, it is where it's at and not planning to move the operations any time soon," Lebeau said.

The U.S. automakers with the most exposure to Europe are going to feel the most pressure, he added.