June 24 (Reuters) - Auto dealer Group 1 Automotive said on Monday it is taking proactive measures to protect and isolate its systems from CDK's services, after the car-dealer software provider's platform faced outages last week.

"Despite the CDK service outage, all Group 1 U.S. dealerships continue to conduct business using alternative processes until CDK's dealers' systems are available," Group 1 Automotive said.

CDK said on Sunday it had begun work to restore its systems used by over 15,000 dealers across North America.

Bloomberg News reported on Friday that a group of hackers claiming responsibility for the attack on CDK's software systems had demanded millions of dollars in ransom to put an end to the hack.

CDK expects to restore its dealer management system in a few days while it's unclear how much time will be needed to resume other affected applications, Group 1 said. (Reporting by Kannaki Deka in Bengaluru; Editing by Mohammed Safi Shamsi)