(Reuters) -CDK Global does not expect the cyber attack-led ongoing outage in its dealer management software, which dealers across the United States use, to be restored before the end of the month, according to a memo seen by Reuters on Tuesday.

The car industry technology and software provider would not be able to get all dealers live before June 30, and has asked them to make alternate plans for their month-end financial closing processes, according to the memo CDK sent to dealers.

The company, which reported the cyber attack last week, did not immediately respond to a Reuters request for a comment.

The ongoing CDK outage has forced some U.S. auto dealers to switch back to manual paperwork as the company works to restore systems used by over 15,000 retail locations.

The cyber attack has impacted about half of Volkswagen dealers and around 60% of Audi's dealers in the United States, according to a source familiar with the matter.

Honda, Toyota and Hyundai said they were monitoring the situation to understand the impact of the outage.

Honda added it has directed dealers affected by the outage to use alternate tools and processes that would allow them to continue to conduct business while CDK systems remain offline.

(Reporting by Nathan Gomes, Nora Eckert and Abhinav Parmar; Editing by Shinjini Ganguli)